KEY POINTS:
Dust off your skis this week it's skiing weather! Finally after weeks of heavy snow falls and gales the skies will clear and the winds will ease over most of our ski fields.
Today isn't looking too bad but winds will be strong and there will be
some lingering snow flurries over the Central Plateau and Mt Taranaki. But by tomorrow a big high will move in from Australia clearing the skies and killing the wind as it moves in from the west.
For those of you who know weather you'll know this means some very cold nights are on the way. Lows will fall to near -10 in some central South Island areas with temps dropping to -4s and 5s in inland North Island regions.
The extreme drop in temperatures spells black ice for the roads, so if you are heading off early with the family make sure you take extreme care, even on our biggest state highways, as black ice is invisible. Watch for the 'frosty' road signs and if driving in valleys take particular care wherever the road is wet - it may be frozen.
It was a very cold start this morning thanks to the weekend's polar blast. To explain it to you; with every big southerly cold air is dragged up from well south of New Zealand. Once the storm is over and the low has moved out into the Pacific, the cold air remains over the country and sinks into all the valleys and inland areas. That's why it was -3 in Hamilton and Tokoroa this morning, despite showers moving in. Or -5 across Central Plateau. (Oh and more snow flurries for the State Highway today - they will clear by Tuesday morning).
As the high (anticyclone) moves over New Zealand the skies usually clear - and highs snap lock what we have already - so with the lack of cloud cover that's why we'll see temperatures plummeting at night this week - frosts even possible in Auckland.
The other side of the coin is of course in Summer the high pressure systems snap lock the hot air in place.
So when's the next big system moving in? Well by Thursday nor'westers will pick up over the South Island and winds will increase by Friday over central NZ. The next pool of cold air looks likely to spread over New Zealand briefly next week.
In the meantime - if you want to stay warm but also save power use your curtains to keep the heat in. (For example close them on the eastern and southern side of your home when the morning sun moves to the western/northern side of the house - it really does keep your place warmer!)
And if you're a fan of weather photos, check out all the photos sent by Herald and Weather Watch Centre readers.
Philip Duncan
For the latest weather news keep up to date with The Radio Network's new Weather Watch Centre or the NZ Herald weather section.
Pictured above: Cars and homes under snow in Waiouru. A weekend of freezing temperatures brought snow to the central North Island and caused the closure of roads around Mt Ruapehu. Photo / Sarah Ivey