NZ Weather Forum

Metservice wrote:A complex trough of low pressure will move slowly onto northern and central parts of New Zealand today, bringing the potential for significant localised rainfalls. Conditions are expected to be unstable over much of the North Island and the extreme northwest of the South Island. There is a high risk of scattered thunderstorms over central parts of the North Island this afternoon and evening,with a moderate risk extending up to Northland and a broader low risk down to Wairarapa and coastal Buller, as indicated on the chart. Any thunderstorms that develop are expected to produce localised heavy rain of 15 to 25mm per hour, hail and also brief strong wind gusts up to 80 km/h. There is also a moderate risk that one or two of these thunderstorms could be SEVERE over central areas producing localised downpours of 25 to 40mm per hour and a SEVERE THUNDERSTORM WATCH has been issued.

No thunderstorms or significant convection expected elsewhere.

Metservice wrote:Issued by MetService at 08:19 am Tuesday 26 November 2013
Valid until 10:00 pm Tuesday 26 November 2013
This watch affects people in the following weather forecast districts:
Waikato
Waitomo
Taumarunui
Bay of Plenty
Rotorua
Taupo
Gisborne
Hawkes Bay
Taranaki
Taihape
Wanganui
Manawatu
Tararua

Scattered thunderstorms are expected to develop over central parts of the North Island this afternoon and evening. One or two of these thunderstorms may be SEVERE producing localised downpours of 25 to 40mm per hour. Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips.

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: Andy Downs
This watch will be updated by: 02:00 pm Tuesday 26 November 2013

NZstorm wrote:Last time we had a thunderstorm set up like this was April 21.
.

Manukau heads obs wrote:some blue patches here now after the passage of the warm front
(with a bit of drizzle)
wind is now NNW here
so missing that NE convergence now

NZstorm wrote: Yes, we need the NE sea breeze to come in. Otherwise its a mainly fine very warm afternoon for Auckland. Temp 24C dp19C currently.

David wrote:Convergence line has started forming from south Auckland down through the Waikato