The weather pattern takes a dramatic turn next week as high pressure clears away and large windy lows move in.

The first day of winter on the meteorological calendar looks wintry with perhaps the first real nationwide southerly of the year coming in, says WeatherWatch.co.nz

"While we can't lock in precisely the conditions for June 1, the models we trust most certainly suggest there is a moderate to high chance of a low deepening around NZ and a much colder surge of southerlies at the end of next week and going into next weekend.

"The large high that is over New Zealand right now will remain early next week for the North Island but it slips off the South Island on Sunday allowing windy westerlies to move in. The North Island becomes a little windier on Sunday too (mainly in the south) but it's not until Monday that the high properly slips away to the east."

Tuesday sees another surge of strong winds over the South Island while the North Island has a brief breather.

By Wednesday next week, severe weather is possible in the South Island with heavy rain continuing and strong to gale force nor'westers moving up to Cook Strait, says the weather organisation.

"Over Thursday and Friday low pressure deepens over New Zealand and this will suck up a likely wintry southerly with cold weather, heavy rain, snow on the mountains and strong to gale force winds in some places.

"There are quite a few moving parts, especially towards the end of next week, so expect some changes - but either way next week is looking very different to this week due to a big uptick in low pressure."

June 1 is the first day of winter on the meteorological calendar. June 22 is the date this year for the astronomical start to winter (the shortest day of the year).