Storm Australian Severe Weather Forum
Severe Weather Discussion => Australian Severe Storms, Weather Events and Storm Chasing => Topic started by: David C on 09 September 2007, 06:04:49 AM
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Upper trough coming through, low level moisture looks set.
Discuss.
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GFS is playing around with the timing a fair bit and the BoM seem to think it will be westerly change based on their current Northeast NSW district forecasts. The latest GFS run suggests the trough will arrive too early for the Northern Rivers on Tuesday. Should be some action Monday 10th inland too.
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From when I looked at the models, the whole event has been downgraded in being mainly off the coast. Monday is extremely marginal in perhaps producing a few thunderstorms.
Regards,
Jimmy Deguara
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Hi guys,
Fingers crossed, we see something decent emerge from this system, even a small active squall line would be nice to see! Are there any clear indications as to what the trough might do in the way of storms as yet?
From the past few years records of chases we should be poised for the start of the storm season very soon! :)
My camera is dusted off and the batteries are charged so I'll be ready if anything wants to make itself known out our way!
Cheers guys and take care!
Shauno
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Have briefly checked the Sunday 00z runs of GFS and LAPS/MESOLAPS are they vary quite a bit in where activity is forecast for Monday/Tuesday. GFS is certainly less favourable for my area on Tuesday with the trough and moisture shooting out to sea by early arvo. If anything forms, it's certainly going to be moving along fairly rapidly.
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Shaun is on the money here with storms congealing into a squall line based on current analysis of the models. Time will tell I guess.
Regards,
Jimmy Deguara
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Yeah, I thought that too, I mean it's rather suspicious the models would be predicting all this "rain" I concluded that there should be high precipitation in the storms, ie some sort of squall line or a line of them, however with moisture being closer to the coast, means the darling downs and granite belt might miss out, however Anthony said on WZ that Sunshine Coast and north of there would be a "safer bet" whatever that means?
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Hi guys,
Not looking too good out this way (as yet), some nice photogenic virga thats been absolutely everywhere as of lunchtime! A few squally cells here and there and we do have one large cell to our North possibly around the Angledool / Hebel area but no sign of activity at the moment?
We'll keep an eye out as the afternoon progresses and be poised for anything that may come along though it is moving quite rapidly as Michael suggested!
Cheers guys and take care.
Shauno
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Hi Shauno,
Probably the same line of virga made it to Narrabri. No rain was recorded, but RADAR showed a fast-moving line >100km long which eventually broke up as it reached the mountains to our East.
On a different day it could have made a great squall line but the dew points were down around 0-5 degrees and so the cold front was lifting dry air and the cloud base was very high. As Shauno says the virga was prominent. There was even some curious mammatus looking cloud in the line which a few people remarked upon but I didn't have a camera to photograph.
Some more showers coming through now and there's still some lightning far out west.
Regards,
Dave
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Didn't get any photos, but the webcam images of the virga are kind of cute. Sorry these animated gifs are several MB each.. nobody seems to be able to view any mpg's that I build..
Narrabri Webcam West View (http://australiasevereweather.com/storm_news/2007/thumbs/narrabri_webcam_w.gif)
Narrabri Webcam Northeast View (http://australiasevereweather.com/storm_news/2007/thumbs/narrabri_webcam_ne.gif)
MB edit: - added permanent links.
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Had a look at the Moree radar, at around lunch time, to me those cells didn't look severe, but then Moree does underestimate echos, but it is a shame that it was only virga, you guys could have done with some rain, tomorrow however is a different story as the cold front (or storm front) comes closer, and to be really honest it looks promising.
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Steven,
It is looking much less promising from now on. The main axis of the trough seems to be off the coast by maximum heating. To me you will see some large thunderstorms and lots of lightning activity 100 km or more off the coast. If anything happens near Brisbane or noth, it should move offshore very quickly. There was only one scenario that looked good on one model but none since in my opinion.
Regards,
Jimmy Deguara
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Well I doubt it will be a fizzer although if these storms do clear the coast quickly, it better be nighttime, or else capturing lightning won't work, despite your opinion, I still have high hopes. Although judging by the charts, anywhere south of Coolangatta to north of about Gympie should see some action perhaps. Bureau is pretty adamant as they say 'late storm' in the forecast, which to me sounds pretty okay.
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Hi guys,
Well we had no real luck with the storms here last night as you all know by now. The lightning tracker looked promising at around 6:00pm with a small line of cells between us (Lightning Ridge) and Brewarrina that were headed our way quite fast, but they soon split-up and dissapated rapidly with a cold North Easterly infeed. We did see a few distant flashes to our South but nothing decent unfortunately? I think we had a total of 0.2mm of rain from a couple of heavy cloud bursts at 9:30pm-ish (not quite enough to settle the dust though).
There was even some curious mammatus looking cloud in the line which a few people remarked upon but I didn't have a camera to photograph.
Hi David,
We did notice the mammatus which was really impressive just before the virga seemed to collapse out of it, putting on a fairly good show across the afternoon from each of the passing upper-level cumulus masses. Russ has a few shots of it so I'll persuede him to post them here asap.
No too sure about today as yet? It's not looking favourable at the moment, no humidity and the temps are just a little too low? Now, If we received a forecast in the 30+ degree range we would've all been set with this system ;)
Lets hope it warms somewhat before the next trough approaches! :)
Cheers and take care.
Shauno
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Right on the coast Forster to Port Macquarie has fired in the past 30 minutes. Rather dry looking here atm as expected. dew point of 9 and gusty N-NW winds.
Image at 12.40pm
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Small cell near Grafton although as fast as it formed has now almost dissipated and quickly moved out to sea as Jimmy suggested would happen, but it now concerns me there has been no development so far, but lets keep playing the waiting game.
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Quite a decent cell off the Clarence Coast now.
Today has reminded me of 10th October 2003 (http://australiasevereweather.com/storm_news/2003/docs/200310-02.htm) where cells struggled for moisture but were visually quite impressive - but low topped - isolated cells.
Some congestus locally to my west that has a very moisture starved appearance.
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Well I'm going to write it off for now, it won't be until late until something might happen, but until then, its fine weather.
The obvious lack of moisture is the reason nothing is happening.
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Ok now, things are beginning to kick off, the Warrego radar is showing some development to the north east, however a bit early to tell yet considering things have just started, but its a sign of the storms approaching close along with the trough. Since the lack of moisture, we could end up with a storm like the 29 November, 2006 one, high topped, dry and very lightning active.
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Anyway, our chances are looking bleaker by the minute, nothing has happened and the upper trough has almost moved through, but I won't rule out any development out to sea though, might even see some lightning, but in general we might as well forget about it. How disappointing.
Update: In the last 20 minutes, Brisbane south suburbs are experiencing from small yet some intense thunderstorms, that are popping up very quickly, with large rain and small hail, no lightning sighted however, but with the trough closing in, we have to determine how fast these storms develop, IMO things are likely to stay this way.
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(http://sinkcat.data-zoid.com/virga_600.jpg)
http://sinkcat.data-zoid.com/virga_1200.jpg
Panorama from my roof. Not the best panorama ever, it was hand-held and I can't be bothered fixing it up properly.
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Coming home from school today in southern Sydney, I saw a few cells off the coast way to the north east. One looked quite impressive with a highly pronounced back sheared anvil. When I got home I looked at the newcastle radar and there was hardly anything.
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Mitch,
There was a cell that was reasonable but I think you will find high based. This means the top part is very impressive looking but precipitation cannot seem to last long enough. So your observations were pretty accurate.
All this talk about supercells on the other forum - I never did buy that. The wind profile even off the coast and mismatch of the trough axis made the storms even off the coast relatively disappointing.
Regards,
Jimmy Deguara
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Well now who has their heart broken, nah just kidding. This is the unfortunate price you pay for having high hopes about things. But anyway I'd now beleive you more than I ever did before, but since stuff on the "other" forum (which shall remain unnamed) theres quite a bit of wishful thinking going on.
Not having very advanced skill and knowledge of thunderstorms, their formation and such, it always pays to listen to someone who knows what they are talking about, otherwise you'll get "theres still a chance" business, which is really confusing, and frustrating in the end, ah well better luck next time.
:(
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The cells (showers in many cases) that passed over the greater Brisbane area during the evening were quite small and had very little lightning. I did not spot a single lightning flash despite a clear view in that direction from here. Lightning tracker showed none apart from one small brief storm east of Warwick.
There was quite a bit of lightning east of here from 10 to 11pm but it was not close to the coast.
The two storms that moved east off the coast from the Grafton area were the highlight from this system in this region.
---> Grafton radar loop (http://australiasevereweather.com/storm_news/2007/radar/20070911/grafton128.htm)
(http://australiasevereweather.com/storm_news/2007/satpics/2007091105.jpg) (http://australiasevereweather.com/storm_news/2007/satpics/2007091106.jpg)
MB
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Steven,
Without deviating from topic, if you are not willing to accept the inevitable and only wishful thinking, then that is what will come out of the forecast. I am not saying anyone was wrong just people hoping things will happen will eventually fall down the mindful thoughts of it happening. We need not comment any further on this.
Back on track, being so cold aloft I would not be surprised that perhaps pea sized hail occurred? Is this what you heard of?
Regards,
Jimmy Deguara
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Jimmy, Michael,
All I want is a good DECENT summer storm! I bet everybody does.
I am not pointing the blame at anybody, but yes there were a few willing to hold on, when there was no point, it was a terrible disappointment, and we were all wrong, not that theres anything wrong with that of course. But if you notice I am always cautious of these events, not trying to maintain such a high hope, always works the opposite, but last night I really did, but oh well.
Last night, a few small but intense cells developed in isolated places, a couple south of Brisbane, they were brief, short and sharp with their characteristics, both storms in Brisbane contained small hail and large drops of rain, but these dissipated in about 10 minutes, no lightning was observed in these storms. Although a storm last night around the hinterland did have some lightning, I didn't get a sighting.
With the extremely cold air above, quickly developing storms would have produced hail in no time, any that did fall melted quickly in the warm atmosphere.