Topic: NSW Severe Storms 6 Jan 2006

[Jimmy Deguara]

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

[Michael Bath]

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

[David C]

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
 

[Michael Bath]

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

[Jimmy Deguara]

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