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Posted: Mon 19/12/2005 13:06
by Willoughby
Quite a rare event for the south.. great photos lyn and phil!

Don't think there will be many more storms for Dec down there.. too much high cloud today and then an impendiing S/SW flow

Posted: Mon 19/12/2005 13:18
by Flutterbye
Looking forward to the s/sw personally.

This is another shot of the same cloud that Phil snapped only mine isn't as good.

Posted: Mon 19/12/2005 13:18
by spwill
They do get quite a lot of severe thunderstorms down in the deep south.
Saw plenty when I lived down there, much better than any thing I've ever seen in Auckland. However most good storms down there are confined to the month of December in the afternoon to early Evening.



Thanks for the photo's.
Lyn, your last one looks interesting.

Posted: Mon 19/12/2005 13:22
by Fujita Phil
Flutterbye wrote:Looking forward to the s/sw personally.

This is another shot of the same cloud that Phil snapped only mine isn't as good.
Photos just didn't do it justice, eh Flutterbye?

Posted: Mon 19/12/2005 13:33
by C-Nimbus
i personally think this cell was an outflow dominant storm at the time the photo was taken as there is almost a 'gust fronty' appearance to it.

I also believe it may be meso-cyclonic (but on a small scale). My understanding of this is limited but the appearnce is similar to some of those big US supercell style storms. Maybe there is rotation in there and thats whats giving it this appearance.

persistent yukky rain in newmarket now. Rain radar has a blob of 'meh' type rain over us but no thunder and lightning yet. Experienced an awesome humilis to cumulonimbus Sequence in hamilton yesterday. Big classic waikato boilups with lovely crisp Cu and then 'bang' its all over ;)

hopefully some good action heading our way later

Posted: Mon 19/12/2005 13:56
by Flutterbye
I agree Phil - they sky was like nothing that I can recall seeing down here before and it was the length of the storm that surprised me.

Cheers
Lyn

Posted: Mon 19/12/2005 16:23
by NZstorm
I also believe it may be meso-cyclonic (but on a small scale). My understanding of this is limited but the appearnce is similar to some of those big US supercell style storms. Maybe there is rotation in there and thats whats giving it this appearance.
It does resemble a mesocyclone. :)

That was my first theory but the upper wind profile suggests otherwise.

Posted: Mon 19/12/2005 18:21
by NZstorm
Another problem with the meso theory is there was no rotation reported.

The cloud formation in Phils' photo will have been caused by differing airmasses, one riding over the other. There was hot drier air running into cooler, more moist outflow from the storm. Also there was a cooler southerly (sea breeze in the area). I would say the land breeze is riding over the outflow here giving the orographic look to the cloud in Phils photo.

Posted: Mon 19/12/2005 20:16
by C-Nimbus
NZstorm wrote:Another problem with the meso theory is there was no rotation reported.

The cloud formation in Phils' photo will have been caused by differing airmasses, one riding over the other. There was hot drier air running into cooler, more moist outflow from the storm. Also there was a cooler southerly (sea breeze in the area). I would say the land breeze is riding over the outflow here giving the orographic look to the cloud in Phils photo.
I geuss that would support the lenticular shape of the cloud, kinda similar to the mechanism of Alto Cu Lentic. forms. I wonder then what sort of air speeds would have been causing such clean edges. Is it similar in principle then to a Roll cloud?

No "High risk" T/S as yet this evening (as suggested by metserv) :roll: , but some pre-frontal looking clouds have rolled on in, and there were some quite cool looking spent anvils (i assume) out to the east of where i live.

Rickys tracker has picked up a line of the west coast of the NI but seems pretty lax at the mo....

Posted: Mon 19/12/2005 20:34
by Willoughby
C-Nimbus wrote: No "High risk" T/S as yet this evening (as suggested by metserv) :roll: , but some pre-frontal looking clouds have rolled on in, and there were some quite cool looking spent anvils (i assume) out to the east of where i live.

Rickys tracker has picked up a line of the west coast of the NI but seems pretty lax at the mo....
Rain continues to fall in the great basin.. yes there looks to be some recent thunderstorm cell development within the last half hour.. So dunno about Auckland.. RR has them tracking towards the Waikato.. so some storms look likely sometime tonight! :D

Further thunderstorms tomorrow morning under that cooler air

Cheers

Posted: Mon 19/12/2005 20:37
by Michael
We have a NW with lots of fast moving low cloud now 17c

Posted: Mon 19/12/2005 21:17
by NZstorm
Fine stable looking evening in Auckland with 9pm temp 20C, dp17C.
May see an isolated cb overnight. Next round of showers looks Tuesday afternoon.

Posted: Mon 19/12/2005 22:38
by Storm Struck
It's a lovly night out there tonight :D Smells like the West Coast wiht that damp moist smell light rain falling and 16C at 10:30pm.
Rain should continue overnight and until about midday tomorrow then it should fine up with a high of 27C expected. Those NW winds may reach severe gale inland but probly just gale force gusts in the afternoon here.
Nice to see a different pattern in the weather for a change finally after weeks of drearyness and drizzle.
Cheers
Jason.