Snowfall Warning Issued – 10-20cm – possible Freezing Rain

Final Update 9PM Sunday

The warm winds have come. We have gone from 0°C to 4°C in less than 30 minutes and the wind has switched to the SSW. Strong winds are reported on the East side. 50-60kph at Hornby Island.

Expect the Snowfall Warning to be lifted soon.

Update 12PM

Drizzle is starting in some parts of town, ice pellets at Alberniweather. Totally dependent on local temperature and how hard it is precipitating. Heavier it is, more it will cool the air and turn to snow as long as we are within a degree or two of freezing.

Snow now in earnest as warm advection aloft ramps up this pm and brings heavier snow to #YVR, Valley, colder inland parts of VI this pm pic.twitter.com/oSoB0gC9L5

— Chris Doyle (@ensembleator) December 18, 2016

Update 9AM Sunday

We received just a small amount of snow overnight but the main precipitiation is still yet to come. EC expects us to stay at or below freezing and for everything to fall as snow until later tonight.

It should begin to snow more heavily around noon and then pick up steam through the rest of the day and also gradually warm. Strongest precipitation will be tonight around 3AM. That should be past the point of warming and should be rain. We shall see.

Stay safe on the roads. So far, they are pretty good.

Latest radar showing a band of snow over central Vancouver Island #BCstorm pic.twitter.com/vPgCsgeW4P

— Yvonne Schalle (@YvonneSchalle) December 18, 2016

https://twitter.com/alberniweather/status/810345314443923456

I think by that time the warm air will have overrun the island; you don't have the (dis) advantage of being on the continent

— Chris Doyle (@ensembleator) December 18, 2016

https://twitter.com/alberniweather/status/810341579512680448

Given so far clear skies and some cooling this eve, i'm tending to prefer the cool solution https://t.co/TB02rACK5L

— Chris Doyle (@ensembleator) December 18, 2016

This morning's SREF maintains the dual track solution for #YVR snow. #headache pic.twitter.com/ZvQn5v8kTd

— Chris Doyle (@ensembleator) December 17, 2016

Environment Canada has issued a snowfall warning for Port Alberni and all of Vancouver Island except Northern sections.

They forecast 10-20cm of snow but the models are very very uncertain on how the warm air will interact with the entrenched cold air. 5-10cm is expected in coastal areas.

Some models have us above zero right away over night, those are the freezing rain and rainy ones. Others have us staying cold. Those are the snowy ones.

The precip will start after midnight tonight. The short term models that are closer to present time have us warming almost right away and less snow. The longer term ones that are from 10AM today have us cooler and snowier.

I am inclined to go with the broader long term ones that has us snowier, like EC but I would also be very wary of thr possibility of freezing rain in Port Alberni. So be careful out there!

Here are all the different options:

The High Resolution and short term HRRR model has us warming to 2 °C by 7AM Sunday but produces freezing rain overnight tonight into Sunday morning.

The short term RAP is similar.

The Canadian GEM is very different, it expect us to stay cold throuh Sunday and as a result has 12cm of snow falling. This is clearly the one EC is banking on.