The first heavy snow of the season is on the way for much of inland Otago and Southland this weekend, and if the conditions are right, Dunedin and other coastal Otago communities may also get a dusting.
MetService has forecast an active front will move east over the country today, followed by troughs tomorrow and Thursday.
Then a cold front, preceded by strong northwesterlies, is forecast to move northeast over the South Island from the south Tasman Sea on Friday, bringing a very cold air mass to the southern region at the weekend.
Snow is expected in many mountain areas, especially on Friday.
It is likely to be the first heavy snow of the season in these areas and it may lower to levels where it can cause stress to livestock.
MetService meteorologist Dan Corrigan said there was still a high level of uncertainty surrounding the details of the forecast.
"The interesting thing about this snow event is that it’s not the normal cold outbreak southerly surge that we often see that brings all those shower cells northwards out of the Southern Ocean.
"Instead, it’s quite a westerly wind and the cold air comes across the lower South Island from the west.
"So depending on the exact direction of the wind - and there’s a lot of uncertainty in that - it could mean snow for parts of Dunedin if the flow is more southwesterly.
"We can’t give any specific comments on the extent or how low exactly we expect the snow to fall - it’s a bit too early at this stage," Mr Corrigan said.
At the moment, MetService is forecasting snow accumulations to reach warning amounts above about 800m for the Canterbury high country south of the Rangitata River, and for Otago west of about Alexandra.
Snow is forecast in Twizel (Friday-Monday), Omarama (Friday and Saturday), Queenstown (Saturday), Wanaka (Saturday and Monday), Alexandra (Monday), Middlemarch (Saturday) and Invercargill (Saturday), and temperatures could drop as low as -6degC.
Mr Corrigan recommended people keep a close eye on the forecast for any changes or additions in the coming days.
"One thing that seems very likely is that the wintry weather system coming at the end of the week has the potential to bring the lowest snow so far this year for parts of the South Island."
Wet on the West Coast
A heavy rain warning is in place for the West Coast until Thursday, MetService said today.
For Buller and Westland, north of Greymouth, expect 120mm to 180mm of rain from 12pm tomorrow until 5pm on Thursday.
Periods of rain and possible thunderstorms were forecast tomorrow morning, but the most significant rain would begin about midday.
Meanwhile, a heavy rain watch is in place for Westland about and south of Greymouth, from 9am today until 3pm on Thursday.
Periods of heavy rain with thunderstorms are possible. Rainfall amounts may approach warning criteria, especially about the ranges. More heavy rain is possible on Friday and at the weekend.
In Fiordland, periods of heavy rain are forecast until 6pm today, with thunderstorms possible.
- additional reporting ODT Online
