Stormy Friday with snow, heavy rain, thunderstorms, 120kmh gusts

Friday, 12 October 2018

Heavy snow is expected in Canterbury and Marlborough, while wind gusts up to 120kmh are forecast for the Kaikōura Coast, Wellington and Taranaki on a stormy Friday across New Zealand.

MetService said a complex trough of low pressure was moving northeast across the North Island on Friday. At the same time, a cold front - followed by very cold southerlies - would move up the South Island during the morning, merging with the trough over the North Island in the afternoon.

Snowfall in Queenstown on Friday 12 October 2018.

In Canterbury and Marlborough south of Ward, as much as 30cm of snow could accumulate above 500 metres, with lesser amounts down to about 300m.

'The snow is likely to be heaviest during Friday morning, and during that time the risk of damage to structures such as powerlines is greatest,' MetService said.

Snow could lower to 200m in Fiordland, Otago and Southland, while in the North Island, snow could lower to 800m about Taihape on Friday evening.

On Friday morning, NZ Transport Agency was warning of snow on State Highway 8 from Fairlie to Twizel, and snow and ice on SH73 over Arthur's Pass from Springfield to Otira.

There was a possibility of snow about the Christchurch Port Hills on Friday morning, MetService meteorologist Mark Bowe said.

'What would be rain in normal circumstances, it's producing snow… It's really to do with the really cold air that's being dragged up, when you mix that with precipitation you get snow.'

Severe southerly gales with gusts to 120kmh were expected from about 9am for the Kaikōura Coast, Marlborough Sounds and Wellington. Severe southeast gales with 120kmh gusts were expected in Taranaki from Friday evening to early Saturday.

A rain band moved across much of the North Island overnight and by Friday morning was to the east of Gisborne. 'So that event's over and done with,' Bowe said. A weather station on Mt Taranaki recorded 64mm of rain in the 12 hours to 9am, while another on the western edge of Bay of Plenty picked up 20mm.

Snow falling in parts of the South Island earlier this week.

Periods of heavy rain were recorded at various stations as the band moved across the North Island from west to east, Bowe said.

Rain or showers are expected across the country on Friday, with possible thunderstorms in the west between Auckland and Manawatu, and also in the Bay of Plenty.

Friday will be cold in the South Island, with Christchurch only expected to get to 10 degrees Celsius, while 8C is the maximum expected in Invercargill and Dunedin. In Wellington the high is expected to be 13C, along with the severe southerly gales.

Saturday shows signs of improvement but showers could still fall as snow to 300m about the Kaikōura Ranges, at least at first.

Sunday is forecast to be fine in many places, although a few showers are possible in some areas, and frosts are possible in central parts of the North Island.