Storm Australian Severe Weather Forum
Severe Weather Discussion => Australian Severe Storms, Weather Events and Storm Chasing => Topic started by: Jeff Brislane on 07 January 2006, 10:13:15 AM
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We'll my theory in the forcast thread for today is being sorely tested as a severe looking storm on radar approaches goulburn as I type. It looks like it's more than likely got hail in it's core and it could be anything up to 4cm's but not much over that as the conditions aren't favourable imo for larger hail. The storm is moving almost due north and it's anvil is streaming off to the east so it's not interfering with it's inflow at this stage. Batten down the hatches!
Jeff.
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Thanks for the warning!!! Check out the timestamp on this BoM severe thunderstorm warning.
Australian Government Bureau of Meteorology
New South Wales
TOP PRIORITY FOR IMMEDIATE BROADCAST
NSW SEVERE THUNDERSTORM WARNING
for LARGE HAILSTONES, DAMAGING WIND and VERY HEAVY RAINFALL
For people in parts of the
Illawarra,
Central Tablelands and
Southern Tablelands Forecast Districts.
Issued at 3:44 PM Friday, 6 January 2006.
Severe thunderstorms are likely to produce large hailstones, damaging winds and
very heavy rainfall in the warning area over the next several hours.
Major locations within the warning area include Bowral, Katoomba and Goulburn.
3:44 pm happens to be 5 minutes before a giant storm with probable hail in it's core slammed into Gouldburn. Who are they kidding with pathetic warnings like that? Is 5 minutes really an adequate warning?
I'm not a bom basher but how much of an idea do they really have with such little warning time? Or was the only person on the severe weather desk busy making coffee?
Jeff.
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Actually, according to the Sydney radar, Gouldburn was actually being smashed when the warning was issued so it makes you wonder if someone rang them with a hail or severe wind report and they reacted to that??? One can only speculate.
Jeff.
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Hi Jeff,
definitely it was a classic storm down east of Taralga and now twin intense cells near Muswellbrook (6:30pm). Paul Graham reported a south-east change pushing through at the time and was hearing anvil thunder near Bundanoon. Very intense cell for a few frames. Jimmy and Geoff observed the strcuture near Goulburn.
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I headed out with my brother at around 2pm to see what might eventuate around the Oberon/Lithgow region. We didnt see anything noteworthy until a couple of hours later when I noticed some strong looking storms way to the south of Oberon. I decided to head south towards Shooters Hill and we arrived there at around 5pm. A couple of storm cells formed to our west developing some pretty solid rainshafts and the occasional rumble of thunder. Meanwhile the storms to the south were moving closer and thunder from these became audible at around 5:15pm. Low cloud unfortunately was a big nuisance today and I was unable to get any real good photos of the storms. I decided to head back home at 5:30pm and stopped a couple of times on the way back to check out the storms that were heading towards me from the south. The storms finally caught up with me at the bottom of Mt Victoria, however there was only some brief heavy rain and strong winds. I could see a particularly strong looking rainshaft towards Hampton when I stopped at the lookout at the top of Mt Victoria. There was also a few lightning flashes and deep rumbles when I was there, but nothing outstanding. On the way back home through Katoomba and Wentworth Falls the mist was very thick in the wake of the storms which made for some challenging driving.
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Hi guys,
It may have been a 2 hour wait but it was worth it - very nice structured severe storm this afternoon near Goulbourn! And a nice dumping of hail as well in the Goulbourn and nearby vicinity - hail to 3cm based on the thumps (not measured though). Great afternoon's chasing. Matt, we could have met up as we headed to Oberon via Goulbourn only to find ourselves heading toward Bathurst. I got your message when in range but concentrated on the chasing. I did not know where and if you were chasing. Try specifying next time as you would have had fun with the Bathurst stuff. It produced strong winds and hail to about 2cm though mostly 1 to 1.5cm. It did not last as long as the other storm further south.
Goulbourn
(http://www.australiasevereweather.com/photography/photos/2006/0106jd02.jpg)
(http://www.australiasevereweather.com/photography/photos/2006/0106jd05.jpg)
(http://www.australiasevereweather.com/photography/photos/2006/0106jd06.jpg)
Bathurst
(http://www.australiasevereweather.com/photography/photos/2006/0106jd09.jpg)
(http://www.australiasevereweather.com/photography/photos/2006/0106jd12.jpg)
Regards,
Jimmy Deguara
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Hmmm, blue skies in Melbourne :( Looks like some great chasing up there. Nice photos as usual Jimmy. Very impressive structures. You can certainly see the power in the updraft of the Bathurst storm. Jimmy was there any hint of rotation on that lowering with the Goulburn storm? Im assuming it wasnt a supercell from the lack of description as such or do I assume wrong?
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Hi Brad,
I will check what timelapse I have to see if there was base organised rotation. Nevertheless, the storm was clean and did produce some damage! Trres down in the region NW of Goulbourn and the region on the way to Taralaga.
By the way, we headed to near Goulbourn to Taralga through to Oberon through to Bathurst, Sofala, east to Ilford, then Lithgow to Sydney. Saw 3 cop cars within 10 km on the way south of Marulan!
Regards,
Jimmy Deguara
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Hi Jimmy,
Those photos look great 8) I unfortunately couldnt have gone after the Bathurst storm as my brother was with me and he didnt have his medication with him which he needs to take every evening. We had a good time chasing though :)
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Here are a couple of photos which I took from Shooters Hill yesterday to give an idea of what I saw.
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That Goulburn storm had nice structure. Was it you that rang the BoM and triggered a severe thunderstorm warning Jimmy?
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Nope. I seldom call the BoM except when it is something serious:) I feel on a chase you have to concentrate on your own safety and any phone calls etc can be a distraction. You don't have time to stop and contact the BoM using the mobile. Besides everything adds up to the cost.
Regards,
Jimmy Deguara
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Jimmy - its Goulburn :)
Had a supercell up here on Friday. I was chasing with Rodney Wallbridge. Despite being in a perfect position it was difficult to observe, way too much low cloud - though what do you expect with the DP around 25 I guess !
These 2 pics at Mallanganee at 6pm, looking S and SE:
(http://australiasevereweather.com/temp/forum/photos/2006010601.jpg)
(http://australiasevereweather.com/temp/forum/photos/2006010602.jpg)
Rotation was evident in the clouds in the first pic - corresponds with this radar 0700z:
(http://australiasevereweather.com/temp/forum//200601060700.gif)
NE of previous location at 6.14pm looking ESE. Hail confirmed to cricket ball size was falling just beyond those hills.
(http://australiasevereweather.com/temp/forum/photos/2006010603.jpg)
And radar at 0710z with hook:
(http://australiasevereweather.com/temp/forum//200601060710.gif)
Later, we were treated to another storm at Casino. Winds hit 100km/h at the Casino AP AWS and the CGs were continuous ! Parts of the town were blacked out.
Got a bit of lightning later on too:
(http://australiasevereweather.com/temp/forum/photos/2006010604.jpg)
(http://australiasevereweather.com/temp/forum/photos/2006010605.jpg)
MB
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Hi Michael,
Thanks for the spelling - goodness I have always spelt it wrong - in my opinion it defies logic:) Melbourne vs Goulburn
Anyway enough of that, yes another 1 hour drive for you guys and cricket ball sized hail around the corner. Nice green tinge! And yes low bases. I would have liked to see the storm structure from a distance or was it low clouds the whole time?
Which part of the cloud base in the photo did you note rotation in? Was there inflow evident?
I'll post a pic from February last year to extend the discussion in regards to this storm.
Regards,
Jimmy Deguara
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We caught glimpses of the storm structure, but annoyingly mostly low cloud in the way. I estimate tops around 15ks or more - very high and strong verticle looking.
Clouds in left (closer) part of photo moving right, right (further back) part moving left around the back.
MB
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Hi Michael,
I take it the storm was evolving into a line - are you suggesting a bowing of r the storm and perhaps a book-end vortice? The "rotation" you suggest would be consistent as anticyclonic then.
Regards,
Jimmy Deguara
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Hi Jimmy,
Not a line with this storm but some other cells developed closely west of it. There was a line of activity later on. I do not recall inflow at our observation point on the Mallanaganee lookout.
Did you see the comments by Hararld Richter at the BoM about this storm:
5.30pm
"At 06z a likely supercell near Pretty Gully 115 km NNW of Grafton
sports 50 dBZ to 16 km, outbidding its southern neigbour who produced
50 dBZ to 14 km earlier (a form of one-upmanship among storms, I suppose).
The Pretty Gully storm has a mildly displaced echo on the N flank.
WDSS (an experimental radar-based algorithm) prints a hail size of 46 mm onto
my screen.
Apart from me being storm-starved, I think the sheer height of the 50 dBZ echoes
is impressive with this event. Very tall CAPE fed by deep rich
BL moisture seems to be the main driver of this event, but some
moderate deep layer shear has presumably created some updraught
rotation (judged by storm structure, longevity and anomalous motion)."
and at 6.15pm
"Impressive supercell over Malanganee bound for Casino (~40 min) at 7z. 50 dB echo tops remain
very high ( > 14 km) and are generously displaced to the N of the ll core.
A clear pendant echo has developed on the NW flank at low levels.
Hail sizes should be such that clubs can now be exchanged for bats ..."
MB
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HI Guys.
Very nice photos!
Michael how does this season rate in your own experience? - from down here it seems to be rather, should I say very active!
Jimmy, looks like Feb 16 2002 all over again from your pics. Was that wall cloud totally undercut or where you seeing rotation?
It did look very impressive on the stock standard PPI scans for a bit :)
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Hi David - extremely active ! There have now been 60 storm days in the Northern Rivers since 1st September. I've chased all the good days which is roughly 30 chases. So it is far better than any other season.
MB
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Hi Michael and David,
The information from Harald is interesting and it no doubt was a supercell - I was just wandering Michael in terms of the motion you suggested whether the storm was in a bowing out mode.
David the storm structure does look a little like the 16th February 2002. There was very strong southeast winds that fed under the wall cloud. This structure maintained up until at the least the point we were there. I have yet to check the video.
Regards,
Jimmy Deguara