Thunderstorm Risk - 11th,12th October - North and South

[NZstorm]

I may chase that trough this afternoon as dewpoints will be 10C and there will be some speed shear. There is the outside chance of a storm getting a bit active.

[jamie]

Yea but how will u keep up with it? They are moving so fast. I'm just going to stay put today and watch them go by.

[Manukau heads obs]

that NWer yesterday was interesting in that inland got strong winds...
often its only strong on the west coast....but thats usually associated with a pressure wind....i.e up against relatively stable airmass hugging the land, associated with a ridge of high pressure...but this time there was no ridge and there was more shallow instability rather than just upper level instability?

[Nev]

Pretty much the entire country has some risk in this morn's T-Storm update...

MetService - Severe Thunderstorm Outlook

Valid to: Midnight Saturday 12 Oct 2013
Issued at: 8:42am Saturday 12 Oct 2013

A very unstable southwesterly flow is expected to affect the country, easing this evening as a ridge approaches from the west. A trough embedded in the strong southwesterlies is expected to move east across the country this afternoon and evening.

From the south of Northland through Auckland and the west of Coromandel to Taranaki and Taumarunui there is a moderate risk of thunderstorms this afternoon with heavy rain, strong wind gusts,90 to 110 km/h and hail. There is also a low risk of damaging wind gusts.

From Wanganui south through Manawatu to Kapiti there is a moderate risk of thunderstorms this afternoon with heavy rain, strong wind gusts 90 to 100 km/h and hail.

In Buller and Westland there is a moderate risk of thunderstorms this afternoon with strong wind gusts, 90 km/h and hail.

From north Otago through Canterbury there is a moderate risk of thunderstorms this afternoon with hail.

In the south of Wairarapa and north along the Wairarapa coast there is a moderate risk of thunderstorms this afternoon and evening with strong wind gusts and small hail.

There is a low risk of thunderstorms for the remainder of New Zealand apart from the south of Fiordland as indicated on the map.

MetService T-Storm Map - Is Oct 12, 8.42am.png

[jamie]

got a thunderstorm about to roll in here. Hearing rumbles

[Manukau heads obs]

ohh, yup,that looks like a good one

[jamie]

looks good that there is a bit of clearance from now until this afternoon when that trough arrives

[Storm Struck]

Great set up today I feel in my books warrants our first high risk for the season, all ingrediants are there onshore fresh winds heating with clear crisp sky this morning and the jet stream plus upper air is -30C excellent .
Well worth the chase and I agree decent size hail with initial slow moving storms this afternoon maybe 15-20mm, not small hail like MS are saying.

Last night a weak storm snuck up on the front with purple/red on the radars quite sharply around midnight to 1am, some brief strikes were picked up near Ashburton.

Edit: Update now from MS had to have a wee snigger quoted from the thunder outlook..
From north Otago through Canterbury there is a moderate risk of thunderstorms this afternoon with medium sized hail.

Medium sized hail want fries with that??

[NZ Thunderstorm Soc]

Yes, Jason, I too had a wee sniggle at that.
Sounded like a forecast been dished out from a fish and chip shop
Hope the hail is not that big as I don't want more damage to the spring growth, trees, flowers etc.

[Richard]

you can have the medium sized hail down your way Jason,i'll just settle for some small thanks.

Must say the clouds are building nicely ATM,the SW wind had died so looking promising i reckon.

[mikestormchaser]

Looking good for a chase this afternoon with stormstruck and will meet up with 03stormchaser later aswel, beautiful day atm, clear skies, a little bit of CU around, hardly any wind, perfect ahead of the trough coming up this arvo!

[Tornado Tim]

A nice 70k squall came through just a few min ago, nice
However the temperature here is far too cold for that trough to ignite over land, we just keep on getting cold outflow and not much sun.......

Hopefully it will change, but I am not sure......

[03Stormchaser]

In mid canterbury. Couple nice bases toward the alps.no lightning yet

[03Stormchaser]

Looking toward Mt Somers

[Orion]

Acting on information received [thankyou], I've put the car under cover for the first time in years.
It's getting very dark here.
16.3 degrees.

[Nev]

I see MS this arvo have upgraded the risk of 'SEVERE thunderstorms' for the south of Northland to Taranaki area from low to moderate. General increase in hail size potential too.

[jamie]

ssome nasty looking stuff on our door step at the moment.

[Orion]

Thunder here now. Posting from phone for the future!

[snowstormwatcher]

Thunder and lightning here now, looks pretty dark over the hills.

[Orion]

Light rain, repeated peals of thunder.

[jamie]

Looks good inland from Timaru

[snowstormwatcher]

Heavy rain and hail here now along with a near gale Southerly.

[Orion]

Ten seconds between lightning and thunder. Seems to be to my NW or NNW now.

[snowstormwatcher]

Moved though here now. best Thunderstorm Ive seen in awhile though, Almost constant overhead lightning and thunder with 9mm of rain in 10mins.

[Tornado Tim]

Looks like you guys down south have 2 or 3 cells to go after, have fun