Snow in forecast for ski fields

Warm northwesterlies are expected to bring a big dump of snow to southern ski fields at the start of school holidays, after southerlies brought snow to Canterbury during the week.

Some weather models were showing up to half a metre of snow falling in the Southern Lakes ski fields during the weekend, as the weather came in from the northwest, MetService meteorologist Tom Adams said.

In Canterbury, Mt Hutt ski area, which is also open, was reporting

12cm of snow in the previous 48 hours yesterday morning.

Coronet Peak, near Queenstown, is also in business. It reported no snow in the previous 24 hours.

The Remarkables, also near Queenstown, is due to open today. Yesterday morning it was reporting

15cm of snow in the previous 24 hours.

In a Facebook post, the MetService’s Adams said that while a cold winter with lots of cold polar outbreaks could bring snow to low levels, a good winter for the ski fields also meant plenty of warmer northwesterlies.

‘‘This is because of the old adage that warmer air holds more moisture. For low-lying areas that just means more rain, but if you go higher into the mountains it eventually will be cold enough for snow,’’ Adams said.

’’When a polar surge hits there is often snow during the onset as the cold air advances under warmer air, but then not much afterwards because the air is too dry.

‘‘These overrunning situations often are best for Canterbury ski areas.

‘‘In contrast, northwesterly winds can bring an atmospheric river of warm, moist air over the country from the north Tasman sea, and this can stick around for days,’’ he said.

‘‘This prolonged precipitation will end up dropping far more snow overall, especially in the Alps and the Southern Lakes ski areas.’’