Thunderstorms possible North Island 8 October

[David]

Only just saw the thunderstorm outlook for tomorrow, and it sure looks nice!

ThunderstormOutlook081013.png

http://www.metservice.com/warnings/seve ... rm-outlook

Valid to: Midnight Tuesday 8 Oct 2013
Issued at: 11:12am Monday 7 Oct 2013

A low over the Tasman Sea is expected to approach New Zealand during Tuesday. A front associated with the low is forecast to move across the North Island in the afternoon and evening. This front is expected to bring a period of active thunderstorms to northern New Zealand, moving across northern Northland during the afternoon, southern Northland, Auckland, Coromandel Peninsula, Waikato, Waitomo, Taranaki in the afternoon and evening, and then move into the Bay of Plenty, Taupo and the central North Island in the evening.

For Northland, Auckland and Coromandel Peninsula, the risk of thunderstorms occuring is high, while Bay of Plenty, Waikato, Waitomo, Taumarunui and Taranaki the risk is moderate. These thunderstorms have the potential to produce heavy localised rain of 10-25mm/hr, strong winds gusting 90-110 km/h and possible small tornadoes. Additionally, for Northland, Auckland, Coromandel Peninsula and Bay of Plenty there is a low risk the thunderstorms could become SEVERE, producing down bursts with damaging winds gusting greater than 110 km/h and small tornadoes. For Taupo and Tongariro National Park the risk of thunderstorms in the evening is considered low. While for the Ruahine and Tararua ranges there is also a low risk of thunderstorms in the afternoon and evening.

Over the South Island, there is a moderate risk of thunderstorms during the afternoon and evening about northwest Nelson which could produce heavy rain and squally wind gusts, and a low risk in the evening in the remainder of Nelson and about the Marlborough Sounds.

No thunderstorms or significant convection expected over southern New Zealand.

[Manukau heads obs]

yes, just catching up on this now..wow...

[NZ Thunderstorm Soc]

Good luck to you guys up there whilst we enjoy the heavy convectional rain/snow here in Canterbury

[Tornado Tim]

Updated outlook this evening:

Issued at: 8:32pm Monday 7 Oct 2013

A deep low over the Tasman Sea is expected to approach New Zealand during Tuesday. An associated front is forecast to move across the North Island during the afternoon and evening. There is a moderate to high risk of thunderstorms for western areas from Northland and Auckland to Taranaki during the afternoon and early evening, then spreading into Coromandel Peninsula and Bay of Plenty in the evening. These thunderstorms may produce localised heavy rain and strong wind gusts of 90 to 110 km/h. In addition, there is a low risk of SEVERE THUNDERSTORMS with this front from Northland across to Bay of Plenty, with the possibility of damaging wind gusts in excess of 110 km/h, and a few small coastal tornadoes.

There is a low risk of thunderstorms for the inland Wairarapa and the Tararua and Ruahine ranges during the afternoon and early evening. For Taupo and Tongariro National Park the risk of thunderstorms in the evening is considered low.


Over the South Island, there is a low risk of a few thunderstorms as the front moves onto northwest Nelson and the Marlborough Sounds.

No thunderstorms or significant convection expected over the remainder of New Zealand.

The WXSIM forecast for here is picking a mod to high risk of Storms tomorrow and then a moderate risk on Wednesday due to the left over moisture brought in by the low pressure trough.

[tgsnoopy]

Hmm, time to charge those batteries again I guess... Or maybe not. There should still be lots of charge from last week and I wouldn't want to Jinx anything. Decisions decisions

[NZstorm]

The front looks to cross Auckland mid afternoon so timed for heating. We should get 20C today which would be good for a thunderstorm. The front will pass through fairly quickly and be in the BOP by early evening.

[Manukau heads obs]

is this chase material?
all going to be messy with too much cloud (lots of high cloud here already)
anyone chasing?
I could meet at bombay...
looks to be a bit of a clearing in the sky after this messy warm front goes through

[spwill]

anyone chasing?
I could meet at bombay...

I'm going to watch the weather from here and see what can develop, could possibly meet at Bombay later.
Need the day to warm up now.

[jamie]

yea quiet day at work for me so I will watch and asses as the day progresses.

[jamie]

Sever thunderstorm watch is in force. It doesnt make it down to Hamilton.

I would have thought you guys in Auckland would want to head north west? Bit different for you Brian.

Hopefully something develops that is chaseable. I get the feeling though we wont be able to see all that much.

[spwill]

I would have thought you guys in Auckland would want to head north west? Bit different for you Brian.
.

See what can develop today.

For storm chasing the chase country/roading is much better over South Auckland/Waikato and you have the option to go east with a system into Coromadel/BOP.

[jamie]

For storm chasing the chase country/roading is much better over South Auckland/Waikato and you have the option to go east with a system into Coromadel/BOP.

That is true. Fair point. Very sunny and warm here. Had some light fog early thismorning too which is always a good sign of plenty of moisture.

[Manukau heads obs]

SPWill, can you PM me your cell number?
(as it did not get transfered to my new phone I have now)
ta

[Brassnz]

I'm driving down to Rotorua shortly. Fingers crossed for a great sound 'n' light show tonight in the Poly Pools!

[David]

Updated map for today attached. Basically the same as yesterday evening but the "Severe" risk has been upgraded to moderate.

[Tornado Tim]

Not entirely sure this event will be a "chase-able" one. There is a line of storms but it seems quite embedded at this stage looking at NZAPStrike(Blitzortung) and the IR sat Images.
PS: if you want to know how to capture the NZAPStrike Map's just use your browser OS Screenshot tool (Printscreen and or use snipit in Windows 7).

[jamie]

What are the chances of things developing ahead of the front? Some tcu out there at the moment.

[Manukau heads obs]

starting to get patches of blue sky here
and warming up steadily too

cell west of me is lightning active at the moment

my cell is 027 2359040

[Tornado Tim]

What are the chances of things developing ahead of the front? Some tcu out there at the moment.

I think that is/was associated with the Warm front. Slim chance I think (the Warm front carries lots of cloud that can inhibit DTSH)

[jamie]

Was that the warm front that passed over a while ago. More like at 9.30?

[spwill]

Current weather,18C with a dewpoint of 15C, cloud/ sunny spells. Not much on the front to the west currently, see what can develop over a warmed land.

[spwill]

Some thunderstorm activity over Northland hill country west of the Bay of Islands

[jamie]

Im not liking the looks of this front.

[seej]

Where is the actual front??...It's not even showing properly on the radar!...either it's very very weak, or its not even showing yet and is going to rip over the radar and towards us later on...

[spwill]

Yes, very little on the frontal line now which is still west of here, currently 19C dewpoint 15C, cloud/sunshine mix.
Some weak Cb observed to the southwest. Might get something east of here but yes not looking great.