Australian Severe Weather Forum

Well, may as well open a thread now. Looks quite interesting as it stands, Friday in particular -- a very broad area or moderate to strong instability under the nose of very strong mid level jet, and monster upper level flow with virtually the entire state of NSW under > 80 knot winds.  Will be worth watching this, even for us hapless souls in central eastern NSW who have discovered a new frontier in abject stormlessness.

Thursday is the 'day before' here in Sydney, and history tells us that it is very often a good chase day. Stay tuned.

While on Thursday, the current GFS run has a shear profile conducive to tornadoes, possibly strong tornadoes in the area around Woomera in SA around peak heating. Forgetting about the thermonuclear CAP and possibly too-high dewpoint deficits that is. This is a very dynamic system, things will change, but this really could get quite exciting.   

currently for SA >> [attached image]

I must admit that the thing I like about the the coming setup is the wind shear. For those based in Sydney/Illawarra Friday appear to be the big day with a modest kilometre trip west of the divide.

At this stage only the surface wind is lacking, but if we can get 15-20 knots out of the north we may see some 'supercell' potential here in NSW too.

Still early days and the models have been jumping around a little.

Great to see the possibility of storms just when I finally arrive back to Australia. This system certainly is something to watch but going by GFS currently things are not quite right. I would agree that the shear in SA looks quite spectacular but I would think that LCL's will be way too high if GFS is to believed. On a side note, here in New Zealand, there was an amazing shear profile in the evening over the north island with NE surface winds, a 50-60 knot N'ly lower level jet being over run by a 70 knot NW'ly mid level jet. Shame there was no CAPE due to lousy lapse rates!!

Michael

My forecast based on latest runs is looking like Albury to Canberra having a high risk of supercell development, with a near certainty for severe development. CAPEs without added surface heating progged to 1500, LIs up to the 6's, and more than decent shear. If the moisture profile holds we could see some really explosive stuff with large hail, given the trough and cold at 500hPa....depending on how the moisture goes im guessing more likely to be classic to LP if they form. And to top it all off Ive chosen tommorow night to leave for Perth to see the fiance....ahhh how it teases me with these conditions. 

I'm staying with my family until Sunday who live 80km north west of Albury. 
Ahhh....the anticipation!!!!
I can't wait to move back here in January as we don't very often get any ripper Summer storms over on the west coast. They develope inland just far enough away to tease until the seabreeze comes in and pushes them away.
Bring it on!

David, can you update on how things are looking in your opinion for the Woomera area and nearby for Thursday?
Main reason being is that I am on holidays atm, and if its worthwile I might head up that way.... it would obviously have to be worth it for the drive...

Hi guys,

The region around Central and Southern Victoria looks half decent for severe storms this afternoon (26th November 2008) if moisture is able to penetrate. I think there is a good possibility of low level rotation as often occurs in these cases when these conditions occur with north east winds tending to northerly to 850hPa level. One to watch anyway especial if any chaser can chase along the surface boundary. Yes the upper level support may not as strong as we would like but that does not rule out storm scale rotation.

Regards,

Jimmy Deguara

Tim, as you would probably agree, you would have to be very keen to go for a drive given the distances involved.

LAPS looks very hot and dry over SA for the most part, and given that GFS performance has been the worst I have ever seen it this year, especially regarding boundary layer moisture, I would expect that to be the case. Both models develop surface low pressure in WA through weds, but 12z GFS progs an elongated low thurs with a reasonably impressive isallobaric response with deep and solid NNE infeed, around 20 knots, and moisture advection contributing up to and around 2000j/kg convective energy during the late morning (of course GFS is most probably pulling those numbers out of its backside).

With LAps moisture basically does not get in to SA except western border. Whatever model you choose, through the afternoon though, intense heating and mixing come into play and makes the situation worsen.

I think there will be some interesting storms around, and it is worth watching. Incidentally, going by mesolaps just now, the best chance for tornadoes would be in the strongly backed flow near the coast around Eucla, or thereabouts. The LAPS shear profiles progged for that area are very impressive during the morning and afternoon, although moist sfc parcels have a cool marine origin.

Still looking ok for further east across NSW at this stage for Thursday and Friday.

  

Some interesting cells over N inland NSW and S inland QLD now (3pm-ish 26/11).

The Moree sounding is nice - good lapse rates and shear and an ideal moisture profile. Main downside will be the low topped nature of storms.

Hi guys,

MB: I'm just keeping an eye on the line of storms that are currently between Bourke and Brewrrina on radar. They seem a little further North than I would like but it's early days yet :D

We are still well in the BoM severe storm warning area at this point.

I can't quite see anything here as yet except the isolated Cu's. I wish I could get out onto one of the high west facing ridges for a better view? I'll definitely keep an eye out though.

I can actually get out there now as I finally have the clutch plate/gear box fixed in the Nissan. I'll be mobile once again! :D
Temps are up, pushing 36ºc currently and humidity feels high (no current observations available for us on the BoM for some reason?)

Kindest regards,
Shauno

Very severe cell heading into Wee Waa now (~11:00 UTC).

It's a long lived cell which has come all the way up from the far side of Coonamble. Looks like a hook echo for several RADAR frames. Very heavy core. From Narrabri I can see flashes about every 3 seconds.

Comes on top of a storm earlier today which apparently dropped substantial hail on Wee Waa.

Thanks for your thoughts David... yes after doing 3500 kms roaming the NSW countryside last week for storms (must get some pics & report up), I'd have to say I dont really feel like another long drive... I'm hoping we might see at least 1 or 2 storms come a bit closer to Adelaide in the next day or 2 but wont be holding my breath!

Despite me getting some decent storms in the Wee Waa/Narrabri area this time last week, it still annoys me greatly when you see what they got today and atm.... Some very good chasing territory out there at Burren Junction where that red core is just going through!!!

Also golf ball sized hail and damage at Coonabarabran around 5.30pm, and wind gusts up to 113km/h at Moree just after midnight. I'll do up a radar loop. One of those afternoons to be on the Plains !

We just got emailed a report from Wee Waa mentioning hailstones "like ping-pong balls, no exaggeration". The report said that even trucks have dents in them.

Namoi Cotton's AWS at Yarraman a little west of Wee Waa registered about 45mm between 10pm - 1am.

Today is looking not too bad for storms around NSW and Vic (also SA as well). Just a shame the dp's are so low. It is rather unfortunate this system is moving though so soon after the recent cold/dry weather. Along the east coast, shear is generally very good with deep NE low level flow with strong mid/upper level flow. The deep NE low level flow is resulting in excellent moisture depth (from the surface to almost 800 mbar on the morning sounding for Sydney). The air aloft is very cold for this time of year (-16C at 500 mbar in the morning sounding for Sydney) which will result is some modest CAPE even with the low surface dp's. With some luck we will see a decent increase in low level moisture during the day and hopefully a few nice storms in the afternoon as well.

Michael