NZ Weather Forum

Razor wrote:Actually not entirely true spwill while it has been southerly for a couple of hours it seems the action lies to the south still and out to sea

Powermad wrote:MS just lifted their severe thunderstorm warning..

Razor wrote:Actually not entirely true spwill while it has been southerly for a couple of hours it seems the action lies to the south still and out to sea

Powermad wrote:MS just lifted their severe thunderstorm warning..

Powermad wrote:Nope.. coz its gone!

MetService - Severe Thunderstorm Watch

Valid to: 5:30pm Saturday 22 Nov 2014
Issued at: 1:02pm Saturday 22 Nov 2014

MetService Severe T-storm Watch Chart- Is. Nov 22, 1.02pm.png

SEVERE THUNDERSTORM WATCH

Issued by MetService at 01:02 pm Saturday 22 November 2014
Valid until 05:30 pm Saturday 22 November 2014
This watch affects people in the following weather forecast districts:
Christchurch
Canterbury Plains
Canterbury High Country

A very strong and active southerly change moves northwards through Mid and North Canterbury this afternoon, bringing squally showers and possible thunderstorms from about Ashburton northwards. There is a moderate risk of a few SEVERE THUNDERSTORMS with this southerly change across the Canterbury coast and Plains, and about the foothills. These storms may produce large hail in excess of 20mm, damaging wind gusts in excess of 110km/h, and the chance of a small tornado inland. Behind the southerly change, thunderstorm activity will quickly ease. Wind gusts of this strength can cause some structural damage, including trees and power lines, and may make driving hazardous. 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: gullery

This watch will be updated by: 05:00 pm Saturday 22 November 2014

Well it's all over now guys.
Don't forget it's called a Thunderstorm RISK" not a Thunderstorm Actual, so no matter how high the risk is, it doesn't mean it would actually happen anyway, but never mind.
In situations like this and considering the EL Nino spring we are having, one has to be cautious and it is better to be safe than sorry.

cantygal wrote:I heard on the forecast though that it was more than a risk. It was basically a definite with 110km/hr gusts from the south with thunder and hail. A big fail in my books but not unhappy it didn't eventuate

MetService did have a Warning out for gusts up to 110 km/h in some areas, but it never included thunderstorms and hail. The latter was only mentioned in their Watches and Outlooks.

cantygal wrote:These weren't read as watches or warnings but their usual hourly city/regional forecasts.

MetService - Severe Weather Warnings

SEVERE WEATHER WARNING.

ISSUED BY MetService AT 9:10 am 22-Nov-2014

Further heavy rain for the the west of the South Island, the Alps and lower North Island. Northwest gales for central New Zealand.

A front over Fiordland and Southland is moving northwards during Saturday.

This front is preceded heavy rain in the west of the South Island, and also brings a burst of heavy rain to the lower North Island today (Saturday). Heavy falls are still expected in Fiordland till around midday, and in Westland, Buller and about the Main Divide into the afternoon. This includes spillover into the Canterbury headwaters. Streams and rivers are likely to remain in flood, and surface flooding and slips are also possible.

Additionally, strong northwesterlies ahead of the front will affect areas between Canterbury and Hawkes Bay, with severe gales expected in some places. The strongest winds are likely to affect Wairarapa, the hills of Wellington (including the Rimutaka Hill Road) and the Marlborough Sounds. In these areas, gusts of 120km/h or more are possible, which may damage trees, powerlines and can make driving difficult.
...

MetService - Severe Weather Watch

Valid to 9:33am Sunday 23 Nov 2014

SEVERE WEATHER WATCH FOR SOUTHLAND, OTAGO, CANTERBURY, MARLBOROUGH, NELSON, WELLINGTON, HAWKES BAY, TARANAKI

ISSUED BY METSERVICE AT 0933hrs 22-Nov-2014

NORTHWEST GALES FOR CENTRAL AND EASTERN AREAS INTO SATURDAY. HEAVY RAIN FOR OTAGO HEADWATERS, ALSO SOUTHLAND AND MT TARANAKI ON SATURDAY.

A slow moving front near southern Fiordland is forecast to move northwards on Saturday, bringing heavy rain and northwest gales to some areas. Behind the front, a low is expected to deepen just east of Canterbury, resulting in a risk of severe southwest gales about Banks Peninsula, while a rainband moves over the lower South Island.

Warnings remain in force for a number of regions today. This Watch covers a threat of severe weather in other districts as follows:
…

STRONG WIND

CANTERBURY: Northwest gales have eased about the High Country and inland areas north of the Rakaia River, but there is a risk of severe southwest gales about Banks Peninsula Saturday afternoon and early evening.