Severe Weather Outlook – 17/12/12

Severe Weather Outlook – 17/12/12

Issued: 2:39pm Monday 17 Dec 2012
Valid from Wednesday 19 December 2012 to Saturday 22 December 2012

A high should develop over most of New Zealand during Wednesday and move slowly east on Thursday.

A front moving northeast is expected to reach the South Island on Friday bringing rain to the west of the Island. There is moderate confidence that a rainfall warning will be required for Fiordland and southern Westland on Friday. There is also the possibility of spillover into the headwaters of the Otago and South Canterbury lakes and rivers.

Tropical Cyclone Evan is expected to undergo its mid-latitude transition late in the week or during the weekend as it approaches the north of the country. There is still a lot of uncertainty in the forecast strength and track of the resultant low over the weekend. As a precaution, a low confidence of heavy rain and severe gales is indicated in Northland for Saturday. MetService will be monitoring the system carefully as it approaches the country and the latest forecasts should be referred to for up to date information.

Low confidence:
a 20% likelihood (or 1 chance in 5) that the event will actually happen.

Moderate confidence:
a 40% likelihood (or 2 chances in 5) that the event will actually happen.

High confidence:
a 60% likelihood (or 3 chances in 5) that the event will actually happen

New issues of this forecast are made available on this site at or before 16:30NZST

ENDS

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