The latest on Cold Snap + Maps
We invite anyone with any questions on the upcoming Polar Blast to please leave us a comment below - we will work through the comments throughout the day so please check back.
Significant uncertainty remains regarding the Cold Snap that is headed our way as we progress through next week, however we have increasing confidence with snow levels on Tuesday.
As you can see from our Significant Weather Outlook issued Friday evening, we have increased our confidence for Significant heavy snow from a SLIGHT risk to an ENHANCED risk above 500 metres for the Canterbury High Country, Inland Otago and Northern Southland on Tuesday as indicated. We are also anticipating rain for many regions of the South Island, and could be particularly heavy for Dunedin, Coastal Otago and Southern Canterbury as indicated.
“There is significant uncertainty as we progress from Wednesday - we urge everyone to keep a very close eye on upcoming updates.”
There are alot of moving parts with this upcoming weather system from the developing low pressure system in the Tasman Sea, to the placement and shape of the High Pressure system near Tasmania and whether the cold air will arrive in meet the incoming moisture originating from the Sub Tropics - or even be cold enough for sub alpine snow
On Wednesday our confidence diminishes, with a split between weather models as to whether we can expect to see moisture cointuing to feed in from the southeast, or whether the developing low pressure system will be situated in a way that moisture (rain/snow) clears out for most places.
Here are three different weather models showing total snow accumulation up until Wednesday evening - as you can see there are varying outputs for both snow levels and snow totals, showing you just how tough of a job we as forecasters have at the moment trying to make an accurate forecast.
Our Current Forecast:
We are expecting to see snow lower late on Monday evening or Tuesday morning, down to 400 metres for Southland, Otago and South Canterbury, and to about 500 metres for Inland Mid Canterbury.
Alpine Passes are likely to be affected by snow, and may lead to closures.
Moderate wind chills are expected from Tuesday - this event is expected to linger bringing cold temperatures until atleast Thursday.
That is all for now, please leave a question in the comments box if you have one and we will reply back as soon as we can so please check back.
Severe Weather NZ Forecast team.
