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The Passage of an Upper Level Trough...

Posted: Mon 18/10/2004 18:39
by NZ Thunderstorm Soc
The passage of an upper level trough may induce thunderstorm activity over the South Island on Tuesday and the North Island on Wednesday.
Issued: 15 October


This was quoted by MetService....and they have maintained that in the Severe Weather Outlooks since then

Where are they likely to happen?
I have my batteries in my video camera charged just incase they move over Canterbury :) \:D/
Can't wait ;)

JohnGaul
NZTS

Posted: Mon 18/10/2004 19:26
by NZstorm
My thoughts on this upper trough is that the air coming with it will be fairly dry. For decent convection there will need to be some good surface heating with it. But thunder/hail a slight possibility over inland North Island Wednesday, mainly over the central high country.

Posted: Tue 19/10/2004 12:27
by C-Nimbus
NZTS or NZstorm,
could you please give me a link to where the metservice make these comments?

cheers

C

Posted: Tue 19/10/2004 13:00
by Manukau heads obs
http://www.metservice.co.nz/default/ind ... ss=warning

i.e the severe weather outlook or watch, etc

Re: The Passage of an Upper Level Trough...

Posted: Tue 19/10/2004 13:42
by 03Stormchaser
NZ Thunderstorm Soc wrote:The passage of an upper level trough may induce thunderstorm activity over the South Island on Tuesday and the North Island on Wednesday.
Issued: 15 October


This was quoted by MetService....and they have maintained that in the Severe Weather Outlooks since then

JohnGaul
NZTS

I see the have changed this now just to the north Island for wednesday, Still there are some small build ups now appearing above BP :)

Posted: Tue 19/10/2004 13:44
by Fujita Phil
03 Stormchaser wrote:I see the have changed this now just to the north Island for wednesday, Still there are some small build ups now appearing above the BP
Same here. A few build-ups to the West... camera in the car, ready to go

Posted: Tue 19/10/2004 13:47
by 03Stormchaser
Im Wrong!! :oops:

Metservice have forcasted for Canterbury and Otago
"Showers developing this afternoon with isolated thunderstorms,
Showers clearing overnight and becoming fine"


Who knows what we might have in CHCH with the current NE blowing!

Phil keep that camera ready!!

Posted: Tue 19/10/2004 15:44
by Thunder
'Yes indeed do!! I hope something happens here to 03Storm. And I retract my statement from the other thread, possiblity of FC's is ok!

Cu building on the plains.

Posted: Tue 19/10/2004 15:54
by Manukau heads obs
no lightning strikes record yet off the west coast with this next system.,....yet....hummm

Posted: Tue 19/10/2004 15:58
by NZ Thunderstorm Soc
I have a 3 warning up folks, see other tread :D

JohnGaul
NZTS

Posted: Tue 19/10/2004 17:22
by NZ Thunderstorm Soc
Picking up a few sfreicals, nothing much on Stephen's lightning detector tho', just a couple of strikes off Fjordland. Seem closer than that :-k

JohnGaul
NZTS

Posted: Tue 19/10/2004 17:30
by Fujita Phil
There's a great looking build-up WSW of here, but a bit hard to photograph. A long way away, looking in the direction of the big round sunny thing and some idiot put a big hill in the way.

Also another one a little more WNW of here that seems to be losing it's form minute by minute?

Oh well, I can only but observe and see what happens

Posted: Tue 19/10/2004 17:39
by spwill
Thunderstorms like the warmth, It's a shame you have had such a cool day down there.
Deano in Qld might see a storm this Evening looking at the current satellite.

Posted: Tue 19/10/2004 17:56
by tich
Still there are some small build ups now appearing above BP
No more than a bit of cumulus over BP. I did notice cb clouds over the Alps as I was coming back into Chch around 5PM today - a large 'thunderhead' looked as if it was over about the Tekapo area. Also some thin but unstable looking white high cloud inland. (I'm not sure what it's called)

Posted: Tue 19/10/2004 18:17
by Thunder
I can see altocumulus castellanus outside, something's about to happen methinks!!

Posted: Tue 19/10/2004 18:21
by Skywatcher
NZ Thunderstorm Soc wrote:Picking up a few sfreicals, nothing much on Stephen's lightning detector tho', just a couple of strikes off Fjordland. Seem closer than that :-k

JohnGaul
NZTS
It's overestimating the range of the strikes in that direction - Ricky mentioned a similar issue with storms in Waikato appearing Wairarapa. I've adjusted the ranging a bit but I'll leave more tinkering until later.

The direction has been corrected as well but appears to be wrong on the combined StormVue :?

The strikes are about 150km from here where Ben saw the thunderhead.

Posted: Tue 19/10/2004 18:34
by NZ Thunderstorm Soc
NZ Thunderstorm Soc wrote:Picking up a few sfreicals, nothing much on Stephen's lightning detector tho', just a couple of strikes off Fjordland. Seem closer than that :-k

JohnGaul
NZTS
.........immmmmmmmmmm thinking :-k

more strikes off the Fjordland/ south Westland coast, moving NE

...maybe what I'm picking up, is that plus mostly CC ?

This is an upper level trough development.
Imagine if this was combined with something on the surface???
I thought Cu development was rather weak around the Port Hills and when I checked to see that the barometer was about standard pressure so not really expecting anything to happen...but the sfrecals maintain my alertness at 3


JohnGaul
NZTS
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PS. how come on this forum there hasn't been any mention/reports from Hawkes Bay storm? :-k

Posted: Tue 19/10/2004 18:40
by Fujita Phil
Everything has slid North behind me... oh well

Posted: Tue 19/10/2004 18:48
by tich
PS. how come on this forum there hasn't been any mention/reports from Hawkes Bay storm?
You'd think there would be - there are a few Hawkes Bay (and near Napier I believe) members of this forum.

Posted: Tue 19/10/2004 19:03
by NZstorm
PS. how come on this forum there hasn't been any mention/reports from Hawkes Bay storm?
A reporter from the area on National Radio yesterday said it was a spectacular early morning thunderstorm with 51mm in 3hrs.

Just add that I think Gisborne region will get a thunderstorm off this trough tomorrow, much less likely elsewhere.

Posted: Tue 19/10/2004 19:50
by Skywatcher
Here's the 7:23pm NOAA12 satellite image showing the storm and a Cb to the NW of Dunedin. Pity about the loss of sync right in the middle !!!

I've now fixed the NZ StormVue antenna offset problem.

Posted: Tue 19/10/2004 20:29
by tich
No more than a bit of cumulus over BP. I did notice cb clouds over the Alps as I was coming back into Chch around 5PM today - a large 'thunderhead' looked as if it was over about the Tekapo area.
7PM radar still shows a bright patch over the Mackenzie Country.

Posted: Tue 19/10/2004 22:42
by 03Stormchaser
Well Aaron and I have 'again' picked up a bad case of Stormchasing! (Left at about 6pm and have just gotten back 10pm) We were off again today chasing what was a decent towering cb, We plotted it somewere over Ashbourton way, but must have been much further south.
We headed south to Dunsandal, then inland thru Hororata, and up to Mt Somers thru the Rakaia Gorge and finally back to CHCH via the main south road, all up about 250km all for a couple of spots of rain and a possible 'flash' of lightning!!

Yup we have got it bad!!

Posted: Tue 19/10/2004 22:51
by 03Stormchaser
http://www.metvuw.com/radar/radar-big.c ... 0Z_cny.gif

Here is the 7pm radar it was what we were headed too!!

Posted: Tue 19/10/2004 23:22
by NZ Thunderstorm Soc
03 Stormchaser wrote:Well Aaron and I have 'again' picked up a bad case of Stormchasing! (Left at about 6pm and have just gotten back 10pm) We were off again today chasing what was a decent towering cb, We plotted it somewere over Ashbourton way, but must have been much further south.
We headed south to Dunsandal, then inland thru Hororata, and up to Mt Somers thru the Rakaia Gorge and finally back to CHCH via the main south road, all up about 250km all for a couple of spots of rain and a possible 'flash' of lightning!!

Yup we have got it bad!!

sorry fellas , you had a bit of a bad day.
Even tho' you can can see castelatus clouds in the moonlight now.
NZTS Potential Alertnes No 3 now cancelled :(
Nothing much on the horizon :(


JohnGaul
NZTS