Wild weather: Strong winds and heavy rain as front crosses country

Wind flow map of New Zealand showing a strong (brighter colour) northerly flow over the South Island as an unstable airmass crosses the country from the south-west.

Batten down the hatches, strong winds that blew a bus and a motorcyclist off the road today are set to continue.

Weather warnings cover the South Island and lower North Island, with MetService forecasting heavy rain, strong winds, and snow at higher levels as a front crosses the country mid-week.

Heavy rain and north to northwest gales for Southern and central parts of the country are predicted.

Gusts could reach 130-140km/h as they move up towards Cook Strait over the next few days, and rain will accompany them.

Severe gale wind warnings are in force for Canterbury, Marlborough, Wellington, Wairarapa, Taranaki, Whanganui and Taihape.

MetService warned the ferocious winds could damage trees, powerlines, lift roofs and making driving hazardous.

South Island motorists were advised to take extra care on roads tonight and tomorrow.

Heavy rain warnings are in force for Fiordland, the ranges of Buller and Nelson and Mount Taranaki tonight and tomorrow.

The heavy rain in these areas will cause rivers and streams to rise, and could lead to surface flooding and slips.

Snowfall warnings are in place on Thursday for Lewis Pass, Arthur's Pass, Porters Pass, Lindis Pass, Haast Pass and Milford Road.

It was too windy this afternoon for the driver of a van to be flown to hospital after his vehicle crashed into an irrigation canal in Mayfield, Ashburton.

A fire service spokesman said the driver had to be taken by road to Christchurch hospital.

They were also called out to three vegetation burn-off flare ups near Ashburton, where strong winds had whipped up the flames.

A spokesman said these were under control and the largest was about six hectares.

Ironically, because the ground was so wet there was a worry the fire engines would get stuck in the mud.

"It's windy and wet, but burning," the spokesman said.

Caution is being urged in the back country of the Southern Alps, where avalanches are possible, as snow from the early part of the season has combined with the warmer weather last month to form an icy crust.