Auckland boaties are being warned to check moorings as the MetService issued a severe weather outlook with gale force winds likely to lash the region tomorrow.
The warning comes as mainly fine but frosty weather across the country - with temperatures down to 3C in Central Otago yesterday - change to heavy wind and rain over the North Island.
Auckland Regional Council harbourmaster John Lee-Richards said there were two main reasons for boats getting into trouble in high winds.
"There is a pattern of boats coming off moorings. Generally we find it's chaff from the rope or the top rope has been put on incorrectly.
"Chaff is an insidious thing, it sits there chaffing away for weeks and weeks and it's all fine. Then you get 35 to 40 knots and that's when the line breaks.
"It's bye-bye boat unless we get there quickly. Checking saves a lot of heartache later on when boats are a pile of driftwood on the seawall," Mr Lee-Richards said.
MetService forecaster Heath Gullery said today would be a repeat of yesterday's mild and settled weather, but it would be a different story for the next two. A low over the Tasman Sea is expected to deepen rapidly tomorrow and gusts in exposed places could blow from 65km/h to 100km/h.
"During those days there's a good possibility that the upper North Island will see a period of east to southeast gales and possibly a period of heavy rain."
That rain is likely to hit Northland rather than Auckland throughout tomorrow before easing on Monday.
The gales could spread across the rest of the North Island and there is also a chance that the Coromandel would see some of that heavy rain before it moves south through Gisborne and northern Hawkes Bay.