"It will be cooler than it has been, because the south-westerlies do come from a cooler direction than the north-easterlies do."
Mr McDavitt said showers could be expected in the Auckland region on Saturday morning and Sunday afternoon, but there should be fine weather in between.
Meanwhile wild winds sweeping across the country have brought down trees and powerlines as forecasters warn of gusts of up to 140km/h.
Severe northerly gales hit parts of the central North Island and Nelson overnight and severe north-westerly gales were moving across Wellington, Wairarapa and the Marlborough Sounds this morning.
The wild weather was expected to spread to the Kapiti Coast, Manawatu, Tararua and central and southern Hawke's Bay this afternoon.
Forecaster Andy Downs warned potentially destructive wind gusts of up to 140 km/h were possible.
Police southern communications spokesman Trevor Cross said the wind had brought down a number of trees on the West Coast overnight.
"It must have gone through with a fair bit of force, there were quite a few trees down around the Westport area,'' he said.
The felled trees had been dealt with by local councils and roading authorities.
Trees had also been brought down north of Auckland and in Lower Hutt, and powerlines had come down in Wairoa, but there was no significant damage.
Meanwhile, a burst of heavy rain was expected on the west of the South Island, from northwest Nelson to the glaciers, and the Canterbury headwaters north of the Rangitata River.
Mr Downs warned rainfall of up to 25mm an hour could cause rivers and streams to rise rapidly.