Topic: NE NSW/SE QLD Storms Saturday 22nd September 2007

[Michael Bath]

This has been on the cards a few days now. The latest GFS run is favouring the tablelands west of the Northern Rivers and Brisbane for Saturday afternoon and into the evening. The quite cold temps forecast at 500hpa (-22) should help to assist with storm development given the surface convergence along the ranges. The southerly should lift the DPs enough but then we'll have cooling temps.

Michael

[Shaun Galman]

G'day Michael,
I surely hope you guys get something out that way! No luck for this regions forecasts as yet, still dry hot and dusty lol. I heard that the bureau are not expecting anything in the way of decent rain until the end of October sometime? I hope this doesn't include storms, isolated or otherwise, that would be a crime!

Best of luck if you get to chase!
Take care.
Shauno

[Jimmy Deguara]

Hi Michael,

I am not enthused by the latest 00Z run with either numerous storms or a rain event from this situation. Time will tell - it certainly can be expected to be quite cool tomorrow! A very cold southerly surge. Wind shear aloft and also at the surface is nothing short of crap!

Defintely not chasing this lot.

Regards,

Jimmy Deguara

[Steven]

Ha ha, I've heard enough.  I did mention on WZ about it being too dry, and it is still too dry, results will be like last week sort of, although colder upper level temperatures doesn't necessarily mean anything, it just means colder temps and more of a chance of hail. But since this was first on the cards I wasn't expecting much anyway, noticed that the Bureau have upgraded their forecast for a "shower or thunderstorm late in the day" that in itself sounds encouraging after it was only "possible" earlier, but I'm still iffy about it.

[Jimmy Deguara]

There will be storms, I am just not forking out fuel for something so distant and so low key of an event. The atmosheric set up is probably more ideal for the tablelands initially and mid level clouds will certainly become widespread. I am not a fan of mid-level cloud and moist air aloft.

There could be a waterspout or two off the coast.

Regards,

Jimmy Deguara

[Steven]

Quite a few lines of storms now, the biggest one is just passing out to sea from Coolangatta to southern Brisbane areas. More is forming. Should intensify after dark I presume. Although the Bureau have canceled their warning, it shouldn't be long before they re-issue it. Definitely optimistic about this.

[Jimmy Deguara]

Steven,

Although the Bureau have canceled their warning, it shouldn't be long before they re-issue it. Definitely optimistic about this.

Don't you think that loss of daytime heating as well as a cooler boundary layer is going to decrease prospect of severe storms? I think the severe storm warning for "possible severe hail" was marginal at best. The storm apparently looked crap - low topped.

We have to be careful when suggesting that warnings will be re-issued - that is a job for the Bureau of Meteorology.

Regards,

Jimmy Deguara

[Mike]

well somebody should jump in their car and see what all the fuss is about - what about that Audi we saw in previous threads - no hail so chase in that!

Mike

[Jimmy Deguara]

A warning has indeed been re-issued but the main concern looks to be very heavy rainfall. Hail like in SE Qld is a marginal chance at best but we'll see how the reports come in.

Regards,

Jimmy Deguara

[Steven]

Well there is some explosive development at the moment, they are just popping up in about 10-20 minutes, one particular at Redcliffe right now. Jimmy, I do agree with you about the severe thunderstorm possibly regarding heating, but we'd take anything besides I always knew storms weren't going to be much more severe than some torrential rain and maybe some high wind. Speaking of that, it's quite cool here, but there are dark skies and some mammatus formation around, I think judging by the patterns of cloud. Mammtus is a warning sign usually.

[Steven]

Quite a bit of activity off the coast at the moment, bright lightning and some echoing thunder, from some activity that cleared the coast an hour or so ago, quite impressed actually. Heavy rain as well although no hail, more storms are coming up from NSW.

[Jimmy Deguara]

Steven,

http://Mammtus is a warning sign usually.

Mammatus are not only associated with severe storms but also cold air cumulonimbus and also altostratus.

It looks as though the storms have developed into a rain band complex so some useful rains up that way.

Regards,

Jimmy Deguara

[Michael Bath]

Was out and about in SE QLD after the ASWA meeting and there was nothing impressive unfortunately. Initially high based and low topped but they were developing quite quickly in some places and soon producing heavy showers. Towards evening (and now in the northern part of the Northern Rivers) tops were getting higher and lightning increased but it was turning into a rain areas then. Stratus had moved in from the SE too. Rodney and I saw one amazingly impressive pulsing CG associated with with a widespread anvil crawler near Kyogle. After that it was the odd flash of lightning imbedded in the rain.

27mm of rain at my place in a couple of hours early to mid evening was very nice. Over 100mm in a couple of hours in the Coffs area was the reason for the flash flood warning for the Northern Rivers.

regards, Michael

[Michael Bath]

An isolated storm developed just north of Warwick at 8pm and dumped a lot of hail just east of Allora. Photo by Anthony Cornelius

The Brisbane sounding shows the upper levels cooled by 6 degrees in 12 hours as the upper trough moved across. This was pretty much forecast by GFS.

Brisbane 12z

I've included both Brisbane radars as the high-res Doppler decided to crash AGAIN mid way through the storm.

Brisbane radar loop

Staplyton radar loop

Looks like we should not have left our chase target (Warwick) though it was pretty crap there during the afternoon. Would have had to sit there for another 4 hours before this storm developed.

[Michael Bath]

ABC News report


Hail takes toll on Darling Downs' crops
Posted September 24, 2007 12:12:00


A hail storm on the Darling Downs, in southern Queensland, has damaged fruit and vegetable crops.

Some properties were blanketed with ice.

The storm hit on Saturday night.

Cliff Walker from Rockmount, south of Toowoomba, says it hailed for 20 minutes, destroying his tomatoes and knocking flowers from other crops.

"About the size of marbles or a little bit bigger, fairly round, not much jagged stuff in it, just the amount of it that did the damage around here, it was fairly thick," he said.

Weather forecaster Ben Annells says the storm followed the range north from Warwick and was not classified as severe.

"Being the time of night the most it could do was produce a lot of small hail which can be quite damaging anyway," he said.

The weather bureau says the storm produced good falls over the catchments, including 30 millimetres in the Wivenhoe area.