Thunderstorms 18th December

[NZstorm]

With an unstable airmass across the North Island we will see the shower activity increase with isolated to scattered thunderstorms developing from Northland to Waikato to Manawatu/Wairarapa. Thunderstorms also look possible over east Otago. There has been overnight thunder activity over eastern Northland.

From a storm chasing perspective the day looks very messy with a lot of cloud and rain. Can we get some decent day time heating over the Waikato today?

[spwill]

Also some lightning activity showing up North Auckland and the Hauraki Gulf.

Can we get some decent day time heating over the Waikato today?

Probably west is best.

[tgsnoopy]

Not sure if the fog we have today is a good sign or not.

Fingers crossed something will happen this afternoon.

[jamie]

pretty bleak here at the moment. will be watching the sky to see when it starts to clear and break up.

[jamie]

good shower moving south towards hamilton going by the radar.

[Chris Raine]

It is humid 99% , the fog has just lifted , the sun is out and if conditions develop later today will chase any developing storms

[kelhb]

Fingers crossed we get somthing out this way, but not looking positive for us.
Anyone care to take a punt on location today?

Currently 20C and 95% humidity.

[Achten]

I reckon the Hawkes Bay Ranges would be favorable today with possible east ward movement of storms later in the day. Showers have been moving like that over the last days.

[tgsnoopy]

Valid to: 12:00am Sunday 19 December 2010
Issued at: 9:16am Saturday 18 December 2010


A very humid northerly flow covers the country with outbreaks of rain over much of the North Island. There have been a few thunderstorms from Northland to the Hauraki Gulf already this morning and a moderate risk of scattered thunderstorms extends over much of the remainder of the North Island during the day (see chart).
However, from central Northland to Waitomo, Coromandel Peninsula, western Bay of Plenty, parts of Taupo, Taranaki, Wanganui, northern Manawatu and Tararua District there is a high risk of some severe thunderstorms with localised heavy downpours of 25 to 40mm per hour or possibly higher this afternoon and evening.
In the South Island, there is a low risk of isolated thunderstorms this afternoon and evening in inland Nelson also about Southland and eastern Otago.
No other thunderstorms forecast.

[DT-NZ]

skies cleared for abit, really humid out there no wind.

[Vertigo]

thunder heard here in glenfield around 6:30 this morning, but nothing since. looks to have moved on and died off a bit, but more favourable conditions on the way from the NW. metservice is picking a good day for thunderstorms, indeed.

[kaimaikid]

So.......

will there be a chase on this arvo?

[David]

Unfortunately not much surface heating going on here, no sunshine. Getting a light shower now. Dewpoint very high though - around 21C.

[NZstorm]

I'm thinking about heading south this afternoon. The action will be inland but whether there is anything to be seen through all the cloud I don't know. Thats the problem with these saturated airmasses.

[jamie]

yea blue sky about but still mostly cloudy. short bursts of heating is occuring. temp now 24/22 so very very saturated air mass. i would say something will happen but all we are going to see is a mass of black cloud.

I did see mamatus clouds thismorning however.

[borris89]

some storms over the ranges to the south of Hastings.

[Vertigo]

the sun has come out in auckland. good chance for some heating today! i think its all on...

[Tornado Tim]

Severe Thunderstorm warning issued on some small cells down Mahia way:

SEVERE THUNDERSTORM WARNING
TOP PRIORITY FOR IMMEDIATE BROADCAST
Issued by MetService at 02:12 pm Saturday 18 December 2010.
Valid until 03:00 pm Saturday 18 December 2010.
This warning affects people in the following local government areas:
CENTRAL HAWKES BAY.
At 02:00 pm, MetService weather radar detected severe thunderstorms near WAIPUKURAU, ONGAONGA, ASHCOTT, ASHLEY CLINTON, THE RUAHINE RANGES, WAKARARA and MAKARETU.
These severe thunderstorms are moving towards the southeast, and are expected to lie near WAIPUKURAU, HATUMA, ONGAONGA, ASHLEY CLINTON, ASHCOTT and MAKARETU at 02:30 pm and near WAIPUKURAU, WANSTEAD, HATUMA, FLEMINGTON, TAKAPAU, ONGAONGA, ASHLEY CLINTON and ASHCOTT at 03:00 pm.
These thunderstorms are expected to be accompanied by very heavy rain.
Very heavy rain can cause surface and/or flash flooding about streams, gullies and urban areas, and make driving conditions extremely hazardous.
The Ministry of Civil Defence and Emergency Management advises that as storms approach you should:
- Take shelter, preferably indoors away from windows;
- Avoid sheltering under trees, if outside;
- Move cars under cover or away from trees;
- Secure any loose objects around your property;
- Check that drains and gutters are clear;
- Be ready to slow down or stop, if driving.
During and after the storm, you should also:
- Beware of fallen trees and power lines;
- Avoid streams and drains as you may be swept away in flash flooding.
This warning is due to be updated or lifted by 03:00 pm Saturday 18 December 2010.

[David]

Getting a good rain shower here, not very heavy though at all - would expect heavier from a CB? Or, maybe it's not a CB...anyway 4mm in the last 40 mins and rising

[spwill]

Plenty of storm action south of Taupo, not much north of Taupo.
Messy weather for the Auckland area, a lot of cloud cover, the odd shower and a fresh NE. A sunny day today would have pulled in a west/sw breeze along the West coast and created a thundery convergence line.

[DT-NZ]

Sun's out and the skies are blue here at the moment - snapped this pic a couple of hour's ago, still humid and warm out there - driving around the countryside's looking suddenly greener.

[spwill]

Given the cloud cover and fresh NE I think the best chance for a storm chase today was down Waitomo way, too far for me.

[NZstorm]

Yes I agree, the Thunder risk looks pretty much finished now for Auckland.

[Chris Raine]

We have Cb's in North Otago around Palmerston and large Tcu over the Kakanui's . maybe something to look at later this afternoon

[pomem]

Thunder currently in Napier