Topic: QLD & NSW Severe Storms w/ Supercells, Large Hail, Lightning: 12-19 Dec 2010

[Colin Maitland]

Over the last few days the GFS runs keep throwing up the scenario of heavy rainfall totals over the next 48 hours for SEQ and the East Coast of Qld. BoM's Access seems to point to the same. 

Meanwhile further South including Victoria and South Australia, Anthony Duke reported on WZ News in an article titled                  
 "December snow for the Alps"

Cold air from the south in an upper level trough and widespread cloud cover has caused temperatures across the southeast to plummet. On Saturday, day time temperatures across Victoria, South Australia and parts of NSW were around 5 and 17 degrees below average. In South Australia Moomba Airport just reached 19 degrees, 17 below average. This is 3 degrees colder than their December minimum average. Elsewhere the places were in the Victorian Alps where temperatures were as cold as those seen in October. Mount Buller only managed to reach 2 degrees, 13 below average. Falls Creek warmed to just 3 degrees, the coldest it has been in December for 19 years. Wind gusts on the Alps around 50 to 70 km/h made temperatures feel more like minus 7! Temperatures are forecast to stay down over the next 48 hours in the southeast, bringing the potential for snow flurries on higher ground. Overnight on Sunday, temperatures are predicted to step below zero with Mount Hothom set to drop to minus 2. With temperatures this low, precipitation is likely to fall as snow to as low as 1200m. Temperatures are set to return to around average by mid-week in time for Christmas.

Col
 

[enak_12]

Check out these damage photos from just west of Coffs. The micro burst I shot the other night hit them hard out there!

http://www.coffscoastadvocate.com.au/photos/galleries/storms-sweep-through-region-coffs/#num=1&id=storms-sweep-through-region-coffs

Anyone think it was a right moving supercell? it certainly deviated right pretty sharply compared to the main flow of the other storms around. It was quite long lived as well, started from Guyra and made it out to sea. Heres the radar watch for the storm that goes through Coffs about 12:30 to 1:00pm.

See : 128km Radar Loop for Grafton, 23:00 15/12/2010 to 23:00 17/12/2010 UTC

[Jeff Brislane]

Won't say much about the Supercell that hit Penrith last Thursday except that it's radar signiture was awesome! Most powerfull storm i've seen in western Sydney for quite some time. Not as big hail as Blacktown supercell but more powerfull overall from my perspective.

Awesome Destructive Hailstorm - Penrith 16/12/2010.mpg

Regards Jeff.

[Richary]

More likely to be a mesovortice/mesocyclonic return or perhaps a particularly strong microburst within the storm itself. Generally with 128km radar doppler and given the scan height at that range you are unlikely to see a tornadic signature (just due to sheer scale, thing about how many pixels on that map represent a km), and the are usually more tight and confined on our radars when they do produce them.

Thanks, I did consider that ground level would be out of range of the Terrey Hills radar given the terrain in between. But it's just something I have never noticed before when looking at windfinding tracks of severe storms. Coupled with the bow (or was it a hook) echo that occurred at the same time in the rainfall I thought it interesting.

Whatever it was I am probably glad I wasn't under it!

Sorry for the delayed replies as well, I am in Perth on a work job now so forum checking and so on is taking a back seat for a few days.

[scottme]

I remember seeing what looked to be a hook on the doppler wind radar at the northwest corner of the Warragamba supercell just before it merged with the other cell travelling due east down the mountains.

Currently a STW for southern highlands, although things look like they're just getting started.

[David C]

Won't say much about the Supercell that hit Penrith last Thursday except that it's radar signiture was awesome! Most powerfull storm i've seen in western Sydney for quite some time. Not as big hail as Blacktown supercell but more powerfull overall from my perspective.

Awesome Destructive Hailstorm - Penrith 16/12/2010.mpg

Regards Jeff.

Nice footage of the hail,and welcome back Jeff!

Agree in terms of the intensity of this storm it was a good one. Looking back I am actually a bit annoyed that I was held up doing something at work, which had me out the door 30 minutes later than planned, as that made all the difference. ie would have been much closer to the cell as it approached Warragamba, whereas matching up my footage with radar, shows that I got the collapse phase of that meso (I could see it going from a tight barrel around 1:20 to 1:30 to what you see in my second last still and was out of position for the Penrith redevelopment).

by: pingtang
Fantastic supercell structure.  Lovely work from the rest of you guys as well! I dont care what anybody says, it was outbreak of the season as far as im concerned and not just NSW.

LOL Michael. There have been some I would go so far as to say 'uncharacteristic' severe storms out of Vic and SA this year, as you have chased, although consider it is generally a looooong  (VIC) to very Loooooooooooooong (SA) time between drinks for the guys down there, but things do evenetually happen when moisture actually gets in.  But agreed, this event is another several steps up the ladder.

Where is lightning chaser?  get him on here

[Antonio (stormboy)]

Does anyone know what is causing the sudden huge gusts of wind in NE nsw my station is going to register 60kms soon

Antonio.

[Paul D]

Finally managed to assemble a bit of lightning footage sequence and some timelapse from the 17th of December
Taken as a storm which had been moving NE from the Esk area began to merge with the rest of the east moving system over Kilcoy.
App 50+ strike events (incl many having multiple hits)from 18min of footage.
The shortest individual strike isn't actually visible unless you slow it down, just one single frame of branched CG followed before & after by zip..
Tacked in is a some footage as a guster moved over Maleny .

Dec 17 2010 Lightning show timelapse

Also a short timelapse from lightning still images of a guster the same night

sheet lightning guster timelapse 17 Dec 2010

Cheers
PaulD