Why So Much Snow

Issued at 12:55pm 18-Aug-2008

Why So Much Snow

Since last Thursday there has been around 80 cm of fresh snow on the central North Island mountains and a metre or more on the western slopes of the Southern Alps from Mount Cook northwards.

There are three reasons why these snowfalls have been so heavy.

"Firstly, since mid July the Tasman Sea has been a breeding ground for low pressure systems," said MetService Weather Ambassador, Bob McDavitt. "This in itself is not unusual. What is unusual, though, is the sheer number of large lows that have made their way into the New Zealand region."

"Secondly, these lows have often moved quite slowly, allowing more time for snow or rain to fall.

"Thirdly, during the last week or so a lot of cold air from the Southern Ocean has been drawn north and then over New Zealand, tipping the balance towards snow and away from rain."

Mr. McDavitt added that a severe weather warning is in place for more snow until around noon on Tuesday. "This covers the possibility of more snow showers about Otago Peninsula and Banks Peninsula and a burst of heavy snow affecting the central North Island plateau. Also, from late Tuesday through Wednesday, a cold southerly wind may rise to gale force between Kaikoura and Hawke's Bay and through Cook Strait, bringing enhanced rain that may fall as snow on the ranges."

Travellers visiting these areas should check the latest MetService weather forecasts and warnings at www.metservice.com or through the media.

ENDS

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