Topic: Lets Look at the other side: VIC, SA, TAS day to day weather

[Jimmy Deguara]

Hi Harley,

Just curious

It is good to see this rain but it indicates that this La Nina has taken longer to penetrate inland than previous La Nina's. This could suggest that La Nina's in future could lose their impact in inland SW NSW and northern Victoria.

Why would you suggest that because of this La Nina, that future La Ninas may take longer to penetrate inland? Would you not have thought this a coincidence? If it takes longer to penetrate inland does this mean that the La Nina will last longer?

Interesting for a discussion here - I am curious of your reasoning that's all. I have no answer otherwise except part logic and atypical climatic patterns.

Regards,

Jimmy Deguara

[Peter J]

Hi all,

Monday Feb 4, 2008.

So far the "promised" rain for this part (the outer-east of Melbourne) has yet to arrive. We did undergo a severe thunderstorm warning for a short time last nite. The clouds were there, and some of them had the darker grey look about them, but no thunder or lightning was to be seen. Let alone, still 0mm in the gauge for yesterday and to 12:30pm today (monday) - and just 5.4mm for the first 4 days. There is a forecast in place for showers and local thunder for this afternoon - and some chance of these storms becoming severe in the NE and E of Vic. Worth keeping an eye on.

It has been good to hear NSW and QLD are getting good falls in their catchment areas, as we know down here too, good rains help us all to survive with drinking water a bit longer. But we are missing out in Melbourne. We had just under average rainfall in January - and most of that rain came in 2 days! And this month is expected to be above average, just that at the moment I can't see that being possible without a few drenchings.

Big Pete

[Peter J]

Just in relation to my previous post below - there has been one severe storm go through Melbourne's outer west this afternoon, dropping 2cm hail and 16mm in 15 mins outside of Melton. It also recorded a wind gust of around 95kph.

As for where I live - yet again, plenty of storm clouds, no rain and no lightning - i see why it gets frustrating - and I'm not even chasing them!

Big Pete

[Richary]

Channel 9 weather tonight said that the onshore winds and inland low is a classic La Nina weather pattern. With more heavy rain to follow and at least some more falling in the Murray-Darling catchment. Got to say I hope it eases it for at least a couple of hours in the morning, got to go up in a cherry picker for a repair job. If it is raining like it is now that won't be any fun!

[Harley Pearman]

Lets Look to the other side Monday 4 February 2008


Jimmy, when compared to the 1983/84 La Nina, and 1992/1993 event, both summers were very wet but not as hot as the previous summers. Especially the December and January period although I remember a higher incidence of thunderstorms occurring across the whole region during both summers. These wet summers followed previous drought years. The summer during a drought year is often very hot and dry.

That is, you had a very dry year followed by a wet year and the average rainfall would even itself out across the two or three years.

In the case of 1982 / 1983, the drought of 1982 saw rainfall drop to 393 mm at Albury where I lived at the time with 100 mm of that falling in March and very little thereafter until mid March 1983. The following year 1983 was exceptionally wet from mid March onwards and the summer was wet right through. That was a La Nina year. I remember 201 mm of rain falling in January 1984 although Autumn was quite dry that year.

The summer of 1992/1993 was also a wet year which followed on the heels of a dry summer of 1991/1992. Further, the very hot summer of 1986/1987 was followed by a cool wetter summer of 1987/1988 and temperatures did not reach 40 degrees once that summer.

The year 2006 was a dry year in that region and rainfall was as low as 213 to 270 mm. The year 2002 was a dry year and around 414 mm of rain fell. There was some recovery in 2003 but the first rains did not arrive until well into May that year. The year 2004 was OK.

After the past 2 droughts given that they were back to back, the region did not recover as well. The first 6 months of 2005 were exceptionally dry in that region although the last 6 months were wet with well above average rains. The great drought of 2006 set in from January.

The rains returned to most of NSW in 2007 but SW NSW did not see useful rains until June. Then there was no further rain until late October. Even then, falls were patchy and the region suffered rainfall deficits of roughly 20% below average by the close of 2007. That is, while the La Nina's impact was being felt along the coast and northern NSW, this region had no true relief until November 2007.

Incidentally, when looking at the drought figures and yearly rainfall deficits for February 2008, South west New South Wales is still in drought. Further:-

a) Average daytime temperatures for January 2008 were 2 degrees above average for southern NSW (Being about 33 degrees at least). For the rest of NSW, average January temperatures were 1 degree below average.

b) Far southern NSW and western NSW suffered a heatwave or near heatwave conditions in early January while temperatures struggled to reach 30 degrees in many areas coastal NSW or areas affected by cloud cover and rain.

c) There was 1 rainfall event in southern NSW that broke the heatwave about 2 weeks ago as I write this. However mid 30 degree temperatures soon returned thereafter.

This summer in southern NSW (Despite this La Nina) a trend has continued in which there has been 3 consecutive Januaries in a row in which daily maximum temperatures have been well above average.

A heatwave occurring during a La Nina event in southern NSW is unusual when compared to previous La Nina's.

The CSIRO has identified this region as being in serious trouble due to rainfall deficiencies and rising temperatures. Droughts also appear to be getting longer as well. While more research is required, whereas the previous droughts lasted 1 year followed by a wet year (Recovery), since the drought of 2002/2003, this region has not recovered as well given that there was a drought in the first half of 2005 (Rainfall was around 113 mm in 6 months), followed by the drought of 2006, barely any recovery in 2007 and now continuing into 2008. This region has missed out on many of the good rain events that has occurred elsewhere and dams are still at critical levels here.

I recently read a report prepared by the CSIRO regarding recent rainfall trends here and it does not look good. The drought statements and record keeping by the CSIRO and scientists are available for reading on the BOM website in the media section and the Sydney Morning Herald in the Environment Section. Makes for excellent reading on climate change.

Harley Pearman

[Jimmy Deguara]

Harley,

It seems you have provided a detailed explanation and drawn conclusions in response to relatively recent and short term La Nina events. I dare say that unless one draws attention to anything of the order of several decades of data, then one cannot conifidently conclude realistic trends in my opinion. I am surprised given you are much of a statistics buff!

Having said this, I would not mind checking the research you refer from the CSIRO. I am curious as to their trend analysis and what data time frame they draw conclusions from. Any links on the internet Harley?

Regards,

Jimmy Deguara

[Harley Pearman]

Jimmy

I will need to collect some of my notes and reports that I have collected especially during 2006 and 2007 while doing the climate change project at work. I will highlight these for you. Please note that it is an area under research and I agree with you that many years of data is required.

Maybe I should have made it clearer that this was an area under research.

In the 2006 Climate statement (I printed it out early 2007), it is stated that the dry conditions in southern and eastern Australia has continued the long term rainfall deficiencies some of which extend back 5 years. Aspects of this are highly unusual and unprecedented in many areas. Understanding this role is an area of active research.

Anyway a good starting point is the - Annual Australian Climate Statements that can be found at:-

http://www.bom.gov.au/climate/change/.

There should now be one for 2007 in the system but I have not read that one which should be the latest such statement.

Annual climate statements for each state can be found at Recent climate summaries and diagnostics, same website but found in the media section. I will need to track the important ones down and advise.

The Sydney Morning Herald at smh.com.au has an Environment Section and has run a very good section on "The Big Dry" up until recently. Click on the Environment Section and scroll through the media reports relating to climate change. There are hundreds now but I can do that and spend some time and post aspects here.

I am only too pleased to present information but I had no idea others were interested in this topic.

I have been following this drought closely and aspects of it are most unusual and it is worth presenting here.


Harley Pearman

 

[Harley Pearman]

Hello

I have found some data reports and notes of where I am leading to. I will list some of them and provide some discussions and conclusions found including websites.

Greenhouse 2007 National Climate Centre

CSIRO Greenhouse

The conference of 2 - 5 October 2007 and Accepted Papers and notes can be found at www.sciencealert.com.au

or

www.greenhouse2007.com/downloads/papers

The question sought is:- Can we link changes in ENSO to climate change.

The early findings are:-

a) There is little evidence yet of climate change signal.
b) Climate models do not consistently predict a systematic change in ENSO under greenhouse forcing.
c) There have been 3 El Nino's contributing to Australia's rainfall declines.
d) In the past, La Nina episodes have consistently provided good rainfall for Australia. The link between La Nina and increased rainfall is stronger than the link between El Nino and rainfall decreases.
e) Recent La Nina's have been weak or anomalous (Irregular) and have failed to counter overall downward rainfall trends.
f) Baseline Ocean trends have warmed over the past 50 years affecting rainfall and SST relationships.

Further

a) Heavy rain day trends in the MDB (Murray Darling Basin) have decreased from 1970 to 2006.
b) Droughts appear to be getting hotter.
c) Increase in temperatures may be attributed to greenhouse climate change.
d) Recent dry years to have warm temperatures than past dry years.
e) Water inflows are down.
f) There have been two, possibly 4 El Nino events with little recovery of rainfall between.

Current La Nina

a) Early signs were good in 2007 but winter rains failed. Inland - SW and west in the MDB shows below average rainfalls continuing.

b) Premature but there is a BUT emerging, "It is prudent risk management at this point in time to consider that it might be so" Quote.

It is concluded that there is a drying in the Murray Darling Basin and drought severity seems to be increasing. 

The CSIRO and BOM are researching the question? Is the recent Australian drought a sign of climate change?

Page 15 of that report (The paper) looks at rainfall recovery and there seems to be a downward trend.

The paper was prepared by Michael Coughlan, David Jones and Dean Collin (National Climate Centre) for the October conference.

I also found Figure 6 Australian rainfall impacts for some recent La Nina events and looking at the April 1998 to March 1999 large areas of inland SW NSW, Victoria and eastern South Australia suffered below average rainfalls too. This map series is from the report titled El Nino and La Nina and Australia's Climate (From www.bom.gov.au and dated February 2005).

IPCC Reports:

The IPCC reports provide limited detail on climate change. The Australian Greenhouse Office through the Australian Climate Change Science Program has engaged the CSIRO and Bureau of Meteorology to develop climate change forecasts.

The climate change report is available for download from the resources page. You should be able to get this at www.greenhouse.gov.au/science/hottopics/pubs/topic5.pdf

Special Climate Statement 14 Title - Six years of widespread drought in southern and eastern Australia November 2001 October 2007

The report describes the 6 year drought in the MDB exacerbated by high temperatures and low rainfall. It describes the anomaly occurring in the MDB (ie average rainfall 389 mm over 6 years which is 20% below the norm of 480 mm).

The report also describes a drought going back another 5 years in some localities and the lack of an intervening wet period. The report is noting the lack of wet periods to top up average rainfalls. This report comes with an illustrated map showing rainfalls deciles for an 11 year period from November 1996 to October 2007. It is noted that:-

a) South west NSW and parts of Victoria experienced below average rainfall or very much below average rainfall.
b) Much of northern Australia had above average rainfalls.
c) Eastern NSW had average to slightly above average.

The deciles include the 1998/1999 La Nina.

This report is published by the National Climate Centre and can be found on the BOM website. I have a copy of this.

A simpler article in the Sydney Morning Herald January 4 2008, simplifies much of the above so most people can understand it.  Titled "This Drought May Never Break".

This article briefly describes the issues facing the MDB, climate change and ponders the question as to whether the drought will become permanent.

There is significant research in this area and there are many related reports but I have not read them all. Too many and some are substantial. I also found other related material being:_

El Nino - Of droughts and flooding rains. Page 9 of that report written in 1997 hypothesises unusual phenomena with recent La Nina's at the time such as frequency. This was written in 1997 but it seems back then a change was starting to be observed in their behaviour.

Go to http://www.abc.net.au/science/slab/elnino/story.htm

Harley Pearman

[Harley Pearman]

Hello

Further to my previous posts on this subject, I found an interesting article in "The Age" Titled:-

VICTORIA LOOKS TO THE RAIN SOAKED NORTH AND AKS WHAT ABOUT US? Date - 11 February 2008

This article fits in with some interesting weather patterns and themes as previously identified and some story highlights are:-

a) Recent rainfall is showing that Australia's eastern states are becoming divided between the have and have not. Sydney and Brisbane are receiving so much rain but Victoria is still crying out for a good solid rainfall event.

b) Melbourne had until 11/2/2008, 12 mm for February and there are suggestions that much of the state will remain in drought.

c) Historically La Nina favours higher than average rainfall over eastern Australia which is occurring this summer (For much of NSW and Queensland) but Victoria is still awaiting for a persistent deluge.

d) A recent rainfall model suggests that there is no great chance of Victoria getting above average rainfalls.

e) Victoria cannot rely on La Nina to help out on it's rainfall deficiency.

f) Victoria could lose out on the flow on effects of the downpours occurring up north.

Additionally, some useful rainfalls did occur over parts of southern NSW and north east Victoria Tuesday morning however falls were patchy and good falls were isolated. Reading the Border Mail Wednesday regarding this rainfall / storm event, it was identified that the best falls missed the dams but instead several creeks flooded. Given that the best falls missed the dams and catchments, there would be little or no change on water storage levels.

Harley Pearman

[Peter J]

Thanks Harley,

Seems like this article backs me up, as rainfall in this part of Vic is well over 70mm below average for this time of year, and is abnormal for an La-Nina pattern, but then again, weather seems to never be normal.

Big Pete

[Peter J]

Hi all,

The last two days here in Eastern Melbourne has been sweltering and hovering around the 35-37deg mark. But there is some good news in sight. According to Wz and BoM, there is some moderate chance of rain tomorrow and through the next 7 days in the forecast period. 1-5mm expected for at least 3-4 of those days. Some relief for those of us here not lucky to get much rain.  And this is partly due to the moisture trail from TC Nicholas and an approaching cold front - the storm prediction though is very low.
We've only had 16.4mm of rain this month and 55mm overall (43mm at home) compared to the average of 103mm from 1/1 to 20/2.

Anyway, I hope all are safe in flooded regions around this great country - its great to know an old poem by Dorothy McKellar really does define this wide brown land - "...I love a sunburnt country, a land of sweeping plains...... of droughts and flooding rains" (Quote).

Big Pete

[Peter J]

February 20, 2008

Hi again,

Just updating the rainfall in Melbourne again.

Coldstream 2.5mm
Yarra Glenn  5.1mm
(Mooroolbark - 5.2mm in home gauge)
Melbourne 2.7mm

Not much, but the significant drop in temperature is marked:

Coldstream Top temp 21deg C
Melbourne overnight low 20deg at 5am this morning, top temp 22dec.

This is approximately 6 deg below average for this time of the year. And this is in comparison to the last to days of 36 deg and 34 deg respectively.

The outlook is for more showers with the flow on effects of ex-TC Nicholas and moisture from the Top End.

Mike - I hope the floods in NT's north arent affecting you too much for movement and storm chasing/observing. I also heard on the BoM, the system affecting you may turn TC shortly.

Big Pete.

[Peter J]

February 21st 2008

At least some rainfall yesterday brought a cool relief from the dry and heat experienced the last few weeks. Today was in direct contrast to yesterday. A fine and mild day throughout (although very warm later in the day) - also some Cu thunderheads were developing in the east of Vic (from my vantage point of Nunawading looking direct east), but were short-lived.

Keeping with Melbourne's theme of interchanging weather patterns, a vigorous set of cold fronts, preceding with trails of Ex-TC Nicholas will affect my region tomorrow, with a colder SWer change coming in (did someone invite winter in early??). The chance of some isolated storm activity may arise, but it will be storms synonymous with regular winter cold fronts - storms with hail (defined as COLD fronts for that reason - they produce BITTERLY COLD winds!), and may not produce any tornadic or gustnadic activity, but hopefully with my camera-phone, I may get a good chance to pic the front as it comes in, if it doesn't arrive too early!

Anyway, I will be away from my computer for a couple of days - house inspection (summer "spring" cleaning time - yuk!). But as soon as I can work out how to post the pics, I will share them with you all!

Happy storm hunting!

Big Pete

PS for those in NSW, this first of these fronts is expected to produce some storm activity in the south of your state sometime late tomorrow - keep an eye out. Also a severe wind warning (possible gusts to 90kph) has been forecast across a fair bit of VIC and S-NSW. Keep your hats on!

[Richary]

That cloud band from ex TC Nicholas (if that is what it is) has moved amazingly fast. But no rainfall recorded yet in SA - which could probably badly do with some.

Hope they get some rain soon down there. It was dry as when I left at the end of October.

[Peter J]

Hi all again, back on air.

The last 4 days have been in direct contrast with each other. Following on from my last post (Ex-TC Nicholas's influence on Vic weather), the storm system didn't have any bite when it arrived in the eastern area of Melbourne, but we did get a healthy 15mm (is it mm or ml - I thought water was measured here in ml's...anyone clarify?) of decent rainfall here - much needed by all here - the two days of rain here did bring unusually cold temps too - 19c and 21c respectively (7 and 5c below the Feb average). Since then, the last two days have been chilly in the early morning, but blossomed into wonderful sunny days of 23-24c each - it felt warmer at times today.

There were no thunderstorms here, not even a sniff of a CG bolt to be seen - waiting for the next Storm system to arrive (Melbourne Storm is back in March - watchout!!!)

Big Pete
(official Storm member 2008).