Storm Australian Severe Weather Forum
Severe Weather Discussion => General Weather - all topics not current severe weather. => Topic started by: Harley Pearman on 02 February 2009, 01:22:52 PM
-
Drought Statements for 2009 - Victoria and South West New South Wales
During 2008, I researched the monthly droughts statements for the state of Victoria and inland New South Wales that showed that the drought afflicting areas of the two states did not properly break. The statements are found throughtout the General Weather Threads for New South Wales and Victoria. Given that this is still a serious and insidious weather event gripping parts of southern Australia, it may be appropriate to continue the topic as a separate heading for 2009 for as long as needed.
Victoria - January 2009
During the month of January 2009, much of the state of Victoria experienced exceptionally dry conditions, reversing any gains made in November and December. To show this:-
Melbourne experienced 0.8 mm of rain being the driest since 1932 when 0.3 mm fell. The long term average for the city is 48 mm. As at 30/1/2009, Melbourne had gone 27 days without rain, the longest dry spell since 1965 with a spell of 28 days.
(Source - Melbourne Sets Heatwave Record as Victoria Bakes, Bureau of Meteorology 30/1/2009)
Ballarat:- The city had 1 mm which is the lowest ever.
Much of western Victoria and North western Victoria had no rain. While January is usually a dry month for the state, average rainfalls were significantly below average:-
North West:- No rain received.
South west:- 1 - 10 mm averages.
Western Melbourne:- No rain received.
Eastern Melbourne:- 1 - 5 mm averages.
Gippsland:- 10 - 25 mm averages.
North east Victoria:- 50 - 100 mm strictly limited to the highlands.
Murray region 5 - 10 mm averages.
Deciles:
The west, south west and north west experienced very much below averages to a point of "Lowest on record" for some areas.
North east Victoria:- Below average falls.
North east highlands:- Average falls.
Anomalies:
Western 10 - 25 mm below average.
North west 10 - 25 mm below average.
Northern 25 - 50 mm below average.
Eastern Melbourne 50 - 100 mm below average.
North East Highlands 10 - 25 mm below average.
Far East Gippsland 50 - 100 mm below average.
South west 25 - 50 mm below average.
3 Monthly deficiencies:
In terms of the 3 monthly deficiencies, Victoria seems to be holding well thanks to some improvements during November and December but during January 2009, the gains were largely reversed.
When analysing the 12 monthly rainfall deficiencies, the deficiencies become clear. Large swathes of the state continues to suffer "Serious Rainfall deficiencies" with significant deficiencies around Melbourne and Geelong.
The web site at http://www.bom.gov.au/cgi-bin/silo/rain
provides various maps and data can be manipulated to show the above.
In south west New South, also suffering drought, the situation has also not improved:-
Southern New South Wales suffered below average rainfall and the south west suffered very much below average rainfall. The far south west had no rain recorded and the Murray Riverina averaged 5 - 10 mm.
To highlight how dry January was in these regions, Narrandera had 0.8 mm of rain which is the lowest in 39 years of records (Weatherzone and BOM 31/1/2009).
Its interesting when overlying the daily temperature plots, now available at the same website "Click on Temperature" at:-
http://www.bom.gov.au/cgi-bin/silo/rain
The Murray Darling Basin including North West Victoria, Northern Victoria, Southern New South Wales and South West New South Wales has suffered through a torrid January where:-
Maximum highest daily temperatures reached 42 to 45C where rainfall deficiencies were the highest.
Maximum anomalies of 3C above average temperature were recorded. They were recorded in the areas experiencing years of rainfall deficiencies.
In conclusion, the heat and low rainfall of January is clearly marked in the areas that has been in drought over recent years and the start of 2009 has also been dry for these regions.
Harley Pearman
-
Indian Ocean is drought culprit "SydneyMorning Herald 5/2/2009
An excellent article in the Environment Section of the Sydney Morning Herald dated 5/2/2009 provides new insight into the drought afflicting the Murray Darling Basin. Located at:-
http://www.smh.com.au/news/environment/indian-ocean-is-drought-culprit/2009/02/04...
The article suggest that droughts may be traced to the waters of the Indian Ocean that could overturn decades of weather research.
The study is showing that the cycle of El Nino and La Nina events which have long been thought to play a major role in south east Australia's weather patterns are in fact less important than the Indian Ocean.
The research is giving valuable insights into rainfall predictions for the Murray Darling Basin.
The report has found that a phenomenon known as the Indian Ocean Dipole plays a dominant role in determining temperature and rainfall in south eastern Australia.
During a negative dipole, cooler winds carry moisture in south east Australia but during a positive dipole, warmer and dryer winds limit rainfall and contribute to high temperatures. In the past three years, there have been successive positive cycles. Further, there may be evidence that positive dipoles are becoming more dominant.
The dominant role of the Indian Ocean explains why the La Nina event which usually brings rains failed to break the drought when it last occurred in 2007.
If the trends continue in which positive Indian Ocean dipoles continue, then this could spell bad news for the Murray Darling Basin.
The Murray Darling Basin has updated into quarterly advice showing the drought is worsening, toxic algae blooms are expected and water storages are well down.
This is an excellent article worth reading.
(Sydney Morning Herald, Article by Ben Cubby 5/2/2009)
Harley Pearman
-
Hi guys,
I am not likely to forget those high temps, it was 40+ for days running and topped 46 in early Feb 71. My son was born 28th Jan and a week later I was sitting in the bath with ice cubes to keep him cool, you also couldn't touch doorhandles without a towel, you would have burnt your hands.
Lansvale where we lived on the Prospect creek (most of it on the other side is parkland now), we had a sort off river breeze a lot of Fairfield and Liverpool wouldn't have gotten, temps for the area would most likely be either one of those or even Parramatta and Windsor, going back a few years most of the outer western suburbs, like most of Riverstone where paddocks.
-
Ursula,
I am not likely to forget those high temps, it was 40+ for days running and topped 46 in early Feb 71. My son was born 28th Jan and a week later I was sitting in the bath with ice cubes to keep him cool, you also couldn't touch doorhandles without a towel, you would have burnt your hands.
Check out the observations for Richmond which are the only continuous records I could find to base ourselves on:
http://www.bom.gov.au/climate/averages/tables/cw_067033_All.shtml
This highest ever temperature for January was 47.8C which occurred in the summer of 1939 and then 43.7C on the 1st February 1977. No 46C temperatures in sight and I personally would find it extremely unlikely for February to produce such extreme temperatures. If it hits 44C tomorrow, it will be a record.
Regards,
Jimmy Deguara
-
Drought and Fire here to stay with El Nino's return
More on the drought affecting inland southern New South Wales and Victoria an article prepared by Adam Morton dated 17/2/2009 in the Age (Melbourne) provides grim news for Victoria and predicts that:-
- Victoria is poised to come under a new El Nino drought is less than 3 years with the National Climate Centre expecting a new El Nino and associated drought as early as 2010 or during 2011.
- The build up to the next El Nino has begun.
- Concerns of the next drought are growing as climate scientists add their voices that climate change is being belt more rapidly than expected.
Given that Victoria has not recovered from the current drought and with the next El Nino in sight, it is grim news for southern Australia.
This is the second similar storey that I am aware off in which the next El Nino drought is being predicted for southern Australia.
http://www.theage.com.au/national/drought-and-fire-here-to-stay-with-el-ninos-return...
Harley Pearman
-
February 2009 Rainfall situation and update on drought situation
The Bureau of Meteorology latest February 2009 drought statement is found at:-
http://www.bom.gov.au/announcements/media_releases/climate/drought/20090304.shtml
Titled "A dry February For South Eastern Australia". Rather than repeat the contents of this including its maps showing the current level of drought, I will reinforce this with data obtained from:-
Murray Darling Basin Commission.
Bureau of Meteorology.
Weather Zone.
Goulburn / Murray Water Authority.
February was exceptionally dry across the state of Victoria and Southern New South Wales which ultimately led to the horrific bushfires. To highlight this, the rainfall figures for January and February at selected centres is produced below:-
Place Total rainfall for January / February 2009 Normal
Albury / Wodonga 11.4 mm 72.4 mm
Ararat 2.8 mm 73.2 mm
Bairnsdale 53.9 mm 96.2 mm
Ballarat 2 mm 82.9 mm
Bendigo 0.4 mm 62 mm
Casterton 5.6 mm 55.1 mm
Echuca 1 mm 53.5 mm
Geelong 2.6 mm 68.9 mm
Hamilton 5 mm 60 mm
Horsham 0.2 mm 47.8 mm
Kerang 0.6 mm 46.5 mm
Melbourne 3.8 mm 95.9 mm
Mt Hotham 21.4 mm 180.1 mm
Mildura 0.8 mm 41.7 mm
Portland 14 mm 62 mm
Shepparton 13.6 mm 57.7 mm
Wangaratta 28.2 mm 82.6 mm
In New South Wales (Specific to the Southern Murray Darling Basin):-
Griffith 22 mm 60 mm
Hay 1.6 mm 55 mm
Wagga Wagga 38 mm 79.2 mm
(Sources - Bureau of Meteorology although averages for the second column are sourced from Weatherzone)
Very little rainfall was recorded throughout Victoria during February with many centres recording exceptionally low totals. Swan Hill not in the above list recorded "Nil" rainfall for the same period. The media has reported that Melbourne has had its driest start to a year since 1893.
The monthly rainfall plots show only parts of Gippsland receiving any meaningful rainfall, receiving between 25 and 50 mm. All areas of the state recorded below or very much below average totals. Approximately 85% of the state recorded rainfall in the 0% to 20% normal range with a small portion of Gippsland near Bairnsdale receiving close to average falls at best.
http://www.bom.gov.au/cgi-bin/silo/rain
Numerous maps and rainfall plots can be manipulated for various locations and states at this site.
It is reported that 55% of New South Wales is still in drought with the south and west hardest hit over the long term.
The state of Victoria and southern NSW has had a tough start to 2009. The low rainfall is reflected in some water storage's being at critical low levels. Additionally some large water storage's have been checked in the affected region and water supplies are stressed again. The Goulburn / Murray Water publishes a list of water storage's and day to day storage levels that can be found at:-
http://www.g-mwater.com.au/water-resources/storage-levels
As at 2/3/09, the largest and some small storage's held:-
Can Curran Reservoir - 4,282 Megalitres or 2.91% capacity.
Dartmouth Reservoir - 863,665 Megalitres or 22% capacity.
(This dam is holding up reasonably well due to location and water is only drawn down in times of drought to maintain flows in the Murray and supplements Hume Dam during very dry periods).
Eildon Reservoir - 537,004 Megalitres or 16.11% capacity.
Hume Reservoir - 303,800 Megalitres or 10.89% capacity.
Lake Eppalock - 18,480 Megalitres or 6.07% capacity.
Tullarooh Reservoir - 3,268 Megalitres or 4.48% capacity.
Water in the Hume Dam has now been drawn down by some 10,000 megalitres over the past few days to 9.63% as at 7/3/09 to maintain water supplies further along the Murray River. Water levels in the small dams are severely stressed but water levels in the states largest reservoirs are also at low levels reflecting the low rainfall.
To highlight the persistent dry, rainfall at some dams for January and February 2009 are compared to rainfall for January and February 2008.
Dam 2008 Rainfall 2009 Rainfall
Can Curran Reservoir 22 mm 5.4 mm
Dartmouth Reservoir 126 mm 60.8 mm
Eildon Reservoir 70.8 mm 10 mm
Hume Reservoir 130.8 mm 8.8 mm
Lake Eppalock 40.4 mm 3.6 mm
Tullarooh Reservoir 12.8 mm 6.8 mm
It has been an exceptionally dry start to 2009 with rainfall well below average. The latest drought map prepared by the Bureau of Meteorology posted above shows Victoria a state in distress with severe rainfall deficiencies in some areas. The figures provided above reinforces that view.
Harley Pearman
-
To continue this topic on the ongoing drought, I found a good drought statement at this link prepared by the Murray Darling Basin Authority for February 2009:-
http://www.mdba.gov.au/system/files/DroughtUpdate_February2009.pdf
It looks specific at the remaining water resources in the reservoirs specific for the Murray Darling Basin. Such low water inflows is a serious concern. The statement concludes that urban water supplies are guaranteed for 2009/2010 despite the serious shortage of water.
I sources other articles prepared by Debra Jopson "Rain Declines by 40% over 10 years" from the Sydney Morning Herald 9/3/2009 in the Environment Section.
This one looks at a specific farmer struggling with dwindling water resources on a farm 5 km east of Howlong or 25 km west of Albury. The article describes regular dust storms. Where a decade ago, good grazing land existed but now without rain, the land is simply dust.
http://www.smh.com.au/environment/water-issues/rain-declines-40-per-cent-over-10-years-20090308-8sgw.html
Another one titled "Murray Towns are living Hand to Mouth" by the same writer, Sydney Morning Herald and dated 9/3/2009 provides a more scientific view of the crises and includes:-
- Rice production has plummeted by 93%.
- Some towns are experiencing population exodus.
- River inflows for the entire Murray River was as low as 40 Gigalitres for the month of February 2009.
- Total water storage fell to 1,170 Gigalitres (1,170,000 megalitres) in February 2009.
- The citrus industry is in trouble.
While the north and east of Australia receives its good rainfall, the situation across southern New South Wales and much of Victoria is a total contrast of extremes.
http://www.smh.com.au/environment/water-issues/murray-towns-are-living-hand-to-mouth-20090308-8sgi.html
Harley Pearman
-
- Rice production has plummeted by 93%.
Well that is some good news at least. We shouldn't be trying to grow rice along the Murray-Darling system. Cotton is a similar problem.
For that reason I refuse to buy Australian grown rice (even though I normally try to buy Australian).
-
Richary, the growing of rice in South West New South Wales was always most inappropriate and requiring very large amounts of water that is now unavailable. Such practices has created another problem called wetland salinity. The drought has effectively wiped out the rice growing industry.
The first rainfall event across the southern Murray Darling Basin in a while has produced some good but very localised rainfall. It is best described as hit and miss and many areas missed out.
In the week 7 to 13 March cumulative rainfall totals from the weather event include:-
Karpa Kora 70 mm (The best that I can find)
Junee 46 mm
Dookie 38 mm
Parkes 33 mm
Cowra 28 mm
Wagga Wagga 16 mm
Yarrawonga 14 mm
Murchison 14 mm
Mildura 13 mm
Beechworth 12 mm
Wangaratta 11 mm
Albury 8.8 mm
Griffith 0.6 mm
The figures quoted above do not include the totals from the showers and thunderstorms that occurred across eastern parts of the region 14/3/2009. Even these were hit and miss as well.
This shows the fickle nature of the rain that fell across the few days when rain fell. In no way has it broken the drought and some locales received nothing.
The rain plot for the week taken from the Bureau of Meteorology site http://www.bom.gov.au/cgi-bin/silo/rain (http://www.bom.gov.au/cgi-bin/silo/rain)
below shows this.
Harley Pearman
-
Richary, the growing of rice in South West New South Wales was always most inappropriate and requiring very large amounts of water that is now unavailable. Such practices has created another problem called wetland salinity. The drought has effectively wiped out the rice growing industry.
Hi Harley. Agreed, and the citrus production etc in places like Menindee are also probably unviable and contributing to destroying the Murray-Darling system. As well as cotton in Qld. Apart from being interested in weather I am interested in the environment. When I first moved to SA in 2000 I drove down past the Coorong Lakes to see the water up to the edge of the road. My last trip down there about 2 years ago you could hardly see the water the lakes were that low - and a lot lower now.
I have camped beside the Murray in Victoria to the sound of water pumps running all night. To visit these areas and see the damage to the river red gums etc that is being caused as they are used to a flood every so often is very depressing. I am well aware of the problems of salinity in these areas as well.
In reality the only solution is probably to dismantle all the weirs and the Hume Dam. Though I have also seen the Hume Dam full and when I went past it 18 months ago it was also hardly visible from the road.
While there is water coming down the Darling River system at the moment, I suspect very little of it will make it to the Lower Lakes.
-
Richary, Australian Geographic has been following the impact of this drought since 2003 and has been following the impacts specific to the Murray Darling Basin. Two storeys of interest include:-
The Drought (By Matthew Cawood) Edition 70 - April June 2003 (Page 92-99).
It is specific to the Murray Darling Basin and highlights what happened during the big dry of 2002/2003 including:-
Cost - $5Billion.
- Rice crop down by 70%.
- Sorghum crops down by 65%.
- Wheat crops down by 58%.
- Canola crop down by 61%.
- Cotton crop down by 66%
Sheep and cattle herds were down by a modest 9% and 3% respectively.
Most of Australia was affected and the Murray Darling Basin generally experienced rainfall as:-
- Serious deficiency.
- Lowest on record.
The matter is described again in the storey titled:-
Water by Elizabeth Ginis (Edition 77) Jan - Mar 2005 (Page 36 - 52).
It is also specific to the big dry in the Murray Darling Basin affecting cotton growing. The storey describes how cotton growing is struggling under drought conditions. In times of drought, the growing of cotton is not sustainable.
Now comes a storey in the Sydney Morning Herald dated 18/3/2009 (AAP 2009) which reinforces this:-
Sun Rice to axe 36 jobs due to drought. It is more specific to the impacts of the current drought on rice production such as:-
Only 75,000 tonnes may be harvested in 2009 compared to 19,000 tonnes in 2008.
This is down from the 1.2 million tonnes that could be harvested.
There is no reserve left in the Riverina (rice and water resources).
In 2008, that is a 99% loss of the rice crop. In 2009, if 75,000 tonnes could be harvested, then that is a 93.75% reduction in harvest from past years.
This shows some of the impacts of the big dry on agriculture production in the affected region being south west New South Wales. This is contributing to the exodus of people from the region. Richary, you are right and looking at weather models of recent days, I am not seeing follow up rains on the immediate horizon for this region.
Storeys and websites referred to are:-
www.australiangeographic.com.au (http://)
http://news.smh.com.au/breaking-news-business/sunrice-to-axe-36-jobs-due-to-drought-20090318-91it.html (http://news.smh.com.au/breaking-news-business/sunrice-to-axe-36-jobs-due-to-drought-20090318-91it.html)
Harley Pearman
-
I guess (to drift slightly off topic) it parallels the early settlers experiences in South Australia. A few good years made people think they could make a go of it in areas like the Northern Flinders, Gawler Ranges and so on. When they first settled the land seemed suitable for farming. And now if you travel north in your 4WD you see the failed attempts at farming. See references to Goyder's Line this from wikipedia:
Goyder's Line is a boundary line across South Australia corresponding to a rainfall boundary believed to indicate the edge of the area suitable for agriculture. North of Goyder's Line, the rainfall is not reliable enough, and the land is only suitable for grazing and not cropping. The line traces a distinct change in vegetation. To the south, it is composed mainly of mallee scrub whilst to the north salt-bush. In general Goyder's line represents the demarcation of a long-term rainfall average of 10 inches (254mm).
With barely 30 year's knowledge of this new country to go on, farmers needed reliable information. In 1865 George Goyder provided it. He discouraged farmers from planting crops north of his line, declaring this land suitable only for light grazing. However farmers were optimistic. 1865 was a year of bumper rains, so many ignored Goyder and headed north, starting farms and planting crops. Just a few years later many had to abandon their farms. Goyder was proved correct and the land was indeed unsuitable for crops. Many farmhouse ruins can still be seen near Goyder's line.
There have been periods of development north of the line, but invariably nature has won out. Entire towns and farms were abandoned when there was a return to longer-term average rainfall. Theline has proven remarkably accurate, an amazing feat since it was surveyed in just two months in 1865 by Goyder, then the surveyor-general of South Australia.
Goyder's line starts on the west coast near Ceduna and goes south-east across Eyre Peninsula to strike Spencer Gulf near Arno Bay. It continues from near Moonta north to Crystal Brook and Orroroo then south-east past Peterborough and Burra to the Victorian border near Pinnaroo, crossing the Murray River south of Blanchetown. Much of the land immediately north of the line is covered by saltbush. Agriculture is possible near the Murray River further upstream only because of irrigation using water drawn from the Murray.
I wonder if the development in western NSW etc followed a similar pattern. A number of years of at least average if not above average rainfall led companies and people to believe these were viable areas for planting. Then as soon as we hit a drought of any duration their whole plan comes unstuck. We are the driest continent on the planet (apart from Antarctica) so why are we trying to grow cotton, rice and citrus in an area that relies on special weather events like a cyclone coming inland as a tropical low to fill the inland rivers and make it sustainable? Of course, the fact the water then doesn't make it to the bottom of the system doesn't count. I don't know when the Murray Mouth was last open but it was prior to me moving to SA in 2001.
-
I have found another article concerning the ongoing drought in Southern New South Wales.
Due to low river flows, low rainfall and minimal runoff, a 400 km section of the Murray River River from Lake Hume 13 km upstream from Albury Wodonga to near Torrumbarry Weir near Echuca now faces a blue green algae outbreak.
Drought and low rainfall is being blamed and there are no water flows available to dilute it.
Town water supply is being guaranteed but the drought is taking its toll on the Murray River.
http://www.bordermail.com.au/news/local/news/general/noreuil-warning-as-algae-spreads/1471332.aspx (http://www.bordermail.com.au/news/local/news/general/noreuil-warning-as-algae-spreads/1471332.aspx)
The Border Mail (Kylie Dulhunty) 27/3/09 "Noreuil Warning as Algae Spreads".
Harley Pearman
-
It has been good to get the rains here over March, but the trend is steadily heading back towards the dry continuing through the autumn months and into early winter - as forecasters have been saying.
It has been dry here the last week, and I am afraid that the drought hasn't left just yet - according to Foxtel's WeatherChannel, the dam capacities in VIC have dropped to below 30% average, which is not good, especially after the ferocious Black Saturday fires tore through drough-ravaged areas back in Feb 09.
Big Pete
-
Impact of drought on Lake Hume and Murray River
The impact of the drought in southern New South Wales is graphically shown at Lake Hume which borders the state border of New South Wales and Victoria. The Hume Reservoir stood at 3.8% capacity or 115,444 megalitres as at 3/4/2009. The dam is capable of holding 3,038,000 megalitres when full in good years.
It is a dam where water is stored for irrigation use but exceptional low water storage levels are now being recorded again. A lack of rainfall is being blamed for such low water storage levels and subsequent recent issues of blue green algae blooms. Still 10,800 megalitres is being released from the dam daily to maintain some flow along the Murray River and hence water storage levels will continue to fall.
However, up to 2,000 megalitres a day will now be released from Dartmouth Dam to maintain some water in the dam and the system but there is still a deficit of 8,800 megalitres.
The region surrounding Lake Hume has had between 30 and 40 mm of rain this year (1st January to 31 March 2009) which is very dry with rainfalls well below average for the start of the year and significantly less than for the same period in 2008.
Due to drought in 2007, Lake Hume fell to 2.3% capacity.
The low water storage's is blamed on lack of rainfall in the region and upper catchments which provides another view of the drought gripping southern inland New South Wales.
http://www.bordermail.com.au/news/local/news/general/lake-holds-less-than-4/147765... (http://www.bordermail.com.au/news/local/news/general/lake-holds-less-than-4/147765...) (Dated 3/4/09)
As at 31 March 2009, rainfall has started to occur in parts of Victoria and inland New South Wales but other areas continue to miss out. Unfortunately the region surrounding Lake Hume is just one of those regions that has been missing out on good soaking rains.
Harley Pearman
-
March rainfall situation for Victoria and Southern New South Wales
Rainfall deficiencies continue for much of the area affected by drought. Rain occurred over all areas of the state however it has not removed the deficiencies. The data provided below is derived from:-
Goulburn Murray Water (Victoria).
Murray Darling Basin Authority.
Bureau of Meteorology.
Weatherzone.
All parts of Victoria had rainfall however typically, areas north of the Great Dividing Range experienced lighter falls typically 10-25 mm being common. However areas adjacent to the Great Dividing range had higher totals of between 25 and 50 mm.
East of Melbourne, some good falls occurred with 50 to 100 mm occurring.
Gippsland had between 10 and 50 mm.
The South west of the state had falls between of 25 and 50 mm.
While some areas in south west New South had some welcome falls, southern New South Wales continues to struggle with 10-25 mm being common with some areas getting 5 to 10 mm for the month.
The latest drought map is provided below. It is concluded that the rains that fell during March has not improved the drought situation.
http://www.bom.gov.au/cgi-bin/silo/rain (http://www.bom.gov.au/cgi-bin/silo/rain)
Southern New South Wales is now suffering "Serious to Severe Rainfall Deficiency.
The Highlands of North East Victoria is satisfactory.
The North West of Victoria continues to suffer "Severe Rainfall Deficiency".
Melbourne continues to suffer "Severe deficiency".
Gippsland continues to suffer from "Serious to Severe Rainfall Deficiency".
Note:- This does not include the rain and thunderstorms that fell on 3/4/2009 as the cut off date for this information is 31/3/2009.
To highlight the ongoing dry, the rainfall tally for the 21 selected centres similar to the February statement is provided below. It shows a state suffering water stress and rainfalls that are well below the norm.
Place Name Rainfall for Jan to end of March Normal Rainfall
Albury-Wodonga 35.4 mm 93.6 mm
Ararat 27.2 mm 104.8 mm
Bairnsdale 65.8 mm 138.3 mm
Ballarat 43.2 mm 125.4 mm
Bendigo 27.2 mm 82.8 mm
Casterton 43 mm 91.7 mm
Echuca 17.6 mm 83.9 mm
Geelong 37.8 mm 100 mm
Hamilton 34 mm 94.3 mm
Horsham 14.2 mm 70.7 mm
Kerang 9.8 mm 73.3 mm
Melbourne 51.4 mm 146 mm
Mt Hotham 138.6 mm 241.8 mm
Mildura 24.2 mm 59.8 mm
Portland 54.4 mm 95.3 mm
Shepparton 34.6 mm 72.4 mm
Wangaratta 50.4 mm 113.4 mm
Warrnambool 47.8 mm 98.2 mm
New South Wales
Griffith 28.8 mm 94.3 mm
Hay 35.3 mm 83.9 mm
Wagga Wagga 51.4 mm 119.9 mm
The table shows that not one selected urban centre in the drought affected area has recorded anywhere near adequate rainfall for the first three months of 2009.
The figures have been obtained from the weather stations via Weatherzone (March 2009).
The low rainfall continues to be reflected in dam levels which reinforces a state under water stress. The dams selected are the same as those used for the February statement:-
Cairn Curren Reservoir - 2.29% capacity and holding 3,369 megalitres.
Dartmouth Reservoir - 21.71% capacity and holding 848,159 megalitres.
Eildon Dam - 13.09% capacity and holding 436,542 megalitres.
Hume Dam - 3.57% capacity and holding 108,582 megalitres.
Lake Eppalock - 5.94% capacity and holding 18,087 megalitres.
Tullaroop - 4.17% capacity and holding 3,042 megalitres.
The stress on some catchments and systems is significant, especially along the Murray River.
(Figures are quoted from Goulburn Murray Water 4/4/2009 - Storage Catchments).
http://www.g-mwater.com.au/water-resources/storage-levels (http://www.g-mwater.com.au/water-resources/storage-levels)
Rainfall at the selected weather stations at the dam sites for 2009 (1 January to 31 March 2009) shows the water stress that is occurring.
Dam site Rainfall for 2009 Rainfall for same period in 2008
Cairn Curran Reservoir 23.6 mm 50 mm
Dartmouth Reservoir 85.8 mm 173.8 mm
Eildon Dam 60.4 mm 103 mm
Hume Dam 44.4 mm 156.8 mm
Lake Eppalock 28.6 mm 48.8 mm
Tullaroop 24.4 mm 30.2 mm
The drought statement map provided below reinforces the above and shows that Southern New South Wales and most of Victoria continuing to receive below average rains and experiencing drought conditions.
Harley Pearman
-
Likely April to June rainfall for the drought affected regions
I have been looking at possible rainfall trends for the drought affected region April to June 2009.
The models prepared by the Bureau of Meteorology paints a grim picture for South West New South Wales and much of western Victoria.
Models are showing that the chance of above median rainfall is less than 40% over south west New South Wales and Victoria except East Gippsland. The chances of exceeding above median rainfall in western Victoria drops to 35%. It means that drier than normal conditions have a 60% to 75% chance of occurring across the broad region.
The rainfall outlook confidence and associated rainfall map prognosis is available at:-
http://www.bom.gov.au/climate/ahead/rain_ahead.shtml (http://www.bom.gov.au/climate/ahead/rain_ahead.shtml)
Heading titled "Mixed June quarter rainfall odds in the east and south" prepared by the Bureau of Meteorology dated 24 March 2009.
The Bureau of Meteorology site 'Water and the Land" contains an interactive feature on likely rainfall patterns and rainfall models up to 3 months in advance at:-
http://www.bom.gov.au/watl/rainfall/exceedance.html (http://www.bom.gov.au/watl/rainfall/exceedance.html)
For Rainfall outlook. This is relatively new on the website.
Go to Rainfall, then click on 3 months Outlook.
Then click on any of the Australian states.
It is possible to view various rainfall scenarios by clicking on the icons. Specific to Victoria and southern New South, the model rainfall plot - April to June has been generated from this (Below). The plot suggests that some rainfall will return to southern Victoria but north of the Great Dividing Range, the plot suggests that rainfalls will be light for the next three months and hence the drought continuing.
The Sydney Morning Herald dated 8 April 2009 ran a very good article titled 'Murray Flows Lowest in a Century" by Debra Jopson (8/4/2009) at:-
http://www.smh.com.au/environment/water-issues/murray-flows-lowest-in-a-century-2... (http://www.smh.com.au/environment/water-issues/murray-flows-lowest-in-a-century-2...)
It reinforces the low water levels in the stricken Murray River that are occurring. Critical to the article are the following points:-
- The amount of water flowing in the Murray January to March quarter is the lowest in 117 years since records were kept.
- The lowest flows on record have been identified.
- More dry weather is predicted for the next three months and hence the drought looks set to continue.
- The total water storage of the entire system is now down to 11%.
The desperately needed rainfall does not appear to be on the horizon and hence the water situation is not likely to improve.
The possible April to June rainfall plot for Victoria and southern New South Wales is below.
Harley Pearman
-
Drought worsens in Southern Murray Darling Basin:
I found this storey in Weatherzone 17/4/2009 relevant to the ongoing dry in the southern Murray Darling Basin:-
"Drought Worsens in Southern Murray Darling Basin".
It is stated that South West New South Wales has completely missed out on the recent rainfall and some places are struggling through one of the driest starts to a year on record. There are towns that have received 10 mm of rain so far for 2009 being well short of the normal average. The towns of Deniliquin and Renmark have been singled out in which it is stated that Deniliquin has had 10 mm for 2009 and Renmark has had 2 mm for 2009 up to 17/4/2009.
The extreme dry follows consistent below average rains since 2001.
http://www.weatherzone.com.au/news/drought-worsens-in-southern-murray-darling-basin/11707 (http://www.weatherzone.com.au/news/drought-worsens-in-southern-murray-darling-basin/11707)
Actual 2009 rainfalls for the places in the above mentioned storey up to 17/4/2009 provides a sobering thought as to how dry it is here. Figures are taken from the local weather stations - Weatherzone 17/4/2009.
Renmark - 2.4 mm on 2 days. Average rainfall to the end of April is 54.6 mm.
Deniliquin - 10.1 mm on 11 days. Average rainfall to the end of April is 125.5 mm over 16.6 days.
Currently, average rainfall for the 2 centres is a fraction of what it should be under normal conditions.
Harley Pearman
-
April rains ease dry conditions in North East Victoria
Rains during the month of April has helped to ease serious rainfall deficiencies especially in North East Victoria however, deficiencies across much of the state remains. In particular:-
3 Month drought statement - April rainfall has eliminated serious deficiencies except for 2 areas being East Gippsland and an area North West of Melbourne and Geelong but South of Ballarat.
6 Month drought statement - The whole of Victoria appears satisfactory.
9 Month drought statement - Rainfall deficiencies exist around Melbourne and North West to Ballarat towards the South Australian border and a small area is suffering "Severe deficiency" being North West of Geelong with the rest of Victoria being satisfactory.
12 Month drought statement - Long term deficiencies still exist around Melbourne including severe deficiencies East and West of Melbourne including Geelong and Ballarat.
The plots provided below from the Bureau of Meteorology "Water and the Land" site show the 3 month drought statement from February to the end of April 2009 as well as the 3 monthly rainfall plot for the state as well as for Southern and South West New South Wales. The rainfall plot is for 1 February to 30 April 2009.
Sites and information used to complie this are derived from:-
Bureau of Meteorology.
Weatherzone.
Goulburn Murray Water.
Murray Darling Basin Authority.
http://www.g-mwater.com.au/water-resources/rainfall.asp (http://www.g-mwater.com.au/water-resources/rainfall.asp)
http://www.bom.gov.au/cgi-bin/silo/rain_maps.cgi (http://www.bom.gov.au/cgi-bin/silo/rain_maps.cgi)
In addition to the maps and plots provided below, actual rainfall and normal rainfall from 1 January to April 30 2009 for the selected towns and cities is provided below from Weatherzone:-
Town/ city Rainfall Jan-April Normal Rainfall
Albury-Wodonga 120.2 mm on 21 days 126 mm (Almost average)
Ararat 56.4 mm on 25 days 148.3 mm (Rainfall is low)
Ballarat 76.2 mm on 31 days 178 mm (Rainfall is low)
Bendigo 49.8 mm on 15 days 108.6 mm (Below average)
Casterton 95.4 mm on 44 days 135.3 mm (Below average)
Echuca 38.2 mm on 13 days 116.6 mm (Rainfall is low)
Geelong 77 mm on 33 days 149.8 mm (Rainfall is low)
Hamilton 70.4 mm on 38 days 131.9 mm (Rainfall is low)
Horsham 34.4 mm on 14 days 99.7 mm (Rainfall is low)
Kerang 36.6 mm on 11 days 98.6 mm (Rainfall is low)
Melbourne 90.6 mm on 31 days 203.9 mm (Less than half)
Mt Hotham 285 mm on 36 days 321.1 mm (Near average)
Mildura 45.2 mm on 13 days 78 mm (Below average)
Portland 120 mm on 35 days 136 mm (Near average)
Shepparton 64 mm on 18 days 106.9 mm (Below average)
Wangaratta 90.6 mm on 19 days 155.3 mm (Below average)
Warrnambool 147.6 mm on 42 days 143 mm (Slightly above)
Southern inland New South Wales
Griffith 50.2 mm on 13 days 123.3 mm (Less than half)
Hay 68.1 mm on 14 days 112.1 mm (Low rainfall)
Wagga Wagga 83.6 mm on 15 days 161.6 mm (51.7% to date)
Hence during the month of April, all areas of Victoria received some rain but in areas away from North East Victoria and parts of the South West, the amounts that fell did not remove the longer term deficits. Some areas continue to fare poorly.
As shown at the selected dams below, the 1 January to 30 April 2009 rainfall is provided as well as the 1 January to 30 April 2008 rainfall to show a comparison.
Dam site Dam levels as at 2 May 09 2009 Rainfall 2008 Rainfall
Cairn Curren Reservoir 1.89% 49.6 mm 58.6 mm
Dartmouth Reservoir 20.85% 194.6 mm 219 mm
Eildon Reservoir 12.18% 135 mm 125.4 mm
Hume Dam 3.12% 130.6 mm 175.4 mm
Lake Eppalock 5.98% 50.6 mm 59 mm
Tullaroop 3.97% 52.2 mm 35.8 mm
During April 2009, the selected dam sites experienced in descending order 26 mm, 109 mm, 74.6 mm, 92.4 mm, 22 mm and 27.8 mm of rainfall. Generally areas away from North East Victoria did not experience solid rainfall.
Further the capacity of the Hume Reservoir fell to 2.7% during April and at 2 May 2009, the capacity had risen barely to 3.12% or 94,791 megalitres indicating that minor runoff or inflows may have occurred from rainfall falling further upstream. As indicated by the Murray Darling Basin Authority, there are low flows from Dartmouth Reservoir because water needs to be retained for next summer.
All parts of the state received rainfall during April however it is noted that:-
- North east Victoria and especially the Upper North East received between 100 and 200 mm.
- Adjacent hills and ranges in the same general area receiving from 50 to 100 mm.
- East Gippsland receiving 50-100 mm but some areas receiving 25-50 mm.
- Northern country away from the highlands receiving 25-50 mm.
- South West receiving 50-100 mm.
- Wilson's Promontory receiving 100 to 200 mm.
- Western areas receiving scattered falls of between 25 and 50 mm but 10-25 mm elsewhere.
- North West receiving 10-25 mm.
3 Monthly anomalies 1 February to April 2009
Following good April rainfalls, North East Victoria now has rainfalls close to average or between 0 and 25 mm below average.
Elsewhere it is less promising:-
- Northern Country continues to experience rainfalls 25 to 50 mm below average.
- Melbourne is experiencing rainfall that is at least 100 mm below average.
- East Gippsland is experiencing rainfall that is 50 to 100 mm below average.
- There are portions of East Gippsland suffering large rainfall deficits of between 100 and 200 mm below average.
- The South West is near satisfactory with rainfalls close to average or between 0 and 25 mm below average.
- The western areas is experiencing rainfalls 25 to 50 mm below average.
- The North West is experiencing rainfalls 25 to 50 mm below average.
- The far North West close to the South Australia border has rainfalls of between 0 and 25 mm below average indicating a slightly improved condition here.
In conclusion, there has been some recovery during the month especially across North East Victoria and adjacent areas as well as some improvements in some far western and south western areas. However, for the majority of the state, the rainfall deficits are still noticeable to significant.
Harley Pearman
-
NSW Sustainable Development Conference - Discussion of the ongoing drought
On Tuesday and Wednesday 12 and 13 May 2009, I attended the New South Wales Sustainable Development Conference at Darling Harbour. The morning topic was on "Water issues" with extensive reference to the drought affecting the Murray Darling Basin.
In particular after the fifth speech given by Ian Blair, Director of Quadraco Asia Pacific, I had a discussion with him on what the future represents for the Murray Darling Basin given the critical water issues faced and the drought.
The speech by Dr Fraser Mäc Leod (First speech dealing with rainfall patterns) he describes the situation as extremely serious. For example in 2006/2007, rainfall in many areas of the basin especially the south east was the lowest on record.
He describes how a 13% drop in rainfall has lead to a 39% reduction in runoff into rivers and streams. He also describes that we are into the third year with record low inflows into rivers and dams. In good years maximum storage levels in dams in the basin could be as high as 30.076 GL (Gigalitres). However with the drought and lower rainfall patterns the system is under very serious stress and new plans and initiates are required to address drought, declining rainfall, even climate change and water use. It is a difficult matter to solve given the pressures involved.
The new plans to manage declining water supplies will be tough to produce in an era where recent drought has pushed system into "Uncharted territory".
Following the speech by Chris Davies (Third speech), the Mayor of Leeton in the Riverina of New South Wales described the drought as destroying the fabric of communities in his area. For example, the rice industry has effectively been wiped out in the area and there is depopulation occurring from smaller towns to larger centres.
Ian Blair, the fifth speaker prodcued data showing some areas in the basin in southern New South Wales experiencing a decline in rainfall of 180 millimetres since the early 1990s.
I was fortunate enough to speak to Ian after his speech and asked him a question as to what the future represents for the basin given:-
- Climate change.
- Dwindling water resources.
- Low dam levels (I provided an example of Hume Dam being a little over 3% capacity of recent times).
- On going drought.
- Depopulation of small country centres.
He described to me how agriculture will be forced to adapt or die out and some forms of agriculture such as rice growing may never recover. Small scale intensive agriculture that has low water use could survive in this new environment but generally the level of agriculture seen in the past is unlikely to be seen again.
Harley Pearman
-
Winter rainfall predictions for southern New South Wales and Victoria
I have been looking at likely rainfall scenarios across inland Southern New South Wales and Victoria for the period June to August 2009 and evidence is emerging that a new El Nino weather pattern may be on its way from August onwards.
Rainfall plots suggests the following:-
- The chance of exceeding median rainfall June to August sits between 40% and 45% across a swathe of southern New South Wales and most of Victoria except East Gippsland where it sits between 45% and 50%.
- Portions of Southern Victoria is situated in the 35% to 40% range of exceeding its median rainfall during the period.
Models seem to suggest a general drying trend starting to occur especially over the western areas of Victoria. Additionally:-
- The majority of the state of Victoria has a 75% chance of receiving at least 100 mm of rain except the NW areas close to the Murray River.
- The mountainous areas of North East Victoria as well as pockets of the south west coast and Wilson's Promontory has a 75% chance of receiving up to 200 mm of rain.
- Pockets of North East Victoria has a 65% chance of receiving up to 300 mm of rain but that is limited to the mountainous areas.
The website http://www.bom.gov.au/jsp/watl/rainfall/pme.jsp (http://www.bom.gov.au/jsp/watl/rainfall/pme.jsp) and http://www.bom.gov.au/climate/ahead/rain_ahead.shtml (http://www.bom.gov.au/climate/ahead/rain_ahead.shtml) has been used for this summary.
The attached plot below shows the regions that has a 75% chance of receiving up to 200 mm of rain for the period. The details can be found at the Bureau of Meteorology Website under the heading "Water and the Land". Click on "Rainfall". Then click on "3 Month Outlook". Then click "Chance of at Least".
Plots can be generated for various scenarios. Generally most of the state stands a good chance of receiving falls approaching 100 mm during the three month period but beyond that, the areas that may receive a greater amount declines.
Possible new El Nino From August 2009:
The ENSO status at 21 May 2009 raises serious concerns regarding the next El Nino phase weather pattern. Critical points are:-
- Possible trend towards the next El Nino but requiring monitoring.
- The Equatorial Pacific Ocean has warmed.
- The SOI in April was plus 9 however during May it plunged to negative 7 (May 21 reading).
- Trade winds are weaker.
- The cloud cover at the International Date Line is not showing much change.
The CSIRO has introduced an experimental computer model still being tested called POAMA - Predictive Ocean Atmosphere Model for Australia.
The models are available for viewing and plots can be generated. From POAMA, I was looking at the SST plot forecast 28 April to 27 May 2009 which was showing the following:-
- The Humbolt Current off Ecuador had showed a warming trend of 1.5C to 2.5C and a belt of warm water started to stretch west across the Equator region of the Pacific Ocean.
- Water temperatures off NE Australia are stable but a cooler body of water is evident well off the coast of NE Australia.
July 2009:- A water temperature plot can be generated for July which was showing the warming trend extending further west across the Pacific Ocean.
December 2009:- A water temperature plot can be generated for December which appears to be the limit of the models. The models show extensive warming of waters in the Pacific Ocean and Indian Ocean.
The POAMA model while experimental is showing El Nino conditions later in 2009 especially from spring.
The POAMA model is a new forecast system based on a coupled ocean / atmosphere model and ocean atmosphere land observation assimilation system. It is still being tested and its website is:-
http://poama.bom.gov.au/ (http://poama.bom.gov.au/)
The POAMA model shows:-
2-4 months - Warm.
5-7 months - Warm.
The NCEP model shows:-
2-4 months - Warm.
5-7 months - Warm.
Generally, most weather models seem to show a warming trend although the UK Model shows neutral conditions for the 2-4 month period and N/A for the 5-7 period.
The SOI is currently neutral but a warming phase is starting to show with SSTs around 0.5C warmer. Additionally the May 27 SOI shows a further drop to - 11.
The plot for the cloud cover at the International Date Line does not show much change at this stage.
Numerous model plots can be generated from POAMA. To access the POAMA models and the cloud cover plot for the International Date Line, the following website can be used http://www.bom.gov.au/climate/ahead/ENSO-summary.shtml (http://www.bom.gov.au/climate/ahead/ENSO-summary.shtml)
Follow the links provided.
El Nino events are associated with drier than normal conditions and or drought conditions over Eastern Australia. Southern New South Wales and most of Victoria has not recovered from the previous drought and areas of long term serious to severe water deficiencies and rainfall deficiencies remain. A new El Nino phase if it does eventuate later this year is a cause of concern. This too will be discussed in this thread as time progresses.
Harley Pearman
-
Harley,
I have been noticing the long-range rainfall forecast on Weatherzone(.com.au) is prediciting steep negative values for Spring 09 in the Central district of VIC (incl Melbourne metro & Suburban areas). This would also suggest El-Nino is on its way back again - which does not pose well for rainfall in VIC come spring, when rainfall here is normally at its peak. Looks like dryness is yet to depart here.
Big Pete
-
- Pockets of North East Victoria has a 65% chance of receiving up to 300 mm of rain but that is limited to the mountainous areas.
I must admit that a large portion of that rainfall will fall as Snow on those areas...
Big Pete
-
May 2009 Rainfall and Drought Report with reference to Melbourne's Water Supply
A single rain event across Western Victoria provided some short term relief from the dry however many areas of the state continued to experience significant rainfall deficiencies. In particular:-
- The 3 month drought statement shows rainfall deficiencies confined to an area north west of Geelong and a portion of Gippsland (East Gippsland). The short term plots do not show the drought too well and suggests that Victoria is mostly satisfactory in the short run.
- The 6 month drought statement shows a different storey with severe rainfall deficiencies covering Eastern Melbourne including an area classified as "Lowest on record" for an area north east of the city in the Dandenong Ranges and severe deficiencies affecting East Gippsland, Geelong and region and "Serious"deficiencies covering the rest of southern Victoria.
- The 9 month drought statement shows Melbourne suffering "Severe deficiencies" including "lowest on record" east and west of Melbourne. Severe rainfall deficiencies cover Southern Victoria including Ballarat and Bendigo as well as in Western Victoria.
The 12 month plot is reproduced below. The 12 month plot from 1 June 2008 to 31 May 2009 shows the drought impact much better. There are "Severe deficiencies" around Melbourne and Geelong, south coast of NSW close to the Victorian border and western Victoria. There are also "Serious rainfall deficiencies" stretching through southern New South Wales including Albury - Wodonga region and Wagga Wagga region.
Given the situation in Melbourne, reference is made to Melbourne's water supply. As at 3 June 2009 Melbourne's water supply was at 26.1% capacity and the Thompson Reservoir was down to 178,783 megalitres or 16.7% capacity.
The information provided in this statement is derived from data from:-
Bureau of Meteorology.
Weatherzone.
Goulburn Murray Water.
Melbourne Water.
The 12 month drought plot is generated from http://www.bom.gov.au/cgi-bin/silo/rain_maps.cgi (http://www.bom.gov.au/cgi-bin/silo/rain_maps.cgi)
Rainfall in the selected regional centres from 1 January to 31 May 2009 are below:-
Albury Wodonga
127 mm on 24 days (Normal is 179.6 mm on 26.3 days). Only 6.8 mm fell in May compared to its long term average of 52 mm. This was very close to the 2005 figure of 3.2 mm which is the lowest on record. May was extremely dry here.
Ararat
110 mm on 38 days (Normal is 202 mm on 44.8 days). This is 54.4% of the average.
Bairnsdale
110.6 mm on 42 days (Normal is 250.7 mm on 50 days). This is 43.8% of the average.
Ballarat
96 mm on 44 days (Normal is 243.5 mm on 53.2 days). This is 39.4% of the average.
Bendigo
69.8 mm on 21 days (Normal is 155.3 mm on 32.4 days). This is 44.9% of the average.
Casterton
162.8 mm on 72 days (Normal is 195.5 mm on 52.9 days). Almost average.
Echuca
51.4 mm on 17 days (Normal is 157.7 mm on 26.3 days). This is just 32.9% of the average.
Geelong
97.2 mm on 46 days (Normal is 200.8 mm on 45.4 days). This just under half its normal rain for the 5 months.
Hamilton
124.2 mm on 60 days (Normal is 180.4 mm on 54.8 days). Hamilton received 54.2 mm of rain during May which was above its normal average of 48.5 mm.
Horsham
98.4 mm on 27 days (Normal is 142.5 mm on 27.6 days).
Kerang
48.4 mm on 16 days (Normal is 134.8 mm on 22.3 days). Kerang has received 35.9% of its normal rain to date.
Melbourne
Melbourne is singled out receiving 101.4 mm on 40 days (Normal is 260.3 mm). This is 158.9 mm below average. This is 38.9% of its normal rainfall.
Mt Hotham
382.9 mm on 42 days (Normal is 449.4 mm on 54.3 days). This is 85.2% of average.
Mildura
55.8 mm on 22 days (Normal is 103.6 mm on 21.3 days). This is 53.8% of average.
Portland
159.4 mm on 56 days (Normal is 195 mm on 58.4 days).
Shepparton
73.6 mm on 23 days (Normal is 139.2 mm on 26.7 days). This is 52.8% of the average.
Wangaratta
106.8 mm on 23 days (Normal is 220.4 mm on 32.1 days). This is 48.4% of the average.
Warrnambool
210.4 mm on 62 days (Normal is 196.8 mm on 59.8 days). Rainfall is slightly above average here.
South West New South Wales
Griffith
54.2 mm on 15 days (Normal is 159.8 mm on 22.8 days). This is 33.9% of the average. Only 4 mm fell in May compared to its May average of 36.5 mm.
Hay
79.5 mm on 17 days (Normal is 147.1 mm on 21.5 days). This is 54% of the average to date.
Wagga Wagga
91.2 mm on 18 days (Normal is 213.7 mm on 31.8 days). This is 42.6% of the average to date.
Rainfall and water capacity at the chosen dam sites are:-
Dam site Capacity Rainfall to end of 31 May 2009 Rainfall for same period 2008
Cairn Curren 1.83% 64.8 mm 90.6 mm
Dartmouth 21.15% 217.6 mm 249.8 mm
Hume Dam 6.60% 139 mm 199.2 mm
Lake Eildon 12.23% 162 mm 178.8 mm
Lake Eppalock 5.98% 66.8 mm 83.7 mm
Tullaroop 3.84% 69 mm 72.4 mm
Lake Mokoan in Northern Victoria has dried up recording a capacity of 0%.
The state of Victoria is not well placed to endure any El Nino weather event should it emerge later this year.
There was a single rain event across parts of Western Victoria during May but most areas missed out. In particular:-
- Very much below average rains prevailed around Albury Wodonga region, Gippsland as well as Melbourne (In Decile 1).
- Some western areas reached average rainfalls.
- The rest of the state recorded below average rains (In Decile 2 and 3).
The 12 month drought plot for the state is attached below as discussed earlier.
Harley Pearman
-
...The 6 month drought statement shows a different storey with severe rainfall deficiencies covering Eastern Melbourne including an area classified as "Lowest on record" for an area north east of the city in the Dandenong Ranges and severe deficiencies affecting East Gippsland, Geelong and region and "Serious"deficiencies covering the rest of southern Victoria...
Harley - I think you found my area - where I live is in the Dandenong Ranges area (to the western edge of it), and our rainfall here is about 39% of the norm for this time of the year - also I believe the dam levels are now in the trigger stage for Stage 5 water restrictions - but this government won't go there, coz it will cost too many jobs and close too many small businesses.
Big Pete
-
Harley,
He described to me how agriculture will be forced to adapt or die out and some forms of agriculture such as rice growing may never recover. Small scale intensive agriculture that has low water use could survive in this new environment but generally the level of agriculture seen in the past is unlikely to be seen again.
Perhaps some farmers will be not survive but to suggest that some forms of agriculture will not recover or that we may never see the level of agriculture seen in the past is pretty brave assumption given that this was a very severe drought. Just remember, besides the drought, international market pricing and subsidies on agricultural products also forced a change in farming techniques as well as types of cultivation. Let alone the impact of greedy banks lending out ample funds and the claiming farms in return have not assisted either! The main impacts of this prelonged and widespread drought were lack of water from an irrigation purpose with increases in salinity another major concern. If rainfall and snow melt in the Snowy Mountains returned to normal or even above average, wouldn't the MIA ( Murrimbidgee Irrigation Area ) have access to plentiful supplies of water remembering that this region without irrigation could not sustain such rich agriculture perhaps even in some better years.
Ian Blair, the fifth speaker prodcued data showing some areas in the basin in southern New South Wales experiencing a decline in rainfall of 180 millimetres since the early 1990s.
I get the impression this is pushing a further message about climate change or global warming - I probably would prefer spending money on growing rice than for some person to earn money travelling around the world presenting at conferences based on the assumption in this statement. Isn't that the definition of a drought and are we suggesting here the drought will NOT break at all? Even if it were to recover partially, even one a couple of good seasons can make one hell of a difference for farmers.
Regards,
Jimmy Deguara
-
A return to good rains would make a big difference. The speaker who gave the lecture is the Director of Quadraco Asia Pacific Pty Ltd and is based in Victoria. His background is farming and sustainability especially in relation to water conservation, power, labour and food production.
The issues of water allocation and use, drought, waste and its availability for the Murray Darling Basin were addressed by other speakers. In particular, the drought has forced a rethink on water use. The National Water Initiative has been established to address water needs. The Murray Darling Basin Authority should have a water plan by 2011 but dealing with over allocation and overuse is a critical issue and a challenge. Given the current drought, the Basin is in trouble but the National Water Initiative has helped to alleviate some of the issues. However the speaker Chris Davies did mention that we have no idea where we are going with our water (Murray Darling Basin) and we are in uncharted territory due to the drought. The Authority is trying to manage the drought using the best scientific knowledge but it is a challenge.
Latest SOI Trends:
Looking at the latest trends and models via the POAMA "Predictive Ocean Atmosphere Model for Australia" which can be accessed via the Bureau of Meteorology website or via http://poama.bom.gov.au/ (http://poama.bom.gov.au/) it shows:-
July 2009:-Warm body of water across the equatorial region of the Pacific stretching from South America towards Papua New Guinea in which the waters are between 0.5C and 1.5C above the norm. Warm waters still off Ecuador. The waters around Australia are at average temperatures.
August 2009:- Warm body of water across the equatorial Pacific 0.5C to 2.5C above the norm increasing in area.
September 2009:- Similar pattern to August.
October and November 2009:- Similar pattern to September.
December 2009:- Some warming of waters off Eastern Australia between Sydney and Brisbane is suggested in the order of 0.5C to 1.5C above the norm.
January 2010:- Significant warming of waters of Australia's east and west coast suggested in the order of 0.5C to 1.5C.
The trend towards an El Nino drought is still suggested but more data is required.
Looking at the latest rainfall expectations (July to September 2009) it is suggested that:-
- The whole of western New South Wales and southern New South Wales and much of Victoria only has a 40 to 45% chance of reaching average rainfall.
- Parts of western Victoria has only a 35% to 40% chance of reaching average rainfall.
While June 2009 has seen some useful rains, indications and models are suggesting drier conditions to return. Full details at http://www.bom.gov.au/climate/ahead/rain_ahead.shtml (http://www.bom.gov.au/climate/ahead/rain_ahead.shtml)
In particular when looking at the "Chances of rain - 75% Chance" July to September 2009 generated at the Bureau of Meteorology "Land and Water" site, the following is noted.
Victoria:
Northern Victoria 50 to 100 mm.
Central Victoria 100 to 200 mm.
North East Highlands 200 to 300 mm.
Gippsland 100 to 200 mm.
New South Wales:
The model suggest some inland regions will be relatively dry.
South West Slopes being the hills - 100 to 200 mm.
Southern New South Wales away from the hills - 50 to 100 mm.
Far South West - 25 to 50 mm.
The rainfall contour plot for this is attached below.
Harley Pearman
-
June 2009 rainfall data for Southern NSW and Victoria (With special attention to the dry afflicting Melbourne)
June 2009 saw average rainfalls to slightly above average rainfalls occur over large areas of Northern Victoria while southern Victoria largely missed out. In particular, Melbourne has experienced it's driest 6 months on record (Bureau of Meteorology 2009) and water supplies continue to decline for this city. Rainfall deficits vary in size and scale and all but one regional centre or rural centre in the case study continues to experience a rainfall deficit.
Rainfalls for 1 January 2009 to 30 June 2009
Urban centre Rainfall and days Normal rainfall and days Deficit or surplus
Albury Wodonga 198 mm on 41 days 252.9 mm on 41 days Minus 54.7 mm
Ararat 169.8 mm on 60 days 259.4 mm on 61 days Minus 90 mm
Bairnsdale 128.6 mm on 55 days 303 mm on 63.2 days Minus 175 mm
Ballarat 154.6 mm on 66 days 307 mm on 70.9 days Minus 152.4 mm
Bendigo 124 mm on 45 days 208.9 mm on 44.3 days Minus 84.9 mm
Casterton 211 mm on 95 days 264.4 mm on 70.7 mm Minus 53 mm
Echuca 98.4 mm on 38 days 200.7 mm on 36.6 days Minus 102 mm
Geelong 121.8 mm on 65 days 245.8 mm on 60.5 days Minus 124 mm
Hamilton 173 mm on 84 days 249.1 mm on 74.8 days Minus 76.1 mm
Horsham 154.6 mm on 45 days 187.1 mm on 39.1 days Minus 33 mm
Kerang 89.6 mm on 30 days 170.7 mm on 31 days Minus 81.1 mm
Melbourne 126.2 mm on 50 days 309.7 mm on 64.6 days Minus 183.5 mm
Mt Hotham 485.4 mm on 59 days 602.5 mm on 68.4 days Minus 117.1 mm
Mildura 91.4 mm on 32 days 126.8 mm on 29.1 days Minus 35.4 mm
Portland 235.4 mm on 73 days 288.7 mm on 78 days Minus 53.3 mm
Shepparton 122.4 mm on 42 days 176.5 mm on 37.8 days Minus 54.1 mm
Wangaratta 173.4 mm on 44 days 297 mm on 46 days Minus 123.6 mm
Warrnambool 346 mm on 83 days 273.6 mm on 78.3 days Plus 72.4 mm
In Victoria Warrnambool is the only centre in the case study that has received above average rains for the first 6 months of 2009. All other centres are experiencing a continued rainfall deficit and a few are experiencing a significant deficit such as Bairnsdale, Echuca, Melbourne and Wangaratta. It is noted that all the centres are receiving the normal number of rainy days but the quantities that are occurring are below average.
Southern and South West New South Wales
Griffith 129 mm on 30 days 193.6 mm on 30.3 days Minus 64 mm
Hay 159.1 mm on 32 days 183.1 mm on 29.5 days Minus 24 mm
Wagga Wagga 141.4 mm on 36 days 264 mm on 43.3 days Minus 122.6 mm
The data for June 2009 is obtained from accessing the various weather stations via Weatherzone 3/7/2009.
Dams Percentage capacity at 4 July 2009 Percentage capacity at same time 2008
Cairn Curren 1.81% 4.77%
Dartmouth 21.67% 17.93%
Eildon Dam 13.38% 14.67%
Hume Dam 11.31% 16.5%
Lake Eppalock 5.98% 6.48%
Tullaroop 3.99% 4.88%
Except for Dartmouth, the dams in the case study are holding less water now than at the same time in 2008.
Rain in the upper catchment of the Murray River seem to have provided some inflows into Hume Dam of recent weeks however this dam is holding less water now than at the same time in 2008.
Lake Mokoan in North East Victoria has totally dried up.
(Source Goulburn Murray Water - 5/7/2009)
Rainfall for the dams
Dam Rainfall 1 Jan to 30 June 2009 Rainfall 1 Jan to 30 June 2008
Cairn Curren 115.8 mm 116.8 mm (Generally no change)
Dartmouth 340.4 mm 282.4 mm (Slightly better than 2008)
Eildon 260.7 mm 223.2 mm (Slightly better than 2008)
Hume 238.4 mm 225.8 mm (Marginally better than 2008)
Lake Eppalock 127.8 mm 112.3 mm (Marginally better than 2008)
Tullaroop 129.6 mm 99.8 mm (Slightly better than 2009)
(Source Goulburn Murray Water rainfall databases 5/7/2009).
The situation for Melbourne is serious. Melbourne Water operates several dams with the largest being Thompson which when full should hold 1,068 Gigalitres of water. As at 4 July, it was holding 174,428 megalitres or 16.3% of normal capacity. Total water capacity for Melbourne now stands at 26.1%. The dry is taking a toll on Melbourne's water supply as such:-
2005 - 52.2% capacity.
2006 - 48% capacity.
2007 - 30.7% capacity.
2008 - 29.5% capacity.
2009 - 26.1% capacity.
(Overall capacity of 1,810,500 meglitres - Currently at 473,440 megalitres)
The driest first 6 months on record for Melbourne has taken its toll on Melbourne's water supply.
(Source of data - Melbourne Water 5/7/2009).
The data provided above highlights the water crises and drought as:-
3 month drought plot - Shows Melbourne and the Dandenongs suffering "Serious" to "severe rainfall deficiency" including an area North West of Melbourne also suffering the same.
6 month drought plot - Reproduced below because it provides an excellent overview of what is occurring around Melbourne including large swathes of Southern Victoria (Generated from the Bureau of Meteorology -Water and the Land site at http://www.bom.gov.au/cgi-bin/silo/rain_maps.cgi (http://www.bom.gov.au/cgi-bin/silo/rain_maps.cgi)
Severe rainfall deficiencies are affecting Melbourne including a region "Lowest on record".
9 month drought plot - Is showing "Severe rainfall deficiencies" afflicting southern Victoria with an area east and west of Melbourne experiencing "Lowest on record".
12 month drought plot - Is showing southern Victoria including Melbourne and surrounds suffering "Severe rainfall deficiencies".
It appears that enough rainfall fell across northern Victoria and southern NSW in June to eliminate the worst of the deficiencies however deficiencies still exists right across the region.
Generally June rainfall plots and anomalies for the area under review does show some short term recovery in northern areas of the state and southern New South Wales as a result of some recent rains but the south including Melbourne and region continues to experience substantial deficits.
Harley Pearman
-
El Nino for 2009 highly likely
Looking at the latest updates from the POAMA models, it is now looking more likely than not that an El Nino will emerge for the second half of 2009 and continuing into 2010.
The Bureau of Meteorology has stated that if current trends continue a reversal is unlikely. In particular:-
- Waters in the central Pacific Ocean are 1C warmer than normal.
- Sub surface water temperatures are 4C warmer than normal.
- Trade winds across the Pacific have weakened and are weaker than the norm.
- Cloud near the International Date Line has recently increased.
The SOI - Southern Oscillation Index is maintained at a monthly average of Negative 2 (June 2009). The SOI model is currently showing Minus 2. There has been a recent rise but this is expected to fall again.
The POAMA Models still show continual warming of the equatorial Pacific Ocean however the Ocean Models for December and January shows substantial warming of oceans to the north, east and west of Australia in the order from 0.5C to 2.5C above the average. The warming encircles much of Australia except the waters in the Southern Ocean.
The latest NINO Plume 3 POAMA Forecast is showing the warming anomalies becoming evident from July 2009 with a peak around December to January of 1C to 2.5C above the norm.
Looking at latest data and models, evidence is emerging of a new El Nino and a drier trend for eastern and southern Australia setting in with a peak around December 2009 to January 2010.
http://poama.bom.gov.au/ (http://poama.bom.gov.au/)
Harley Pearman
-
Good rainfalls help to ease the dry for July 2009
During the month of July, rainfall across Victoria has helped to ease the dry conditions but more rain is needed. In particular:-
- Better rainfalls have occurred with large areas of western Victoria reaching at least average rainfall for the month with some areas exceeding their average rainfalls.
- The highlands of north east Victoria also received good rainfalls/snowfalls for the month.
While much of Victoria saw an improvement, East Gippsland remained dry and areas just north of the state border also saw a dry July.
The drought / rainfall statements for July are:-
3 Month - "Severe deficiencies" still exist around Melbourne and the Dandenongs and east into Gippsland. The deficiencies are confined to south east Victoria.
6 Month - "Severe deficiencies" exist around Melbourne and Gippsland with a small area of inland East Gippsland experiencing rainfall as "Lowest on record".
9 Month - "Serious to Severe deficiencies" exist around Melbourne, Geelong and north west to Ballarat.
12 Month - "Severe deficiencies" exist around Melbourne, Geelong and Ballarat including an area of "Lowest on record" for east and west of Melbourne. "Serious deficiencies" also exist in southern New South Wales and areas of western Victoria and parts of East Gippsland.
The details in this post are prepared using data from:-
- Bureau of Meteorology.
- Weatherzone.
- Goulburn Murray Water.
- Melbourne Water
In particular, Melbourne's water reservoirs saw their first increase in water supply since December 2008 in which total capacity has risen by 1% from 26.1% to 27% indicating that rainfall has fallen in the upper catchments. Average rainfalls of 130 mm occurred in Melbourne's water catchment during July which is above the long term average of 107.4 mm.
While rainfall improved during July some areas still show rainfall deficits as shown in the regional centres as part of this case study.
Town / City Rainfall at end of July Normal average rainfall
Albury / Wodonga 252.8 mm on 58 days 314 mm on 57 days
Ararat 241.4 mm on 75 days 318 mm on 80 days
Bairnsdale 151 mm on 68 days 360.5 mm on 77.2 days
Ballarat 221.2 mm on 88 days 373.3 mm on 90.4 days
Bendigo 191 mm on 63 days 254.9 mm on 57.5 days
Casterton 350.6 mm on 122 days 347.9 mm on 91.2 days
Echuca 130.4 mm on 56 days 241 mm on 48 days
Geelong 154.6 mm on 83 days 287.3 mm on 77.8 days
Hamilton 271.8 mm on 108 days 309.9 mm on 95.3 days
Horsham 213.2 mm on 63 days 190.9 mm on 63.4 days
Kerang 119.5 mm on 44 days 205.7 mm on 40.8 days
Melbourne 165.6 mm on 62 days 355.9 mm on 79.5 days
Mt Hotham 662.2 mm on 80 days 738.5 mm on 89 days
Mildura 105.2 mm on 42 days 151.4 mm on 38 days
Portland 392.2 mm on 97 days 377 mm on 97.5 days
Shepparton 157 mm on 62 days 215.9 mm on 52.5 days
Wangaratta 226.8 mm on 61 days 356.4 mm on 61.5 days
Warrnambool 372.4 mm on 105 days 379 mm on 108 days
New South Wales
Griffith 152.4 mm on 39 days 223.5 mm on 39.7 days
Hay 173.6 mm on 39 days 213.1 mm on 56.8 days
Wagga Wagga 176.4 mm on 49 days 318.4 mm on 56.8 days
One positive for the month of July is that enough rain has fallen in some areas to reduce the size of the rainfall deficits especially in areas around Horsham, Portland and Casterton. However deficits still remain over many areas of the state.
Reservoirs:
The water levels in the reservoirs are still low indicating that more rainfall is needed to replenish the dams.
Dam name Capacity as at 5 August 2009 Capacity as at 5 August 2008
Cairn Curran 1.86% 4.90%
Dartmouth Reservoir 22.69% 18.88%
Eildon Reservoir 17.2% 18.46%
Hume 17.34% 22.16%
Lake Eppalock 5.73% 6.53%
Tullaroop 4.32% 5.23%
The reservoirs in the case study except for that at Dartmouth Reservoir are showing lower water levels for early August 2009 than at the same time for 2008. While runoff is occurring in the upper catchments and into the dams, much more rainfall and snowmelt is required before the water situation improves.
It is concluded that there has been some short term improvement but more rainfall is required before the water situation improves for the state and for southern New South Wales.
The plots will be loaded on under a separate heading.
Harley Pearman
-
Rainfall plot and 12 month drought map for Victoria to end of July 2009
The July rainfall plot generated from the Bureau of Meteorology "Water and the Land" is provided below and shows that south west Victoria and North East Victoria has received better rainfalls. Only East Gippsland and far NW Victoria has missed out on something during the month.
Additionally, the 12 month drought plot from 1 August 2008 to 31 July 2009 also generated from the same site shows the updated drought situation with the worst affected area concentrated around and close to Melbourne.
Harley Pearman
-
Possible rainfall for Victoria - August to October 2009
While the latest POAMA (Predictive Ocean Atmosphere Model for Australia) models and ensembles continue to show drier than normal conditions expected across Eastern Australia for the remainder of 2009 and into 2010 with a possible peak El Nino in January and February 2010, it is noted that some useful rainfall should still be occurring across some areas of Victoria during the August to October period. In particular:-
a) The 100 mm rainfall plot generated from the "Water and the Land site - Bureau of Meteorology" shows most of Victoria having an 85% chance of receiving at least this amount of rain during the period. The North West region is expected to remain reasonably dry.
b) The 150 mm rainfall plot generated from the "Water and The Land site - Bureau of Meteorology" shows the North East ranges and parts of Gippsland and the South West coast having an 85% chance of receiving at least this amount of rain. The remainder of the state has a lower chance of receiving significant rainfalls with the North West and Northern regions expected to remain reasonably dry.
The 200 mm rainfall plot show much smaller areas that may receive this amount which is largely limited to portions of the North East Highlands.
The latest Bureau of Meteorology rainfall updates show that Southern New South Wales and approximately 70% of the state of Victoria having only a 40% chance of reaching average rainfall during the next three months. However the area around Gippsland has a 50% chance of receiving average rainfall for the next three months.
In addition, the latest POAMA plots continue to show an El Nino development for 2009 and into 2010 with sea surface temperatures expected to be above average for the December to February period. Additionally the NINO 34 Plumes continue to show a peak during the January to February period.
The possible rainfall plots for Victoria and Southern New South Wales for the period August to October 2009 for 100 mm and 150 mm are provided below.
Harley Pearman
-
So, Harley, based on your statements re: the drought in VIC, do you think we might be pulling out of this severe drought soon? or are we still going to be covered in dust?
Big Pete
-
Likely POAMA Daily rainfall plots September to November 2009
I have been playing around with the likely POAMA daily rainfall ensembles for September to November 2009. The best way to answer Big Pete's question is to upload the ensembles produced. It is advised that POAMA (Prepared by the CSIRO) is only experimental at this stage but should give some indication how conditions are likely to prevail. Unfortunately it does not appear that major rainfall events are on the horizon for much of Victoria. While some rain is envisaged it is unlikely to be enough to overcome current conditions.
September - The ensemble suggest average daily rainfalls of minus 0.2 to minus 0.5 mm per day range for most of Victoria and much of Eastern New South Wales.
October - The ensemble suggest average or near average daily rainfalls for Melbourne within the range of 0.2 to negative 0.2 mm range. North East Victoria and Northern Victoria is in the minus 0.2 to minus 0.5 mm range per day which suggests below average falls. The ensemble suggest that eastern New South Wales will experience below average falls as well.
November - The ensemble suggests average or near average daily rainfalls for much of Victoria within the range of 0.2 to Negative 0.2 mm per day. It appears that no big events are suggested but enough rainfall to approach at least "average". Eastern Victoria is shown as being in the minus 0.2 to minus 0.5 mm range for daily rainfalls.
The Ensembles are provided below for the three months.
Harley Pearman
-
August rainfall Deficits continue but conditions ease in some South West regions
Rainfall deficits across much of Victoria continue however the dry conditions have eased across some parts of the state notably the South West.
Specifically the rainfall for the towns and cities in the case study to the end of August 2009 are outlined below:-
Location Rainfall to end of August Normal rainfall Deficits
Albury Wodonga 314.8 mm on 83 days 381.7 mm on 70 days -66.9 mm
Ararat 310.2 mm on 98 days 385.9 mm on 97.9 days -75.7 mm
Bairnsdale 189 mm on 82 days 396.5 mm on 90.7 days -207.5 mm
Ballarat 286.8 mm on 110 days 445.9 mm on 109.8 days -159.1 mm
Bendigo 251.6 mm on 85 days 300.7 mm -49.1 mm
Casterton 450.9 mm on 146 days 432.6 mm on 112 days Plus 18.3 mm
Echuca 149.4 mm on 72 days 283 mm on 59.3 days -133.6 mm
Geelong 203.2 mm on 106 days 335.4 mm on 94 days -132.2 mm
Hamilton 366.4 mm on 131 days 386.9 mm on 116 days -20.5 mm
Horsham 262.4 mm on 83 days 227.5 mm on 79.2 days Plus 34.9 mm
Kerang 137.7 mm on 56 days 242.7 mm on 50.1 days -105 mm
Melbourne 208 mm on 79 days 406.1 mm on 95 days -198 mm
Mt Hotham 835 mm on 107 days 882.2 mm on 105.9 days - 47.2 mm
Mildura 112.6 mm on 45 days 178.2 mm on 47.1 days -65.6 mm
Portland 528.2 mm on 124 days 474.4 mm on 119.3 days Plus 53.8 mm
Shepparton 183.2 mm on 81 days 262.2 mm on 64.1 days -79 mm
Wangaratta 265.6 mm on 84 days 414 mm on 75.5 days -148.4 mm
Warrnambool 499.6 mm on 131 days 470.4 mm on 129.9 days Plus 29.2 mm
New South Wales
Griffith 165.6 mm on 47 days 259.8 mm on 48.7 days -94.2 mm
Hay 184.2 mm on 50 days 245.3 mm on 46.5 days -61.1 mm
Wagga Wagga 208.2 mm on 66 days 369.8 mm on 69.9 days -161.6 mm
A trend is emerging in which South West Victoria is now receiving rainfalls which are close to or slightly above the average and some centres in that region appear to be satisfactory. However Melbourne and Gippsland plus the Northern agriculture country as well as Southern New South Wales continue to show deficits. In particular:-
- Bairnsdale is showing a rainfall deficit that exceeds the amount of rain that has fallen so far.
- The rainfall deficit for Melbourne is still significant.
- The number of rainy days is satisfactory but the amounts that are falling are below average in most centres.
Some places received a wet August which has helped such as 106.2 mm at Casterton, 136 mm at Portland and 138 mm at Warrnambool. This has helped to reduce the deficits in the centres stated. Additionally, near average rainfalls occurred at Albury Wodonga.
When comparing the dams in the case study, it is becoming evident that the dams are unlikely to fill before summer.
Dam levels at 3 September 2009.
Dam name Storage levels Same time as 2008 Rainfall for 2009 Rainfall for same period 2008
Cairn Curren 2.63% 5.80% 213 mm 219 mm
Dartmouth 24.6% 19.71% 481.2 mm 493.4 mm
Eildon 21.78% 21.84% 378.6 mm 411.9 mm
Eppalock 5.80% 6.95% 228.6 mm 228.1 mm
Hume 24.05% 28.12% 320.6 mm 343.4 mm
Tullaroop 4.54% 6.38% 225.1 mm 179.8 mm
Dam levels are still low for September and some storages are worse off although Dartmouth is better off when compared to the same time last year (As at 3 September 2009). There has been inflows into Dartmouth and Hume from rainfall and melting snow since the beginning of August 2009.
According to Goulburn Murray Water, enough water has been stored in the upper catchment reservoirs to ensure essential services are maintained throughout summer but the system is heavily stressed.
The Melbourne system is still stressed in which storage capacity is at 28.8% as at 4 September 2009 with Melbourne's largest Reservoir only at 17.3% or holding 184,873 megalitres.
Overall parts of Victoria has seen some improvement during August but Gippsland and much of the Northern Country are still heavily stressed.
Information on this post is derived from:-
1 - Weatherzone (Rainfall data and rainfall averages).
2 - Bureau of Meteorology (Rainfall data and averages).
2 - Goulburn Murray Water (Rainfall and dam levels as 3/9/2009).
3 - Melbourne Water (Storage levels).
The plots describing the drought and drought statement, actual rainfall and rainfall anomalies are to be provided as a separate post.
Harley Pearman
-
Rainfall anomalies Victoria and Southern NSW August 2009
As per the previous post the actual rainfall and anomalies and drought statement for August 2009 is provided below.
Rainfall for August 2009
The rainfall for August is as follows:-
North West Victoria 10-25 mm.
Northern Country 25-50 mm.
Central and North East Hills 50-100 mm.
South West and North East Highlands 100-200 mm.
Gippsland 25-50 mm.
Southern New South Wales close to the Murray River received between 10-25 mm but it was drier further north.
The South West portion of Victoria received some good falls. The plot showing this is provided below which is generated from the Bureau of Meteorology "Land and Water" site.
Rainfall anomalies for August
The rainfall anomalies for August are as follows:-
South West Victoria has received above average rainfall in the order of 10 to 50 mm above average.
North West Victoria has received 10 to 25 mm below average rainfalls.
North East Victoria has received 10 to 50 mm below average rainfall however a small portion close to the New South Wales border received from average to 50 mm above average rainfall for the month.
Gippsland received 25 to 50 mm below average rainfall but it was drier at the far eastern portion of the state.
Southern New South Wales received from 10 mm to 50 mm below average rainfall but it was drier further north from the Murray River.
South West Victoria has seen some recovery. The plot showing this generated from the Bureau of Meteorology "Land and Water" site is provided below.
Drought Statement
The drought statement for August is as follows:-
3 Monthly anomalies - The worst of the short term deficits have been removed.
6 Monthly anomalies - Serious rainfall deficiencies exist around Melbourne and severe rainfall deficiencies exist for Eastern Victoria.
9 Monthly anomalies - Serious to severe rainfall deficiencies exist across southern and Eastern Victoria.
12 Monthly statement - Southern Victoria around Melbourne is hit hard including severe rainfall deficiencies and the Dandenongs experiencing "Lowest rainfall on record" from 1 September 2008 to 31 August 2009. The plot showing this generated from the Bureau of Meteorology "Land and Water" site is provided below.
Harley Pearman
-
Latest Seasonal rainfalls - Southern New South Wales and Victoria - Spring 2009
Latest El Nino Phase
The latest graphs and plots show the ENSO at Negative 5 as at 9/9/2009 but has not yet reached El Nino thresholds of Negative 7 (BOM 9/9/2009). Looking at the POAMA plots and Ensembles, it is noted that a large volume of warmer than normal surface water still lies across the Equatorial Pacific Ocean which is 1C above the normal but it appears that it will not reach Australian waters. Instead the POAMA is showing some warming of waters around Northern Australia during the summer months especially in February of 0.5C to 1.5C. The POAMA still suggest a peak in January however it seems that a weak El Nino phase is likely to eventuate but still enough to impact on rainfall.
Rainfall
I have been looking at the latest POAMA (Experimental Program produced by the CSIRO for research purposes) for rainfall predictions for spring and have noted a change particularly for South West Victoria. In particular I have noticed some recent recovery occurring in South West Victoria in which rainfalls seem to be returning to normal or approaching slightly above average. The latest POAMA plot / Ensemble seem to suggest that it may continue at least in this portion of the state. However this is limited in extent and the latest Seasonal POAMA Plot / Ensemble does not suggest good news elsewhere. The monthly Ensembles remain largely the same for the rest of the state. In particular:-
- South West Victoria "Showing Average" - Minus 0.2 to Plus 0.2 Range. It may suggest that conditions will not be as dry as first suggested in that region.
- Most of Victoria - Minus 0.2 to Minus 0.5 range.
- Far Eastern Victoria and far North East Victoria - Minus 0.5 to Minus 1 Range.
The Seasonal Rainfall Ensemble also show that much of inland New South Wales lies within the Minus 0.2 to Minus 0.5 banding while Eastern New South Wales lies within the Minus 0.5 to Minus 1 banding.
The Seasonal Plot for 3 months - Mean 24 Hour Rainfall Anomaly - September to November in which the variables were set to "Day 1" - Lead Time "Set to 3 Months" is provided below.
Harley Pearman
-
September rainfall eases short term dry conditions
Useful September rainfall across large areas of Victoria has helped to ease the rainfall deficits although deficits still remain. In particular, most regions, towns and cities received average to above average rainfall for the month with a few exceptions. The rainfall for the selected regional centres is provided below.
Town / City Rainfall to end of September 09 Average rainfall to end of month Deficit
Albury/Wodonga 376.2 mm on 93 days 440 mm on 81 days Minus 63.8 mm
Ararat 395 mm on 118 days 447 mm on 113.4 days Minus 52 mm
Bairnsdale 240.2 mm on 98 days 451.3 mm on 104.6 days Minus 211.1 mm
Ballarat 375.8 mm on 128 days 517.4 mm on 125.5 days Minus 141.6 mm
Bendigo 304.6 mm on 100 days 348.9 mm on 80.7 days Minus 44.3 mm
Casterton 539.1 mm on 174 days 506.2 mm on 130.2 days Plus 32.9 mm
Echuca 179.4 mm on 80 days 322.2 mm on 68.8 days Minus143.2 mm
Geelong 257.2 mm on 122 days 384.1 mm on 109.8 days Minus 126.9 mm
Hamilton 440.2 mm on 151 days 457.5 mm on 134 days Minus 17.3 mm
Horsham 345.4 mm on 98 days 262.4 mm on 92.5 days Plus 83 mm
Kerang 185.3 mm on 65 days 278.2 mm on 58.1 days Minus 86.9 mm
Melbourne 275.2 mm on 94 days 464 mm on 109.8 days Minus 188.8 mm
Mt Hotham 1012.6 mm on 126 days 1,015.3 mm on 119.3 days Minus 2.7 mm
Mildura 141.6 mm on 55 days 205.2 mm on 54.5 days Minus 63.6 mm
Portland 625.2 mm on 140 days 551.1 mm on 137.8 days Plus 74 mm
Shepparton 227.6 mm on 92 days 300 mm on 74 days Minus 72.4 mm
Wangaratta 319.2 mm on 96 days 470.7 mm on 87.7 days Minus 151.5 mm
Warrnambool 583.2 mm on 152 days 538.8 mm on 149.8 days Plus 44.4 mm
New South Wales
Griffith 185 mm on 55 days 293.4 mm on 56.3 days Minus 108.4 mm
Hay 202.6 mm on 57 days 276.8 mm on 53.2 days Minus 74.2 mm
Wagga Wagga 241 mm on 75 days 419.6 mm on 80.7 days Minus 178.6 mm
Comments:
The above shows that some places are relatively satisfactory. In particular, South West Victoria is also in a satisfactory position with respect to rainfall. Further, rainfall deficits across the North East highlands of Victoria have closed and rainfalls are near average. However, places like Bairnsdale, Echuca, Melbourne, Wagga Wagga and Wangaratta still continue to experience significant rainfall deficits.
Rainfall in September has helped to ease some of the short term deficits and places like Casterton, Horsham, Portland and Warrnambool experienced average to above average rainfall for the month.
However many areas are still stressed.
Storage levels:
September was a good month and some good inflows were recorded into upper catchment storages. The storages in the case study are shown below:-
Dam Storage level at 7 October 09 Storage level at same time 2008
Cairn Curren 5.61% 6.17%
Dartmouth 27.68% 21.7%
Eildon 29.14% 23.55%
Eppalock 7.87% 6.9%
Hume 34.45% 35%
Tullaroop 5.75% 6.85%
There has been an improvement at Hume, Dartmouth and Eildon Reservoirs mainly from better inflows from rainfall and snow melt and generally the big dams are in a better condition than at the same time for 2008.
However smaller dams away from the highlands do not fare as well.
There is enough water to meet some allocations now but the system is still stressed and it is doubtful that the dams will fill before the onset of summer.
Melbourne Water storages also show an improvement with its water capacity now at 32% which is an improvement on the 28.8% at 4 September 2009. Melbourne's largest Reservoir being Thompson Reservoir which can hold 1,068,000 megalitres is only holding 204,982 megalitres or 19.2% (7/10/2009).
However while improvements have occurred, the system is still stressed reflecting the rainfall deficits that have occurred.
The plots showing the September rainfall, rainfall anomalies and the drought statement is provided as a separate post.
So overall, an improvement has occurred in many areas and South West Victoria is satisfactory. However much of the state as well as South West New South Wales still show rainfall deficits.
The data from this post is derived from
Bureau of Meteorology (Rainfall for the various weather stations).
Weatherzone (Monthly climatic data for the locations).
Goulburn Murray Water (Dam levels).
Melbourne Water.
Harley Pearman
-
Drought statement for September 2009
Rainfall amounts:
The plot generated from the Bureau of Meteorology - Land and Water site shows that good rains fell across much of Victoria during the month of September. The plot is provided below. In particular:-
- The majority of the east and south received more than 50 mm of rain during the month.
- Large areas received between 50 mm and 100 mm of rain for the month.
- Melbourne Water catchments and the North East received between 100 mm and 200 mm of rain.
- At least 50 mm of rain fell across large areas of North West Victoria.
- Isolated totals of up to 200 mm fell.
Lighter falls fell along the Murray River region but further north into New South Wales, rainfall tapered away and only light falls occurred for the month.
Rainfall anomalies:
During September, large areas of Victoria received at least average to above average rainfall for the month including Melbourne. In particular, Melbourne's water catchment, North East Victoria highlands and even North West Victoria (But mainly south of the Murray River) benefitted from September rainfalls. Hence the rainfall Anomaly plot provided below generated from the Bureau of Meteorology - Land and Water site shows that beneficial rains occurred across most areas of the state. There were a few pockets that received less than normal rainfall but generally September was a good month for rainfall across the state.
However, further north into New South Wales, September rainfalls tapered away increasing towards a deficit for the month.
Drought statement:
The 3 month plot shows no rainfall deficiencies across Victoria or Southern New South Wales. Rainfall in September has eliminated all the short term rainfall deficiencies that were previously occurring.
The 6 month plot shows only a small area in Eastern Victoria suffering from "Serious Rainfall deficiency". Following good September rainfall, much of the short term deficiencies have been removed.
The 9 monthly plot shows Melbourne and Southern Victoria suffering long term rainfall deficiencies including "Severe deficiencies". In Eastern Victoria, Gippsland continues to show "Severe deficiencies" to "Lowest on record". The area indicated as "Lowest on record" is inland from the coast but it crosses into South East New South Wales.
The 12 monthly drought statement still shows Melbourne suffering "Serious rainfall deficiency" which increases to "Severe Rainfall deficiency" for the Dandenongs east of Melbourne. There is also an area of "Serious rainfall deficiency" in far Eastern Victoria mainly along the state border of New South Wales. The rest of Victoria is generally satisfactory.
The 12 monthly drought statement plot generated from the Bureau of Meteorology - Land and Water site is provided below.
Harley Pearman
-
Likely October to December Rainfall 2009
I have been looking at some of the latest El Nino plots from POAMA (CSIRO) and sea surface temperature plots. The sea surface temperatures do in fact show "El Nino" Conditions and the oceans have warmed but the atmosphere conditions do not show it. The Southern Oscillation Index is currently Plus 3 or Neutral and the SOI now does not show an "El Nino" trend. Signals appear to be mixed. It is also noted that waters in the Eastern Indian Ocean are warmer than waters in the Western Indian Ocean which has helped over recent weeks in a positive way for Victoria.
The POAMA models continue to show El Nino conditions for sea surface temperatures with a peak during January and February of 1.64C and 1.63C above average but waning thereafter. The level of warming is not as strong as shown in previous months. It still appears to be a weak El Nino but signals seem to be mixed. It still appears that rainfall will be affected for Southern Australia.
Chance of exceeding median rainfall:
The Bureau of Meteorology rainfall prognoses for Victoria looks poor for the state. The plot shows that Northern Victoria has a 40% chance of exceeding median rainfall, dropping to 35% to 40% for Central areas, 30% to 35% for the South West and as low as 20% to 25% for some South West areas.
This is in contrast to the current rainfall regime which has been average to above average in this region. It may be a case that enough has fallen in this region to offset the likely dry for a period without significant stress assuming the model is accurate. Indications are, the good falls that have been occurring of recent weeks to close or reduce some of the deficits will not continue.
Chance of 100 mm Rainfall:
For the state of Victoria, the North West has a low chance of receiving 100 mm of rain being as low as 15% and as high as 35%. Generally large areas of the state should see at least 100 mm of rain varying between 25% and 85%. The regions with the greatest chance include the South West, Melbourne, North East and the East. However there is evidence of a drying trend taking hold at least across the West, North West and Northern Country and crossing into New South Wales.
While September saw some good rainfalls as per the models there is evidence to suggest that this will not continue and rainfalls will drop as summer approaches.
Chance of 200 mm Rainfall
Very few areas have much chance of receiving up to 200 mm of rainfall. The North West of the state, South West and Northern regions are considered to have a low chance of between 15% and 35% of receiving this amount of rain. Only Eastern Victoria has any meaningful chance of receiving this amount of rain ranging from a low 15% to a high of 75%. The highest chances lie within the ranges east of Melbourne and the North East ranges.
Western Victoria and Northern Victoria appear to show a drying trend for the October to December period.
The model plots referred to above have been generated from the Bureau of Meteorology "Water and the Land" for the "Chance of 100 mm Rainfall" and "Chance of 200 mm Rainfall.
Harley Pearman
-
October a dry month across much of Victoria - Some rainfall deficits worsen
The month of October saw good rainfall in East Gippsland and the North East Highlands but most other areas started to dry out as suggested by the long term weather models. In particular, October was a dry month across large areas of the state as well as inland South West New South Wales.
The table below shows the latest rainfall situation across the regional towns and cities and it shows that some centres are experiencing significant rainfall deficits. The South West portion of Victoria remains satisfactory. The details are obtained via:-
- Weatherzone (Specific to climatology data).
- Bureau of Meteorology (Specific to rainfall data for the month of October).
- Goulburn Murray Water (Dam levels as at 1 November 2009).
- Melbourne Water.
Place name Rainfall to 31 Oct Normal Rainfall Oct Rainfall Deficit
Albury Wodonga 402.2 mm on 101 days 489.5 mm on 88.8 days 26 mm Minus 87.5 mm
Ararat 421.8 mm on 129 days 506 mm on 126.3 days 26.8 mm Minus 84.2 mm
Bairnsdale 325 mm on 111 days 509.6 mm on 118.3 days 84.8 mm Minus 184.6 mm
Ballarat 408 mm on 140 days 584.9 mm on 142 days 31.6 mm Minus 176.9 mm
Bendigo 338.2 mm on 109 days 390.5 mm on 90.1 days 33.6 mm Minus 52.3 mm
Casterton 585.7 mm on 188 days 564.3 mm on 145.8 days 46 mm Plus 21 mm
Echuca 200 mm on 88 days 364.7 mm on 77.2 days 20.6 mm Minus 164.7 mm
Geelong 283.4 mm on 134 days 437 mm on 123.4 days 26.2 mm Minus 153.6 mm
Hamilton 474.6 mm on 167 days 514.6 mm on 150.8 days 36.2 mm Minus 38.2 mm
Horsham 366.6 mm on 104 days 296 mm on 101.5 days 21 mm Plus 70.6 mm
Kerang 202.7 mm on 73 days 315.8 mm on 65 days 17.4 mm Minus 113.1 mm
Mt Hotham 1,135 mm on 144 days 1,117.5 mm on 130.3 days 122.4 mm Plus 17.5 mm
Melbourne 300.8 mm on 105 days 530.2 mm on 123.9 days 21.8 mm Minus 229.4 mm
Mildura 153.8 mm on 61 days 235 mm on 61.5 days 10.4 mm Minus 81.2 mm
Portland 666.2 mm on 155 days 598.9 mm on 154.1 days 41 mm Plus 67.3 mm
Shepparton 248.2 mm on 101 days 332.9 mm on 82.8 days 20.6 mm Minus 84.7 mm
Swan Hill 205.8 mm on 79 days 219.7 mm on 64.6 days 13.6 mm Minus 13.9 mm
Wangaratta 351.2 mm on 106 days 522.7 mm on 96.9 days 32 mm Minus 171.5 mm
Warrnambool 634.8 mm on 169 days 601.8 mm on 168.2 days 51.6 mm Plus 33 mm
South West New South Wales
Place Name Rainfall to 31 Oct Normal Rainfall Oct Rainfall Deficit
Griffith 204 mm on 65 days 333.1 mm on 62.6 days 19 mm Minus 129.1 mm
Hay 207.8 mm on 62 days 311.9 mm on 59.4 days 5.8 mm Minus 104 mm
Wagga Wagga 269 mm on 83 days 477.8 mm on 90.4 days 27 mm Minus 208.8 mm
In reference to the table above:-
- Bairnsdale received short term relief in which almost 85 mm of rain fell for the month being well above the average. However the rainfall deficit here is still 184.6 mm.
- The rainfall deficit for Melbourne worsened and now stands at 229.4 mm.
- The rainfall deficit within areas of the North East Highlands finally closed.
- At Wagga Wagga, the rainfall deficit reached 200 mm. It has been a very dry year in this region.
- Much of Northern and North Western Victoria started to dry out following a dry month.
Dam Name Capacity as at 1/11/2009 Capacity as at 1/11/2008
Cairn Curren 6.55% 5.8%
Dartmouth 30.27% 22.24%
Eildon 33.25% 22.78%
Eppalock 8.21% 6.67%
Hume 40.28% 33.11%
Tullaroop 6.06% 6.51%
(Source - Goulburn Murray Water 1/11/2009)
Lake Mokoan now holds 3.57% capacity which is a slight improvement. Generally the reservoirs hold more water than at the same time last year but it is clear that the reservoirs will not fill before the onset of summer.
As per the models, October saw a drier month across much of Victoria except for the Eastern areas being Gippsland and the North East Highlands. Away from the ranges, rainfall was mostly below average tending to well below average. Rainfall deficits are now very significant for places like Melbourne, Wagga Wagga and Wangaratta in the case study and rainfall deficits have started to widen elsewhere. This was caused by below average rainfall across large areas of the state.
Melbourne's water supply currently stand at 37.9% and there has been some good recent inflows mainly due to good runoff and rainfall in the upper catchments. This is an improvement on the same time last year where storage levels were at 33.9% capacity. Additionally, Melbourne's small dams look quite healthy in terms of storage capacity but the main water supply being Thompson Reservoir is only at 20.7% capacity (Melbourne Water 1/11/2009).
The dams are generally holding more water supply than at the same time last year mainly due to higher rainfall in the upper catchments however this rainfall did not penetrate into the Northern Plains for the month. Many areas are experiencing wide rainfall deficits which is not good approaching summer. Rainfall stress is evident in Northern areas and North Western areas of the state and well into New South Wales, especially across the inland regions. The plots showing these and the drought statement for the month of October will be completed as a separate statement.
Harley Pearman
-
Drought statement for October - Victoria and South West New South Wales
The drought statement is provided below.
3 month drought plot
A new region but within Western / Central Inland / South Western New South Wales is suffering serious to severe water stress. This appears to be a new region to watch due to low rainfall occurring. This region lies well within the Murray Darling Basin. The state of Victoria is effectively satisfactory due to good September rainfall having an impact.
6 month drought plot
The state of Victoria is mostly satisfactory except for small areas North East and South East of Melbourne.
9 month drought plot
Serious rainfall deficiencies exist around Melbourne and South East of Melbourne as well as parts of Gippsland. The rest of Victoria despite the rainfall deficiencies is satisfactory.
12 monthly drought plot:
The 12 month drought plot shows Melbourne continuing to suffer serious rainfall rainfall deficiency. The rest of Victoria despite some large rainfall deficits is satisfactory.
3 Month drought plot for the Murray Darling Basin
A different plot is used for October which is specific to the Murray Darling Basin. This is used because a new region suffering serious water deficiency and concern is becoming evident in South West and Western New South Wales specifically within the basin itself. The three month plot has been generated from the Bureau of Meteorology "Water and the Land" site.
Harley Pearman
-
November 2009 Rainfall - Rainfall deficits close
A comprehensive analysis of November rainfall is provided in the table below as an attachment. The rainfall data as well as the averages is sourced from Weatherzone and the Bureau of Meteorology however I have calculated the deficit or surplus using the data provided. This has been completed in this manner to show in greater detail the current situation regarding rainfall for the selected centres. In particular the table shows the following:-
- Ballarat and Geelong received well above average falls for the month and rainfall deficits declined.
- Melbourne received falls of up to 100 mm, well above the average of 59 mm. This reduced the outstanding deficit to 188.7 mm.
- Kerang received 98.4 mm of rain which is 3 times the average for the month. This fall significantly reduced the rainfall deficit for the year.
- Mildura received 63 mm of rain being well above the average of 24.4 mm. The rainfall deficit here was reduced. There were generally good rains across the Mallee which were not expected.
- Swan Hill received almost 80 mm of rain for the month which is well above the average of 45.6 mm. November was such a good month that the rainfall deficit for Swan Hill was closed.
- Wagga Wagga has and continues to suffer from a very dry year and the rainfall deficit here has now topped 225.6 mm.
- The region around Bairnsdale remains dry with the rainfall deficit still significant being almost 224 mm. Bairnsdale has had a dry year recording 369 mm to the end of November 2009.
- The South West part of Victoria is still satisfactory and so is the North East Highlands following good rainfalls.
It appears that rainfall patterns has gone against the expected dire predictions for the October to December period in which while November was a warm / hot month, it was also a wet month in large areas that helped to close some more of the rainfall deficits that existed across the state. There is still a long way to go however the situation across Victoria did improve.
Dam levels
As with many other dams and water supplies across the state, the dams in the case study did not fill. The major dams are now beginning to register declining water levels at the beginning of the summer season. While dams are low, it is acknowledged that they are holding more water than at the same time for 2008. Similar to water supplies managed by the Goulburn Murray Water Authority, supplies managed by Melbourne Water register 38% at the start of December 2009. Melbourne's main water supply Thompson Reservoir is only holding 21.1% capacity (Melbourne Water). Additionally Melbourne is going into the summer months with the second lowest storage of available water supply recorded (Melbourne Water 3/12/09).
Dam name Level as at 3/12/09 Level at same time last year
Cairn Curren 6.69% 5.26% (Rising)
Dartmouth 30.94% 22.53% (Falling)
Eildon 32.71% 22.72% (Falling)
Eppalock 7.67% 6.63% (Falling)
Hume 36.13% 28.96% (Falling
Tullaroop 6.03% 6.12% (Rising)
As described above the comprehensive table describing rainfall for the selected towns and cities for November 2009 is provided as an attachment below.
Harley Pearman
-
Drought statement for November 2009
Following on from the previous post, it is clear that good November rainfall has helped to eliminate much of the short term rainfall deficiencies however long term deficits and water shortages still remain. It is also noted that yearly deficits still exists in many areas and some are significant but overall there have been short term improvements. In particular:-
3 Monthy plot - All short term deficits have been removed. Excellent November rains especially across North West Victoria and around Melbourne have removed the worst of the short term deficits. Victoria and South West New South Wales appear to be satisfactory.
6 Monthly plot - November and spring rains have eliminated the short term deficits. In the short term, Victoria and South West New South Wales appear to be satisfactory.
9 Monthly plot - East Gippsland is suffering serious to severe rainfall deficiencies. For Melbourne, springs rains and excellent November rains have helped to reduce the rainfall deficits. The short term deficits for Melbourne have been removed but long term deficits remain.
12 Monthly plot - There are some serious rainfall deficiencies east and south east of Melbourne. Serious to severe rainfall deficiencies exists across Gippsland and East Gippsland being eastern Victoria.
The 12 monthly plot for South Eastern Australia produced at the Bureau of Meteorology "Water and the Land" site is provided below and generally there are some improvements across the state of Victoria and inland South West New South Wales.
Harley Pearman
-
December rainfall for Victoria and inland South West New South Wales 2009
While much of New South Wales enjoyed above average rainfall for December, much of Victoria experienced rainfalls were either below average or average at best. The attached table provides a comprehensive review of rainfall for the month as well as for the year ending 31 December 2009 for the towns and cities in the case study.
While the final 2009 drought statement is separate from this thread it is concluded that:-
- During the 12 month period, South West Victoria pulled out of drought as rainfall returned to average or slightly above average. Dry conditions still prevailed across the north and east away from the North East Highlands.
- The Griffith and Wagga Wagga region experienced a wetter than normal December but the amount could not erase the yearly deficit.
- The Albury / Wodonga region experienced a dry December resulting in an increase in the rainfall deficit for the year.
- Regions around Bairnsdale, Echuca, Melbourne, Wagga Wagga and Wangaratta experienced a dry year and a few areas had rainfall deficits exceeding 200 mm.
The table referred to is attached below. The data in the 2009 case study has been compiled from weather stations via Weatherzone (Climatic averages) and Bureau of Meteorology for monthly rainfall although the final deficits have been calculated out 5/1/2010 to complete the table.
Harley Pearman
-
Final drought statement for 2009
The final drought statement for 2009 is covered below.
Rainfall deciles:
The first plot covering the whole of 2009 shows the Rainfall Deciles for the Murray Darling Basin and shows that rainfall was below average for much of eastern and northern Victoria. It also shows that rainfall was well below average across much of southern Victoria east from Melbourne to the New South Wales state border as well as very dry conditions prevailing around Wagga Wagga and west of Canberra. Generally western Victoria fared better and appears to be satisfactory.
Rainfall anomalies:
In western Victoria, rainfall returned to normal or near normal with the yearly anomalies within 0 to 100 mm of average or slightly below average. It is noted that a few areas received slightly above average rainfall over the course of 2009. Generally Western Victoria pulled out of drought and saw improvements.
However across much of the north and east of the state as well as southern New South Wales, rainfall deficits were much higher being 100 to 200 mm below average and even up to 200 mm below average (Although some affected regions are placed within the 200 to 400 mm banding - Below Average shown as yellow on the plot).
12 month drought statement:
Following good spring rains and some helpful rains in some localities throughout December such as around Melbourne and Bairnsdale, the 3 month, 6 month and 9 month rainfall deficiencies have almost been removed. It is only the long term deficiencies that remain.
The 12 month rainfall deficiency plot highlights ongoing rainfall deficits and drought across southern and eastern Victoria including small areas west of Canberra mainly around and near Wagga Wagga.
It appears that this topic can be concluded at this point following good rains at the commencement of January 2010 across many regions. Such good rains have been reasonably widespread across the state although while more is needed, it is a more positive start to the year when compared to the start of 2009 which precipitated this topic. Lets hope the improvements continue throughout 2010.
The plots referred to above are attached below. The plots have been generated using the Bureau of Meteorology "Water and the Land" 5/1/2010.
Harley Pearman