Thunderstorms somewhere in NZ on 24-25/08/05

Thunder · Unread post by **Thunder** » Tue 23/08/2005 20:07

Somewhere should get something tomorrow, I would imagine as you say NZStorm, Taranaki will get some storms and also Auckland etc look like getting something (here's hoping!).

Cantab also has a chance but it seems less. Here's the two skew-t's for tomorrow. Cantebury at 03z when the upper trough is overhead and the southerly change comes through (not very strong), hopefully it's enough to trigger something. And then the other at 09z (NZAA) when the upper trough moves onto Northland/ Auckland.

Cheers

NZstorm · Unread post by **NZstorm** » Tue 23/08/2005 20:40

The unstable cold pool out in the Tasman looks like it will track further north now, with most of the instability passing north of the North Island.

As for Canterbury, I think the upper air won't be quite cold enough. This type of situation in November can be more fruitful as surface temperatures and dewpoints would be higher and the NE would have more guts to it.

Willoughby · Unread post by **Willoughby** » Tue 23/08/2005 20:45

Sorry Aaron, I can't see anything for Christchurch, becomimg fine late morning with light NE in the morning, SW PM and then NE again by evening.

GFS is modelling LI down to -1.8 for both Auckland and Hamilton respectively, and CAPE looks kind of supportive. There seems to be a rapid drop in modelled cloud cover too tomorrow afternoon, which could induce further development, but this will couple with a cooler change.

It's also suggesting Northland/Auckland/Waikato/ has a higher risk than Taranaki

NZstorm · Unread post by **NZstorm** » Tue 23/08/2005 20:50

It's also suggesting Northland/Auckland/Waikato/ has a higher risk than Taranaki

Yes, I agree. The unstable weather looks further north now. As indicated in my last post, perhaps to far north.

Thunder · Unread post by **Thunder** » Tue 23/08/2005 21:18

Guess we'll have to see. The upper cold pool certainly seems to spread over Canterbury through to Auckland with LAPS (-26 at 500mb), it's also showing some ok vorticity. Tottot are at 50 (even small splodges of 55 over Cantab, I like that!). The LAPS model actually want's to go for 17 degree temps before that southerly comes through which is quite high! I think 16 at the most but we'll see. Dewpoints should be around 10 degrees (which is quite good), but averaged out a bit lower. GFS gives an ouput that looks a little bit not as good but it's ruffly the same. But I guess we'll get something or we won't, I'd like somewhere to get something so we can have a photo on here

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There's the cold pool (upper trough) encroaching over Cantab (03z tomorrow) and later it spreads over the North Island at 09z.

Cheers

03Stormchaser · Unread post by **03Stormchaser** » Tue 23/08/2005 21:38

Well Aaron and I have been poking a stick at the 24th for a while now and Im still not overly convinced, the upper air of around -25C I dont think its enough for this time of year, I think we need -30C, also i think that that dewpoint temp is a little too high, although I must give you some crediblity as Metservice also have a moderate warning out!!

Lets hope your right!!

Thunder · Unread post by **Thunder** » Tue 23/08/2005 21:43

Once again I don't say they will happen but there is a chance more so than other times. No it isn't a type of situation that I would say yes to storms tomorrow either, I'm not that confident. Mainly becuase of the time of year in general and the strength of that southerly.

Dewpoints have been 10 degrees today, I don't see that air being pushed out of the way until that southerly arrives so it should remain at around 10.

Cheers

Storm Struck · Unread post by **Storm Struck** » Tue 23/08/2005 21:56

Think back to Mid July or end of June I think it was wen we got that very slight thunderstorm come through at night now that was sorta out of season so wats so different about tomorrow i mean it's been rather mild latly.

Sounds like a long shot but I do have some good feelings on thunderstorms tomorrow afternoon but like everyone else I only have a tinkle feeling.

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Time will tell Iam sure we will get some hail or heavy showers out of it even if we don't get thunder chances are higher for that.
Tit for Tat really the weather is mad now days as the world is changing quickly

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Cheers
JASON.

spwill · Unread post by **spwill** » Tue 23/08/2005 22:10

Temps have been well above average in Canterbury for a little while now so the TS risk will be higher than normal for the time of year.

17 degree temps before that southerly comes through which is quite high! I think 16 at the most but we'll see. Dewpoints should be around 10 degrees (

Aaron,I think you have the dewpoints a bit high for 16, 17C .

Thunder · Unread post by **Thunder** » Tue 23/08/2005 22:34

Sorry, I mean 16 to 17 degree air temp with a 10 degree dewpoint, not 16 degree dewpoints. Agreed, that would be high! lol

Cheers

NZ Thunderstorm Soc · Tue 23/08/2005 23:14

I have given now a 1 for Canterbury considering all the options/scenarios/outcomes to which I have observed on this post.
This is incase something will happen.

With regards to the cold snap on Friday well anything could happen.

probably a fizzer like the last one

JohnGaul
NZTS

Manukau heads obs · Wed 24/08/2005 06:49

the low might move more towards northland/auckland?

very deep low now in the southern ocean, prognoisis maps have it at 942

Willoughby · Unread post by **Willoughby** » Wed 24/08/2005 08:20

Heavy rain earlier has eased to showers now. (20mm downtown since midnight)

Though New Plymouth and now Whangaparoa seem to be copping it within the last 3 hrs according to the 6am obs.

Keep watching that approaching trough in the Tasman!!!

Manukau heads obs · Wed 24/08/2005 08:27

only 8mm here....the best of the rain went just to the east of us here
13mmin waiuku, 18mm in pukekohe, 13mm in the big smoke

Storm Struck · Unread post by **Storm Struck** » Wed 24/08/2005 10:36

Yes some nice heavy stuff up your way I see Coromandel looks busy at 9am this morning on radar

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A circle of cloud over us at the moment blue all around the horizon unusual

should clear soon though even if no thunderstorms eventuate at least we should get heavy showers thats something to sqint your eyes at.
I see in paper this morning they say on Friday showers laced with hail and some sleet snow to 400m

I thought to get sleet the snow level had to be atleast past 200m because the way I see it everytime before its snowed here it rains then it sleets and the sleet turns to snow.
Cheers
JASON.

Storm Struck · Unread post by **Storm Struck** » Wed 24/08/2005 10:38

Yes some nice heavy stuff up your way I see Coromandel looks busy at 9am this morning on radar

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A circle of cloud over us at the moment blue all around the horizon unusual

should clear soon though even if no thunderstorms eventuate at least we should get heavy showers thats something to sqint your eyes at.
I see in paper this morning they say on Friday showers laced with hail and some sleet snow to 400m

I thought to get sleet the snow level had to be atleast past 200m because the way I see it everytime before its snowed here it rains then it sleets and the sleet turns to snow.
Cheers
JASON.

spwill · Unread post by **spwill** » Wed 24/08/2005 10:53

I thought to get sleet the snow level had to be atleast past 200m

The sleet/snow will be for higher locations than Chch.

Big Cu in our skies this morning, dew point 13C.

Storm Struck · Unread post by **Storm Struck** » Wed 24/08/2005 11:05

Since I last posted about half an hour ago SW has arrived precipitation can be visable falling in some areas and CB's to south now quite nice ones forming too lets just wait and see now

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Cheers
JASON.

Thunder · Unread post by **Thunder** » Wed 24/08/2005 11:45

Some heavy showers here now, Cb's to the south! Hopefully we get a thunderstorm!!

Cheers

Thunder · Unread post by **Thunder** » Wed 24/08/2005 13:07

Bugger, I think what ever was there is gone now. The day started off with some nice unstable forms (glaciated Cu, Accas etc) and then a Cb went up to the south off me but this Southerly has come through to early, if it had of just held off till this afternoon I feel we could well of been in for a thunderstorm.

Cheers

Storm Struck · Unread post by **Storm Struck** » Wed 24/08/2005 15:36

Yes bugger all here Atleast south canty got some heavy showers the only thing we got close to rain here was a few big drops of rain it was a different situation as the cloud was moving from the north to the south usually it's the other way around iam sure if it was the other way there would have been a thunderstorm for sure.
Ohh well Friday has a chance now with SW number 2 moving in be colder air too.

Cheers
JASON.

NZ Thunderstorm Soc · Wed 24/08/2005 16:12

Yes I saw some interesting forms during the morning and then whilst having a cup of tea outside about 11am, the trees gave a flutter from the SW and I thought "Oh no"

she's all over now"

...and that was it. Never saw or heard any rain/hail whatever. Lowerish status moved over later and all higher up interesting clouid dissapeared
Gone boring now
I wonder if Friday will live up to expectations or will that be yet another fizzer?????????

JohnGaul
NZTS

Willoughby · Unread post by **Willoughby** » Wed 24/08/2005 16:30

It really has been pouring today in Rotorua especially, about 50mm since midnight (25mm prior to 9am and 25mm after that(or near abouts)), 25mm here, almost 100mm today at the Kauaeranga catchment

Barometers still on the decline...

Trough inching closer, hopefully thunder tonight, but trackers not budging

NZstorm · Unread post by **NZstorm** » Wed 24/08/2005 17:21

Trough inching closer, hopefully thunder tonight, but trackers not budging

Trough out in Tasman won't make landfall before Dargaville. It is doing what the last one did, go straight over the top of us. As it moves north, should become more active over warmer seas.

Some cold unstable air looks to be on the way for lower South Island Friday.

Gary Roberts · Unread post by **Gary Roberts** » Wed 24/08/2005 17:31

NZstorm wrote:
Trough inching closer, hopefully thunder tonight, but trackers not budging
Trough out in Tasman won't make landfall before Dargaville. It is doing what the last one did, go straight over the top of us. As it moves north, should become more active over warmer seas.

Some cold unstable air looks to be on the way for lower South Island Friday.

It's been cloudy and drizzly all day in the Mackenzie, with a very light dusting of snow on the divide, but now nice and fine.