Topic: QLD and NE NSW rain event 18- 25 sept 2010

[Colin Maitland]

After observing the GFS runs and other models over the last few days, it appears that we could once again be in for some large rainfall totals in QLD and Northern NSW.

The temps over the next few days are expected to remain low due to the heavy cloud cover, which is adding to the diminished chances of storms for another week or so, thus adding to the SDS that many of us are experiencing.

As we realize the runs of the GFS constantly change but I expect to see at least 50mm+ once again. The latest posted run has some exceptionally high total which Iam still not 100% confident in, but never the less the potential is there for some localised flooding.

BOM latest forecast run is showing similar high falls around the 22/09/10 -25/09/10

Colin

[Antonio (stormboy)]

there looks like there could be a possibility of a rather large rain event over the next 5+ days. weatherzone states

Queenslanders should prepare for a wet week ahead.

By the end of next week parts of Queensland, including Brisbane, should have September rainfall totals exceeding the wettest in over ten years of records.

Brisbane has already exceeded its average September monthly rainfall total and is set to be deluged with a seven day rainfall total potentially exceeding 100 millimeters.

Queenslanders in the interior and east may need umbrellas and gumboots thanks to the persistent rainfall that is likely to last for well over a week in the "Sunshine State".

Isolated coastal areas could receive 24 hour rainfall totals exceeding 100 millimeters, providing a flood risk is parts.

The rain event can be attributed to a series of troughs that will create atmospheric instability over the coming week. Moist air will be delivered by onshore winds and tropical air that will filter south.

Above average rainfalls are likely to continue throughout Spring thanks to the expected continuation of La Nina type conditions.

La Nina conditions are generally associated with an increase in convection, cloudiness and an increased probability of rain in eastern Australia.

Attached below is the rainfall outlook on BSCH and it looks impressive for large totals.

Antonio.

[Colin Maitland]

Showers are increasing this morning as I post this. The best total to 9.00am this morning was recieved at Blackall with 39.6mm as at 7.07am.

Yesterday at 6.06pm Douglas Fenton from WZ News reported that Brisbane could expect record breaking rain this week,
He stated: By the end of next week parts of Queensland, including Brisbane, should have September rainfall totals exceeding the wettest in over ten years of records.

Brisbane has already exceeded its average September monthly rainfall total and is set to be deluged with a seven day rainfall total potentially exceeding 100 millimeters.


The GFS runs are still calculating large totals of over a 100+mm with some areas around the 200mm. It will be a wait and see what the final readings will be. But a wet week is ahead for QLD and Northern NSW

Colin

[Antonio (stormboy)]

if this rain event is any like what we had along this area 2 years ago the coasts will receive very high totals, usually even when a normal rain event is around our coastal regions always receive more falls more often and sometimes more heavier.

Antonio (no rain yet but it is spitting)

[Karina Roberts (slavegirl)]

No rain out in Beaudesert yet (radar shows rain but it mustn't be reaching the ground) but it will be very interesting when the rain does arrive (especially if its alot) as we have quite a number of low lying roads and floodways around the town especially on the back roads out to biddadabba and wonglepong. Might be some good photo opportunities when the rain starts out here

karina

[Michael Bath]

"biddadabba and wonglepong" - what amazing names

There is/was a rather dry layer in the lowest 1.5km of the atmosphere over SE QLD going by the Brisbane sounding (attached). That would be a bit hostile to much precip reaching the ground, but when that mixes we should get 'proper' rain. Only 0.5mm here so far.

MB

[Antonio (stormboy)]

not too much happening here at the moment only 0.3mm although humidity has been rising very quickly and it is very dark here so maybe more rain on its way.

the wind is also very still.

Antonio.

[Colin Maitland]

Most of the rain has been over the central interior of QLD.

 BOMS update at 3.50pm

Heavy rainfall over the last 24 hours has led to river level rises along the
Thomson river and tributaries upstream of Longreach and the Barcoo River and
tributaries from Tambo to Retreat. Some minor flooding is likely overnight
tonight and through this week.

 
Upto 117mm has been recorded in the Thomson and Barcoo River catchments in the
36 hours to 3pm Sunday. River level rises have been recorded at Bowen Downs on
Cornish Creek and at Blackall and Retreat on the Barcoo River. Some minor
flooding is likely this evening and through the week in both catchments with
further rises likely with continuing rainfall.

Rainfall totals in the 36 hours to 3pm include, Bowen Downs 58mm, Gue 69mm,
Blackall 117mm, Duneira 112mm, Isisford 52mm and Retreat 38mm.

Colin

[Karina Roberts (slavegirl)]

since it started raining this afternoon early evening we have had 5.6mm rain and its starting to get heavier it has also droppeed down to 13 and feels like the temp may drop lower later on tonight

[Michael Bath]

13mm at my place overnight though nothing more than light rain or drizzle.

The central north QLD coast is having fun this morning with a STW for flash flooding in place for areas between Rochhampton and Bowen. The profile as shown on the Townsville sounding last night is perfect for slow moving or training thunderstorms and very heavy rain. Note how the winds back with height up to 550hPa and it's unstable all the way to virtually 45,000ft

A location around Mackay has had 87mm in the past hour.

[Colin Maitland]

It is interesting to see that 107mm of rainfall was recorded in 2 hours at Gooseponds.


Some of the rain totals for Whitsundays/ Mackay area as off 8.25 am

Hospital Bridge AL     124mm
Mackay AWS *       75mm
 Mackay Airport AWS *    30 mm
Mackay AL *       132 mm
Rowallan Park AL    88 mm
Gooseponds AL           152mm

Roma Peak AL        60 mm
Reeves AL *       101 mm
Bowen Pump Station AL * 81mm
 Bowen SYN       84mm

 
The storm warning from BOM that MB was speaking about is:



SEVERE THUNDERSTORM WARNING
for FLASH FLOODING

For people in the
Central Coast and Whitsundays and parts of the
Capricornia Forecast Districts.

Issued at 6:54 am Monday, 20 September 2010.

Severe thunderstorms are likely to produce very heavy rainfall and flash flooding in the warning area over the next several hours. Locations which may be affected include Mackay, Proserpine, Bowen, Yeppoon, Hamilton Island, St Lawrence, Sarina and Eungella.

107mm of rainfall recorded in 2 hours at Gooseponds Alert near Mackay ending at 6:45am.

[Antonio (stormboy)]

Rain to 9am Today got to 9.8mm and so far only 1.4mm there is a rather huge cloud band over QLD coast and is moving southwards, anyone think it will make it as far south as the NR?

Antonio

[Steven]

I think it might slip off the coast overnight or tomorrow but not before heavier falls in the SE region. It does look like the bulk of the rain will move down towards the SE and gradually weaken, although it should continue to be cloudy, rainy and cool for the remainder of the week (hence bumping up the rainfall totals).

Locally, we've had an unimpressive total of 8.6mm to 9am.

Oh and BTW, those BoM rainfall maps seem to be far more accurate than GFS. GFS is notorious for over-exaggerating forecast totals.

[Antonio (stormboy)]

a little bit of rain has been falling since 2pm with nothing showing on the radar so it must be very low level.

27.6MM from 9am to now.

UPDATE() from yesterday to 9am today we had 38.7mm of rain it has not rained for about an hour now.

below is a image of the graph my weather station has been logging you can also check for updates at my website http://www.ballina-nsw-weather-from-stormboy.com/trends.htm and click on rain today thumbnail.

Antonio.

[Colin Maitland]

Queensland's central districts have seen their wettest September since records began and we still have 8 days of the month remaining.


Springsure collected 232mm so far this month, that's the largest September rainfall in 145 years of records.

Tambo had 146mm so far, breaking the previous September record of 131mm in 1906.
This months total makes it the wettest September since records began in 1877.

As stated before, the rain is not yet over. The next few days could see the Central West, Central Highlands and Maranoa districts collect up to 50 to 75 millimetres.
Looking on the radar earlier this morning, it was showing some good showers over the lower central coast.

The highest recorded rainfalls in the last 7 day period in QLD, have been :
 Mackay        223 mm     East Central Coast
 Babinda       198 mm     Barron
 Cardwell Range    158 mm     Herbert