Severe thunderstorms warning Canterbury 8/12/2013

[Richard]

Valid to: Midnight Sunday 8 Dec 2013

Issued at: 11:30am Saturday 7 Dec 2013

During Sunday afternoon and evening the low pressure system continues to move slowly across the South Island. The moderate to high risk of thunderstorm in the west from Westland to western Nelson is expected to diminish in the evening, but until then further heavy rain, hail and strong wind gusts can be expected with any thunderstorms.

In the east of the South Island, the risk of thunderstorms developing increases to moderate during the afternoon in Canterbury and Marlborough. Any thunderstorms that do develop have the potential to bring heavy rain of 10-25mm/hr and hail 10-20mm in diameter. Additionlly there is low risk that the thunderstorms could be SEVERE in Canterbury north of about Christchurch and southern parts of Marlborough, bringing the possibility of localised heavy rain greater than 25mm/hr and hail larger than 20mm in diameter.

A lower risk of thunderstorms extends to North Otago during the afternoon and evening.

Over the southwest of the North Island, in Taranaki, Kapiti Coast and Wellington,the low risk of thunderstorms continues into the afternoon.

Not often you see a severe thunderstorm warning for the Canterbury area.
Given that large hail is pretty much unheard of in my area i dont want tomorrow to be one of those days where hail of that size does end up eventuating and that bloody arrow is pointing at my place again too

[03Stormchaser]

Yeah looks good, I will be chasing, might be a few of us out there as I think most are free tomorrow

[Richard]

Yes ,very nice of the weather gods to time it for Sunday

[mikestormchaser]

Yes so a chase day does look likely then tomorrow.. dont know what i was looking at but i never saw tomorrow as anything super exciting but from what iv been told and read iv been proved wrong!! witch is a good thing lol
Anyways, should chase with 03stormchaser and jase tomorrow. hopefully aaron can get out aswel!

[tgsnoopy]

Severe Thunderstorm Outlook

Valid to: Noon Sunday 8 Dec 2013

Issued at: 9:04pm Saturday 7 Dec 2013

The low over the Tasman Sea is forecast to approach northern Westland and Buller Sunday morning, preceded by a broad band of rain with a few embedded thunderstorms spiralling onto the West Coast of the South Island. In particular,there is a moderate risk of further thunderstorms in Buller and Westland,bringing localised heavy rain, strong wind gusts and small hail, but these should ease in South Westland during the morning.

In the east of South Island, conditions become increasingly unstable in Canterbury as a southerly change moves north during the morning to reach Christchurch around the middle of the day. As this change converges with warmer air inland, there is a moderate risk of thunderstorms triggering over the Plains and foothills then spreading to Christchurch late morning. Any storms that eventuate have the potential to bring localised heavy rain and hail.

Outside these areas, there is a low risk of thunderstorms Sunday morning from South Canterbury across to northern Fiordland and up to northwest Nelson, also across the Outer Marlborough Sounds to Wellington and Kapiti, and for Taranaki.

Elsewhere, no thunderstorms expected.

Morn8Dec13.png

Valid to: Midnight Sunday 8 Dec 2013

Issued at: 9:19pm Saturday 7 Dec 2013

During Sunday afternoon and evening the low pressure system is forecast to cross the top of the South Island while a southerly change moves northwards through North Canterbury and Marlborough.

In the west of the South Island, there is a continued moderate risk of thunderstorms for North Westland and Buller during the afternoon, where localised heavy rain, strong wind gusts and small hail are possible. Any thunderstorms in these areas should ease by evening as the low and rainband move east.

In the east, the southerly change over the foothills and near Christchurch at midday is forecast to move northwards through North Canterbury in the afternoon and into Marlborough early evening. There is a moderate risk of thunderstorms accompanying this change and these could become intense for a time in North Canterbury and the far south of Marlborough in the afternoon resulting in a risk of SEVERE storms capable of producing large hail of diameter 20mm or more and downpours exceeding 25mm/hr.

Outside these areas there is a low risk of thunderstorms in the afternoon and evening from South Canterbury up to Marlborough, also for Nelson, Wellington,Kapiti and Taranaki, but this risk gradually diminishes from the south.

Elsewhere, no thunderstorms expected.

Aftn8Dec13.png

[tgsnoopy]

So last nights one saved, be interesting to see the updates.

Hope it pans out for you guys down there.

[Richard]

Yes,hope so too,missed out on the last few times they were forcasted.

Suns out the winds gone from the NW to more of a NE now so the circulation effect of the incoming low is happening.

[Manukau heads obs]

thunderstorm watch out now for Canty
have a good day guys/gals!

[Storm Struck]

I am trying to decide whether to hold fort here north of the bridge until things start firing, or head south then follow the action as it will be slow moving today.
But I am sure today should be a good set up will be watching out for the large hail, might even be some funnels to watch for .
Currently there is blue sky which is good and the wind is a light northerly on 20C.

[mikestormchaser]

TCU going up south from mine atm, keeping watch.. radar has some showers developing south of ashburton aswel.

[Orion]

All sorts of clouds - shreds, lines, towers - criss-crossing at different levels from various directions here: fascinating!

[dogmelon]

North Canterbury is the place to be for this. It just doesn't look or 'feel' like a chc thing today. Of course, I'd be pleased to be wrong. I'm very much an armchair in the backyard storm chaser, no driving for me.

[Powermad]

I'll be on the road..

[tgsnoopy]

Severe Thunderstorm Outlook

Valid to: Midnight Sunday 8 Dec 2013

Issued at: 9:13am Sunday 8 Dec 2013

A large low pressure system is forecast to cross the South Island today while a southerly change moves northwards through North Canterbury and Marlborough.

In the west of the South Island, there is a low risk of thunderstorms for North Westland this morning and early afternoon, and a moderate risk in Buller and western Nelson until evening. Thunderstorms in these areas could produce heavy rain of 10-25mm/hr and hail.

In the east, thunderstorms are expected to develop in Canterbury by early afternoon and Marlborough during the afternoon. There is a moderate risk of thunderstorms this afternoon and evening in Mid and North Canterbury and in Marlborough, producing localised heavy rain of 10-25mm/hr and hail 10-20mm in diameter. Additioanlly there is moderate risk of SEVERE THUNDERSTORMS this afternoon between Rakaia and Kaikoura, briniging localised downpours of 25-35mm/hr and hail larger than 20mm in diameter. A SEVERE THUNDERSTORMS WATCH has been issued.

Outside these areas, there is a low risk of thunderstorms in the afternoon and evening about North Otago and South Canterbury, the Marlborough Sounds, also for Nelson, most of Wellington and Taranaki. However in the north of Wellington and about the Kapiti Coast there is a moderate risk of thunderstorms this afternoon and evening.

Elsewhere, no thunderstorms expected.

Sun8Dec13.png

[Rogue]

I'm keen to chase today if anyone has a spare seat and doesn't mind accommodating a novice, will chip in for petrol etc.

[Bradley]

Lol, epic fail by metservice re: thunderstorms this morninh, not one in sight...

[Lawrence]

Looking a bit dark to the west of here

[Richard]

Lol, epic fail by metservice re: thunderstorms this morninh, not one in sight...

They are only just forming over South Canterbury now,too early to call that yet

[Storm Struck]

Gahhh im not liking this NWer I think its drawing further east than depicted the cloud tops show the weak shearing over at the tops, still its only just starting to get going so time will tell.

[tgsnoopy]

Watch Sun8Dec13.png

SEVERE THUNDERSTORM WATCH

Issued by MetService at 08:37 am Sunday 08 December 2013
Valid until 07:00 pm Sunday 08 December 2013
This watch affects people in the following weather forecast districts:
Marlborough
Christchurch
Canterbury Plains
Canterbury High Country

Thuderstorms are expected to develop in Canterbury and Marlborough this afternoon. In localised areas from the Rakaia River to Kaikoura some of these thunderstorms have the potential to be SEVERE, producing heavy rain with intensities of 25-35mm/hr and hail larger than 25mm in diameter.

Rainfall of this intensity can cause flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips. Driving conditions will also be hazardous with surface flooding and poor visibility in heavy rain.

Large hail can cause significant damage to crops, orchards, vines, glasshouses and vehicles, as well as make driving conditions hazardous.


Note: A Severe Thunderstorm Watch means conditions are favourable for severe thunderstorms in and close to the watch area. People in these areas should be on the lookout for threatening weather conditions and listen for possible Severe Thunderstorm Warnings.


Issued by: Gerard Barrow

This watch will be updated by: 02:00 pm Sunday 08 December 2013

[Lawrence]

Can't see any instability yet. Looking really dark to the SW. Check my web cam

[CHCH Weather Chaser]

Unstable signs around here in Halswell over past 2 hours or so but as you say its clouded over with high cloud above now and much cooler.

Radar shows development directly west of the city inland.

[Richard]

Still warm here with 22deg,all the unstable stuff to the south

[dogmelon]

It looks like something has gone boom on the radar out Hororata way. Maybe its not a bust yet.

[Powermad]

I don't think the NW will last.