NZ Weather Forum

Valid to 9:55am Sunday 29 Dec 2013

SEVERE WEATHER WATCH FOR NORTHLAND, AUCKLAND, COROMANDEL PENINSULA, BAY OF PLENTY ROTORUA, GISBORNE

ISSUED BY METSERVICE AT 0955hrs 28-Dec-2013

BURST OF HEAVY RAIN FOR THE NORTHEAST OF NORTH ISLAND TONIGHT AND SUNDAY.

A low over the Tasman Sea will spread a very moist and unstable northerly airstream over the upper North Island during today and Sunday. Fronts associated with this low should bring a burst of heavy thundery rain to the upper North Island.

The heaviest falls are likely in Northland this evening and early Sunday morning and in Auckland during Sunday morning and about the Coromandel Peninsula Sunday morning and early afternoon. For Bay of Plenty and the northern and western ranges of Gisborne the heaviest falls are likely during Sunday and early Monday morning.

This Watch is for the possibility of rainfall accumulations reaching warning criteria in these areas.

A few isolated areas may possibly reach warning amounts due to the embedded convection (especially in Bay of Plenty and the ranges of Gisborne), but at this stage models indicate that the rainfall distribution is not widespread enough to warrant a full warning.

MetService will continue to monitor the situation and advises people to keep up to date with the latest forecasts in case any areas in this Watch are upgraded to a full Warning.

This Watch will be reviewed by 9pm Saturday 28 December 2013

MetService - Severe Thunderstorm Outlook

Valid to: Noon Sunday 29 Dec 2013
Issued at: 10:12am Saturday 28 Dec 2013

An active front is expected to move across Northland and Auckland, and onto the Coromandel Peninsula and western Bay of Plenty during the morning, bringing a burst of heavy rain as detailed in latest SEVERE WEATHER WATCH. There is a high risk of embedded thunderstorms with this front, with may produce localised rainfall rates up to 25mm/hr. A lesser risk of thunderstorms extends over Waikato and eastern Bay of Plenty. Sea breeze convergences are expected to develop showers over the Fiordland Lakes and Southern Lakes regions late morning, with a low risk of one or two thunderstorms.

No thunderstorms expected over the remainder of New Zealand.

MetService T-Storm Outlook to Noon 29th - Is. Dec 28, 10.12am.png

Valid to: Midnight Sunday 29 Dec 2013
Issued at: 10:19am Saturday 28 Dec 2013

The active front should bring a burst of heavy rain to Coromandel Peninsula and Waikato in the afternoon, and to the Bay of Plenty during the afternoon and evening. See the latest SEVERE WEATHER WATCH for details. There is high risk of embedded thunderstorms with this front, which may produce localised rainfall rates of 25mm/hr. A lesser risk of thunderstorms extends across Waitomo, Taranaki and Taupo with the passage of this front.

Behind the front, afternoon convergence zones are expected to set up across Waikato, Auckland and southern Northland, bringing a few heavy showers and a low risk of thunderstorms.

As a low approaches Northland at night, heavy showers are likely there, along with a low risk of a few thunderstorms.

Over the South Island, sea breeze convergences are expected in the south and west, along with cold temperatures in the upper atmosphere. There is a moderate risk of thunderstorms across western parts of Southland and the Otago Southern Lakes, which may produce localised rainfall rates of 10 to 25mm/hr. A lesser risk of thunderstorms extends over the Southern Alps.

No thunderstorms expected over the remainder of New Zealand.

MetService T-Storm Outlook to Midnight 29th - Is. Dec 28, 10.19am.png