Weirdly changeable spring weather

Sun, snow, sleet, hail, wind - the region has been taking a pounding from some very volatile spring weather.

In Ohakune and Taihape it's been very cold, with fitful snow or sleet. A Whakapapa ski area spokeswoman called Thursday's weather "bizarre".

"The morning was looking quite dreary, then the sun came out and it was a nice day for three hours. Now the winds are picking up and it's been pretty steady snow all day."

The lower slopes of the ski area were closed due to wind during the morning.

There was snow on the road to Whakapapa Village that morning, but it was open to traffic.

Other roads were closed for a time that morning - between Ohakune and Waiouru, between Waiouru and Taihape and between Waiouru and Turangi.

All were open during the afternoon, but may be closed by more snow overnight. Drivers were warned to take care.

In Whanganui wind was the main problem. Gusts of the southerly rose to a high of 89km/hour over Wednesday night, and Whanganui's Fire Service were called to an insecure sign in central Whanganui around midnight.

At 8.30am the crew was out again, securing flashing on a Guyton St building in 59km/hour gusts.

A non-weather related callout was to Pungarehu Marae on the Whanganui River Rd at 10am. Station officer Shane Dudley said a young lady had driven a vehicle into a powerpole, but was unhurt.

At 11.25 the crew was called to Castlecliff, to secure the roof of a house against the gusts.

National Institute for Water and Atmospheric Research scientist Chris Brandolino said the unstable weather was typical for spring - though it did not feel spring-like.

The causes were a mixture - a surge of cold southerly air crossing the country, warm ocean temperatures and a stronger sun angle creating thermals. The combined effect was to create pockets of buoyancy and make air rise quickly.

"The temperature difference creates lift and moisture and instability," he said.