Warning: GALE warning for COOK for Friday GALE warning for STEPHENS

Situation: A strong southwest flow over New Zealand weakens on Saturday as a narrow ridge moves onto the country from the Tasman Sea. A trough crosses the South Island on Sunday and the North Island on Monday, followed by another ridge.

Forecast: Strong wind advisory. Thursday: Variable 5 knots. Westerly 10 knots developing this afternoon and rising to 20 knots gusting 30 knots this evening but 25 knots gusting 35 knots north of Otaki. Smooth sea becoming slight this afternoon then moderate this evening but rough in the north. Fine weather. Friday: Westerly 20 knots gusting 30 knots but 25 knots gusting 35 knots north of Otaki, turning southwest 20 knots gusting 30 knots everywhere in the afternoon, then easing to southwest 15 knots in the evening. Moderate sea but rough in the north, becoming moderate everywhere in the afternoon, then slight in the evening. Fine and cloudy periods.

Outlook: Outlook until midnight Monday: Saturday: Southwest 15 knots, dying out overnight. Mainly fine,chance shower. Sunday: Northerly 10 knots developing in the morning, dying out at night. Becoming cloudy, a few showers developing. Monday: Southerly 10 knots. Becoming fine.

Swell: Swell forecast to midnight Monday: Northwest half a metre, rising to 2 metres overnight tonight, gradually easing to half a metre on Friday, dying out on Saturday.

High tide at Karehana Bay
Time: 7:30pm Thursday 17 May 2012 - Height: 1.2m
Time: 7:40am Friday 18 May 2012 - Height: 1.2m