Australian Severe Weather Forum

Well...Its about time a thread went up for the passage of this trough system given the moisture present throughout eastern Australia.

Wednesday: Isolated thunderstorms in Western Victoria with a small chance of organisation. Scattered Cbs across the ranges with O.K LIs. In NSW looking at Bathurst region for Isolated thunderstorms. Northern Rivers chance of a late storm, SE QLD isolated thunderstorms.
My target will be lightning on the ranges NE of Melb tonight.


Thursday: Scattered Thunderstorms for western Victoria, and Scattered across the ranges, possibly severe with the shear. Plains action accross the Albury Wodonga region...low chance of organised storms. LIs down to -4 near bathurst and west of Mudgee, and for this reason im going with Thunderstorms with Moderate to high possibility of severe/organised.
Won't be chasing during the day due to cricket training.


Friday: Action begins to contract into NSW, High possibility of severe and organised storms over Mudgee region and fair chance of isolated CBs for Sydney. In my opinion i'd be pretty sure severe storms with possible supercells on the western slopes if the moisture holds given the shear and good LIs.
Likely will chase for the western slopes.

Saturday: If there was a day to chase the northern rivers this is it...unfortunately cricket prevents me.
CAPE up to 2000 over the region, LIs to -5, shear moderate. Id be even more certain of a supercell or more, with a high probability of severe weather for the region. Not sure on storm direction or topography but Id be setting myself in Armidale to get my bearing off the Cu fields. Im fairly sure that Coffs and Lismore will also see action as the storms move towards the coast.



Anyway...thats my brief and scattered forecast for this event.

Thanks for starting this thread John. I was going to wait another day to have a go at it but you beat me to it. Saturday looks to be the pick for some action for us here in the Northern Rivers. GFS on BSCH has been pretty consistent in its CAPE forecast for the last few days, so I'm hopeful we'll see something. If any cells do get going they'll generally move in a ENE direction with maybe an isolated cell or two moving more NE'ly. There is a NE'ly at around 10kts at the surface backing to a SW'ly at close to 15kts at 700mb and a W'ly at 20kts at 500mb. Interesting to note there is a 180 deg of turning between the surface and 700mb. Overall the shear doesn't look overly strong but conditions on the day may vary from the forecasts. I'm hoping moisture isn't going to be an issue (again) as we've had some good numbers for storms recently, only to be lacking in crucial moisture. I've pulled most of these numbers off the forecast sounding on BSCH (I know its only a forecast) so its possible conditions on the day could turn out to be a lot better or a lot worse, I guess only time will tell. On another note the forecast temp for Saturday atm is 32 deg, but with the 850mb temps hovering between 18-19 deg is it possible we'll see temps exceed those forecast? If so things could turn out to be a bit more interesting.
Its been a while since I've had the opportunity to chase so I'm itching to get out and see some stormage. Got my fingers crossed we'll get a rumble or two.

Cheers Jason

Localised wind damage in Melbourne's inner west:

Well there were no storms in or around Melbourne today and not much wind either - but none of that was a surprise, although the moisture and heat here today was pretty oppressive.  What was a surprise was to get home and see the news showing very localised structural roof damage to a large warehouse in Footscray, only a few km's from the city.  Of course they used the term 'mini tornado'.  Apparently brief but very strong winds mid arvo broke and tore sheets of asbestos cement roofing and wall sheets off the building and scattered asbestos debris around the area.  From the brief chopper news camera view it looked to be at least 10m2 of materials had been dislodged.  I know from my employment that AC sheet, particularly the corrogated roofing is a strong material and although it can be broken, it is unusual for this to occur due to wind, especially on a day that is not even windy!  I have searched for more details but havent found any yet.

Now I've heard of and seen powerful downbursts, microbursts and the various vortices associated with serious convection, but at this time of day all I observed to the west of the city was a mid level shallow cumulus field.  Any suggestions for what may have caused this brief event???

This seems to be most likely a stronger dust devil or if there were a few cumulus around perhaps a landspout. Were any pictures taken?

Regards,

Jimmy Deguara

Hi Jimmy, im not aware of any pics of the event itself and other than the news clip I saw, I cant find photos of the damage so far.  Perhaps the late news may have an update. I will keep an eye out. 

Moisture copped a hiding just before 12...station data indicated we went from surface DP at 12 to 1s. Surface heating was good but unfortunately surface layer too dry to provide enough oomph for decent convection.

Found this story on http://au.news.yahoo.com from ABC news:

A factory was evacuated when strong wind gusts tore off its roof in the Melbourne suburb of Yarraville this afternoon.

Eight panels of corrugated asbestos sheeting flew into the air and crashed to the ground in the car park and surrounding streets.

Witnesses described the winds as a "mini tornado".

There's that rotten term again (urgh) - "mini-tornado" - just another non-cloud wind event! They do happen in this state.

Big Pete
(sic of the mini)

Apart from that......

The weather is very hot in Vic at the moment - and the cloud levels have increased this morning - I though late yesterday a storm or two might have developed - at least they tried to, but no success. Today is more likely - the humidity levels are opressive, and there is a lot more Cu about at the moment - from my vantage point at Nunawading at 6.30 this morning looking west - I did see about 5 to 6 small towers forming. Also the radar on wz is picking up storms out to Bass Strait near the Bight interchange. Also the wind here is very strong (bad fire risk) - gusting around 40-60kph.

Hopefully it doesn't rain before 5pm, so I can still get some work in (need to boost the hours).

Big Pete

Hi guys,
It's great to be back online once again, and I'm broadbanding finally lol!

Looks like things may kick off weather wise for us over the next couple days, well.. at least a small chance until Tuesday, given the synoptic outlook on WZ?
The convective map shows possible storms for us tomorrow (possibly late tonight?) with the encroaching trough. I'll be ready and waiting :D

Ahh what a relief to have access to charts again!
Take care! (I now look forward to going back through the forum and viewing all the youtube links that were posted!)
Shauno

It now looks like we can throw Sunday into the mix now for a possible storm or two. GFS forecasting some good CAPE again throughout the region, with it being a touch better than Saturday. Looks like a nice stormy weekend coming up.

Well I think tomorrow is actually looking somewhat interesting. With the forecast high temps I am a little worried about moisture, we could see some rapid mixing out, ie dew points dropping like a stone when the day heats up. Having said that, the Williamtown sounding show decent moisture depth (moist in the lowest 100 mb, although dp's are a little low). Having a look at the current obs shows dp's in the 16-17 range along the coast. Shear is generally quite good in the Illawarra and South coast and more than sufficient for severe storms, including supercells. I would say if moisture holds in place there should be some nice storms. Here's the forecast sounding for Norwa plotted at 30/17-

http://soundings.bsch.au.com/skew-t.html?source=ncep&lat=-34.9&lon=150.6&gribdate=2008111300&hour=06&month=11&day=14&year=2008&t=30&dp=17&mixop=usr

Maybe thats a little optimistic but well see. Also there will be the S change moving up the coast in the South Coast which may trigger something down there.

Michael

Been waiting for the storms - but yet again, they fail the eastern Melbournians.  Been less than a mm in the gauge in the last hour (8-9pm). But one thing for sure is the oppressive heat may finally be getting ready to lift - and some cooler weather is expected here for the next few days - still think storms may (optimistically?) occur overnight whilst I'm asleep.

Maybe might get some tomorrow - but i'm not counting chickens yet

(a very disappointed) Big Pete

Well Big Pete we did get storms.  I just got back from a great night of lightning photography with John Allen at a spot I found north of the airport with western views.  There was lots of lightning including some very bright CG's and some elusive crawlers.  It was great to hear thunder again!  Will post pics tomorrow.

As will I...but mine arent in Brads league. Seems my filter isnt helping much...will have to try without it next time.

Well maybe I should never speak too soon. As of 6.30am this morning, I was greeted at my work with a beautiful crawler followed by a long rumble - plus a nice deluge of rain followed!

Will post some pics later on when I find a way of downloading them from my new phone to my computer.

(missed out on the crawler pics but....)

Big Pete