Topic: SA, NSW and VIC: Rain, storms and wind 2-5th September 2010

[Michael Thomas]

I think I thread should be started for this event. If my title is a bit broad, feel free to change it. It is just the system is quite large and will effect a large area.

First off, my main interest is thunderstorms which look increasingly likely across central and NE SA on Friday. Currently there is a nice tongue of very rich moisture in the NT extending into NE SA with due points of 17-20 C. A strong low-level jet should form in response to an approaching short-wave trough advecting this low-level moisture further south. With dew points in the high teens and temps around the mid-twenties, CAPE should be around 1000-1500 j/kg. With stronger heating, higher CAPE may be possible. Wind shear may be quite impressive, currently GFS has a 30 knot N'ly at 850 mbar along/ahead of the surface trough. Winds should be in the range of 50-60 knots at 500 mbar along/ahead of the trough. Lower-level winds should be NNE but may veer later in the day. This will, at least earlier in the day, result in reasonable turning in the lower-levels. If all goes well, the certainly should be sufficient shear and instability for supercells with large hail and damaging winds. The strong low-level shear may suggest the potential for tornadoes if the storm bases are low enough and a supercellular storm mode dominates over more linear convective modes. I don't want to hype that up though. I hope I haven't jinx it and I wish there was a radar further north in SA.

Michael

[Michael Bath]

The rain part of the event looks to be quite significant with flood watches now issued for large parts of SA, NSW and VIC.

Pity the thunderstorm setup is in no-man's land!

[Taipan]

Really looking forward to observing this event from here in Vic, and hoping to get some filming done.
The synoptic chart for Saturday looks amazing with the deep low right over western Vic.
Hoping there might be a few thunderstorms embedded in this system.

Cheers all,
Chris.

[Harley Pearman]

A cumulative rainfall plot for 2 to 5 September 2010 is attached below (From BOM Land and Water - Rainfall prediction) showing possible rainfall. Models are showing the best falls to occur across inland New South Wales, Victoria and especially North east Victoria, South West Queensland and South Australia.

There are flood warnings in force for the King, Kiewa, Upper Murray (Above Hume Reservoir) and Ovens River. Overnight 1/9/10 isolated falls of up to 30 mm occurred along and close to the highest peaks of Victoria such as Mt Buller, Falls Creek and Mt Hotham. Similar totals occurred on and near Mt Kosciusko which has wet the catchments. This event should follow on from that overnight rainfall. Either way river rises may occur across NE Victoria should the heavy rains unfold.

The cumulative 4 day model suggests that the East Coast of New South Wales, Queensland and eastern Victoria should receive much lighter falls.


Harley Pearman

[Michael Thomas]

Looking quite interesting at moment. The Woomera sounding this morning has to be one of the better soundings I have seen from Australia. That said, I don't really know if the storms can really make the best of this environment. There are a couple of strong storms right near Woomera now at the southern end of a line of storms, not really the ideal location. Also, with the speed at the which these storms are moving they will probably move into a cooler, more stable air mass pretty quickly.

[Michael Thomas]

Unfortunately those strong storms near Woomera have weakened. Still some pretty strong elevated convection down around Adelaide. Pretty impressive obs further north, 24/20 at Marree with at 50 km/hr NNE'y. It would appear, however, that surface based storms have not yet established themselves up there yet.

[Hardy25]

looks impressive might have to take the camera out if anything starts to look really nice

yay for spring =]

[Antonio (stormboy)]

holy hell this system is huge!

i cant believe how thick and large this cloud is and also heaviest rain in 15 years!

THE biggest storm in 15 years is expected to hit Victoria tomorrow.

Emergency services are braced for torrential rain, fierce wind and flooding that could affect thousands of people.


Residents in isolated areas have been warned to stock up on food, fresh water and medical supplies amid fears the wild weather could cut major roads and flood low-lying regions.

Parks Victoria has urged visitors to reconsider weekend trips to national parks and forest areas with the chance of landslips, falling rocks and swollen creeks.

"Rivers, creeks and waterways can rise very quickly," DSE spokesman Mark Woodman said. "People should not camp close to waterways or try to walk, ride or drive through flooded areas."

Melbourne is likely to miss the worst of it, with a drenching of up to 15mm, but the Wimmera and Mallee are facing a deluge of up to 150mm and fierce wind.

Weather bureau forecaster Claire Yeo said: "The expected heavy rainfall across Saturday and Sunday will be the heaviest in one event for nearly 15 years."

Flash flood warnings have also been issued for the north, north central, northeast, and alpine regions.

Weatherzone meteorologist Martin Palmer said it would be nasty.

"A rapidly deepening low pressure system, currently over South Australia, is bearing down on us and will bring some very wet and windy conditions over the next 24 to 48 hours," he said.

"Over South Australia, continuous rain has already brought some of the best early spring rainfall in over 10 years."

The low is expected to move south and east today, pushing the storms into Victoria.

"This low is really going to turn a bit nasty during Saturday and deepen as it heads into western Bass Strait," he said.

"As it moves to the south the wind will whip into the southwest and drive into western parts of Victoria, with potentially damaging wind gusts above 100km/h possible."

He said the strongest wind would develop late today and move through the state during the early hours tomorrow.

a few links

sattelite -- http://realtime2.bsch.au.com/ir_sat.html

Bom past 24 hours or more radars -- http://www.theweatherchaser.com/radar-loop/

BSCH precipitation -- http://forecasts.bsch.au.com/apf.html

Antonio.

[Kristy Norman]

Well....things are not pretty here this morning to say the least.
 
This wind is absolutley roaring and rain has just started to really bucket down.
17 mm of the wet stuff here since midnight and if anything it is just getting heavier.

There is the chance of thunderstorms to come across a bit later but they will probably only be embedded in this messy rain.
Not a very nice day....

[Colin Maitland]

It is a very intense low pressure system as can be seen from the Sat pics. It is expected to deepen as it moves East. Southern parts of NSW and the Central Tablelands should feel the brunt of it today with very strong winds and heavy rains.

Looking at the radar yesterday it was quite an impressive squall line and storm system that moved across SA. It appears to be a Bow Echo on the radar, although I not sure what the wind gust were at its peak. Would have been interesting to see photos of the front as it moved across.

At the time of this sweep the main storm system was to the East on the SA and VIC borders.

[Hardy25]

any updates, anyone out following any of the storms

im stuck at home this weekend, would love to hear of anything =]

its close to 5pm if anything was to happen would be now

[Antonio (stormboy)]

well if you have a look here http://www.weatherzone.com.au/news/ there is soo much happening.

weather wise here WINDY is the word my station has been at 50km most of this afternoon 54km was the maximum so far today.

looks as if the cloud is slightly thinning out.

Antonio.

[Hardy25]

well if you have a look here http://www.weatherzone.com.au/news/ there is soo much happening.

weather wise here WINDY is the word my station has been at 50km most of this afternoon 54km was the maximum so far today.

looks as if the cloud is slightly thinning out.

Antonio.

Thanks For That =]
but im a member already, was really more wondering if anyone was out on the road chasing and taking some photo's
and i thought if any storms were going to start popping it would be from now onwards
but thanks for the reply =3

[Karina Roberts (slavegirl)]

Anyone got any clues as to when the system will arrive in SE QLD? On weatherzone they are prediction a chance of a t/storm at 3am and the radar/lightning tracker shows a nice line west of toowoombah, hoping there is a bit of lightning activity a bit earlier than 3am lol looks nice and dark out here and still pretty humid

[Kristy Norman]

Some isolted very heavy showers about this afternoon here.
The wind has been absolutley bonkers, plenty of trees down.
38mm so far just today, and it's still teaming down.