Topic: NSW / QLD Supercells: 10-11 Dec 2008

[Antonio (stormboy)]

Last night some thunderstorms hit ballina with a spectacular lightning show and later on about 11:15 winds hit us at around 70+kmph

Here are some lightning shots

[Michael Thomas]

First off, great photos there, awesome supercell structure! I must admit I was a little surprised by the severity of those two storms (not after seeing the radar images though). I was watching the radar most of the day and certainly earlier on all the storms were firing behind the change moving up the coast. Going by the model soundings I was under the impression that moisture depth was not so good ahead of the change. Obviously though, this was not the case. Replotting the model soundings with the surface obs from yesterday give CAPE generally around 2000 and up to almost 3000 j/kg (when plotted for 34/20). 500 hPa winds were WSW at around 30 knots and with N to NE winds at the surface 0-6km shear would have been around 40knot. On top of this, upper level winds were very strong (up to 100 knots at 200 hPa). With both supercells moving N, I would guess that this allowed them to move along the sea breeze front (or at least move along an area of locally higher CAPE away from the cooler surface temps by the coast).

Today certainly looks interesting too, lower level moisture has increased in SE Qld with dew points up to 22 C. The Brisbane sounding looks quite nice, I would say there should be sufficient shear and CAPE for supercells again today, especially on or just ahead of the SE change. It will be hard to match yesterday though.

Michael

[Jimmy Deguara]

Great supercells there guys. The development of structure on radar was awesome to see and it seems on the photographs show that. Some nice overshoots observed on both cells. Being slightly higher based, the mesocyclones could clear be seen wrapping around and from what I could see on Michael's pictures, there were inflow bands and a beaver tail by the looks of it. I also note an inflow notch cut in.

Any other comments?

Regards,

Jimmy Deguara

[Antonio (stormboy)]

today looks like a good day the radar already shows some storm cells developing near the casino and tenterfield area there are also some heading towards kyogle

heres the 3:30pm radar

[Michael Thomas]

Currently 33.5/22 at Beaudesert AWS, this gives a surface based CAPE of approx. 3000 j/kg when replotting the Brisbane sounding. Current cell NW of Kyogle is looking like a HP supercell with a nice 'kidney bean' shape and some rotation showing up on the doppler. Looks like SE Qld is primed for some decent severe storms this afternoon.

Michael

[Jeff Brislane]

That storm you mentioned Michael has a really nice signature on radar with sustained area of maximum reflectivity, and what appears to be slight left of flow movement, and it's even in Qld/N.S.W. so it must be a supercell. 

[Jeff Brislane]

Michael & James, Those storms are fantastic! Excellent structured supercells and Michael that shot with the hail shaft near the bus shelter is amazing seeing such a well defined distinction between inflow and outflow.

Kane, is that first photo of yours looking west at Coff's? And what time did you take that one? It shows some very nice and interesting storm structure.

[Antonio (stormboy)]

this is a video of the thunderstorms that hit us lats night at around 11pm

http://au.youtube.com/watch?v=wkLD0igBP6g

[Michael Thomas]

That storm certainly looked nicer earlier on, still a storm to keep an eye on though that's for sure. Latest obs show that the sea breeze front has pushed inland with winds shifting to the NE/E and a small increase in dew point temperatures. Still looking very nice for SE Qld, wish I was there. Just need these storms to get organised now.

[Jimmy Deguara]

Hi Michael,

Would probably call this a region of convergence - not so much a sea breeze front today as it is associated with the stalled SE change. I think this is confirmed by James Harris who was situated to the NW of Kyogle and was out of this stratocumulus crap.

Regards,

Jimmy Deguara

[Michael Thomas]

Hi Jimmy,

Ok, my mistake. There was a wind shift (to NE) and an jump in dew point temperature which I normally associate with the seabreeze moving in. Might not be the case today. I wondering if that storm is going to get organised soon, it certainly has lost any supercellular features. That doesn't mean it still can't pack a punch though.

[Richary]

Some great photos there, love those Grafton shots James.

Today got away from Narrabri early, and made Armidale a bit before 2pm. There was some development taking place west of Armidale but nothing was managing to push through the cap and they would just fall apart. As a total contrast about 50km east of Armidale started to run into low cloud (fog) and the run into Dorrigo was a slow one with very poor visibility. Aprox 100m a lot of the way and down to 50m at times. A total change in climate from the hot temps west and even at Armidale. So cloud base well down below 1000m as the fog hung in a fair way down the hill.

The storms to the NE of Armidale looked to be getting a little more structure early but didn't see if anything developed out of those.

[enak_12]

Hi Jeff yes that photo is looking back towards coffs it was taken at about the time of this radar image..



another pic at around the same time it was throwing out intense cg's .. looks like a beaver tail maybe on the right of the image?

 

[James]

I will post something a little more substantial later on. I based myself at Kyogle ready to make the jump across the border if need be. As Jimmy mentioned Kyogle and northwards was sitting very nicely near a convergance zone of the SE'er. Watched a few crappy cells go up but then noticed the low level cu starting to thicken up towards a base I could not see behind Kyogle (west). Moved north and watched a few little bases in front try to organise however the anvil rain from the big storm behind (near Woodenbong) was ruining the fun. I realised my best bet was to try and get to the back end storm (some seriously deep booming thunder from it) so headed on the Lions Road over to Rathdowney and then westwards to near Marom trying to get the main updraft on the north west flank near Woodenbong. Bases were forming on the northern edge of the outflow near Rathdowney however to the SW hidden bhind a rain curtain was the real thing. Arrving just east of Marom I was greeted with this to my south .... lots of pics and video however will put them up later as am out of time.

Lovely HP looking updraft with rotation.

   

[Mike]

An explosive looking storm.  I have been watching the radar loops for most of the east coast during these times and the size of the storms were impressive to say the least.