A Severe Thunderstorm Watch has now been issued as a result.
Thunderstorm Outlook:
Thunderstorm Watch:Metservice wrote:Amended at 12:25pm to include all of Taranaki in the moderate risk area.
Daytime heating, low level moisture and sea breeze convergence is expected to generate showers in many inland areas, especially the south and central North Island and the upper South Island. Some of these will be heavy, with a moderate risk of thunderstorms during the afternoon and early evening about inland parts of Buller, Nelson, Marlborough and the far north of the Canterbury high country as well as over the much of central North Island high country extending south to the Tararua Range and also Taranaki as indicated on the map. There is a high risk of thunderstorms about the west of the central North Island high country,Taumarunui and Taihape and parts of Taupo, Waitomo, Taranaki and Wanganui as indicated.
These thunderstorms are expected to be slow moving and hence are likely to produce localised heavy rain of 10 to 25mm per hour. There is also a low risk that one or two of the thunderstorms over the upper South Island will become SEVERE with producing localised downpours of 25 to 40mm per hour. There is a moderate risk of thunderstorms in the high risk area over the North Island becoming SEVERE, producing localised downpours of 25 to 40mm per hour. Rainfall of this intensity can cause localised surface and/or flash flooding as well as make driving conditions hazardous. A watch for severe thunderstorms has been issued.
No thunderstorms or significant convection expected elsewhere.
Metservice wrote: Issued by MetService at Midday Monday 29 December 2014
Valid until 10:00 pm Monday 29 December 2014
This watch affects people in the following weather forecast districts:
Waitomo
Taumarunui
Taupo
Taranaki
Taihape
Wanganui
Intense slow moving thunderstorms are expected to develop this afternoon but weaken later this evening. These storms are likely to be slow moving and could produce localised downpours of 25 to 40mm per hour.
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.
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.
This watch will be updated by: 10:00 pm Monday 29 December 2014
