December 2021 Forecasts And Discussions

[South Island]

Late next week looks pretty active. We need that Alaskan block to hold a little better and serve to suppress the storm track a little more. Cold air is near by and there is plenty of moisture sliding under the ridge offshore

Ya looks like some lows to our southwest that could possibly pull in some colder air from the interior. Hopefully things stay suppressed.

[Rubus_Leucodermis]

Yeah sea level is not going to get much this weekend

It’s going to be interesting to see which aspect of the models prevails: the recent proclivity to get precipitation type wrong (as if water somehow freezes at +2°C), or their longstanding proclivity to underestimate the tenacity of low-level cold.

I think a measure of caution is the best forecast, i.e. the metro area could possibly see up to 10 cm at lower elevations before it finally transitions. Don’t really get the feeling that forecasting a widespread 20–40 cm would in any way verify (maybe for Pornoman and the Westwood Plateau, but not in general).

[Storm]

Watches

5:01 AM PST Friday 31 December 2021
Winter storm watch in effect for:

Metro Vancouver - central including the City of Vancouver Burnaby and New WestminsterMetro Vancouver - North Shore including West Vancouver and North VancouverMetro Vancouver - northeast including Coquitlam and Maple RidgeMetro Vancouver - southeast including Surrey and LangleyMetro Vancouver - southwest including Richmond and Delta

A significant winter storm bringing a mix of wintery conditions is expected this weekend.

Locations: Metro Vancouver and the Fraser Valley

Snowfall accumulations: Potential for 2 to 10 cm beginning Saturday, with higher amounts near Hope.

Rainfall amounts: Potential for 10 to 40 mm Sunday.

Other hazards: Risk of freezing rain overnight Saturday and Sunday morning. Strong winds Sunday near the Strait of Georgia.

Time frame: Saturday and Sunday.

Remarks: A winter storm will reach the south coast on Saturday bringing a mix of snow, rain, and wind into Sunday.

Snow is expected to begin Saturday afternoon or evening. Overnight, temperatures will begin to rise as warm air advances from the Pacific.

On Sunday morning, the snow will change to rain for Metro Vancouver. Western sections of the Fraser Valley will gradually see a transition to rain Sunday, while eastern sections closer to Hope will continue to see significant snowfall through Sunday.

The exact precipitation amounts and timing of the changeover to rain still remains uncertain at this point.

Additionally, there is a risk of freezing rain as warm air overrides the cold air lurking near the surface overnight Saturday into Sunday.

Strong winds of 40 km/h gusting to 70 km/h will also develop early Sunday, possibly gusting up to 90 km/h near the Strait of Georgia.

Road conditions may quickly deteriorate as snow transitions to rain. Freezing rain may also make surfaces icy and slippery. Snowmelt from the anticipated warming and additional rainfall may cause water pooling on roads and local flooding.

Be prepared for rapidly changing conditions and take extra care when walking or driving in affected areas.

Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to BCstorm@ec.gc.ca or tweet reports using #BCStorm.

[Monty]

It’s going to be interesting to see which aspect of the models prevails: the recent proclivity to get precipitation type wrong (as if water somehow freezes at +2°C), or their longstanding proclivity to underestimate the tenacity of low-level cold.

I think a measure of caution is the best forecast, i.e. the metro area could possibly see up to 10 cm at lower elevations before it finally transitions. Don’t really get the feeling that forecasting a widespread 20–40 cm would in any way verify (maybe for Pornoman and the Westwood Plateau, but not in general).

Not much precip with the warm front being modeled and I’m fairly confident that western sections will rise above freezing Sunday before the heaviest precip arrives. The bigger question is do we see that heavier precip cool the atmosphere from the top down and artificially lower snow levels as the cold front passes. That’s a possibility as it stands now.

[Monty]

Looking a little farther out we are seeing signs of the ridge possibly rebuilding overhead. If we happened to get to that point with some snow cover around and a decent cold pool in the interior we could see a nice stretch of fake cold. Clear frosty nights and possibly sunny days if we can avoid the fog

[PortKells]

Looking a little farther out we are seeing signs of the ridge possibly rebuilding overhead. If we happened to get to that point with some snow cover around and a decent cold pool in the interior we could see a nice stretch of fake cold. Clear frosty nights and possibly sunny days if we can avoid the fog

I've been watching that too. That would be the cherry on top. Of course its always possible the models are missing out on some drizzle but we'll see.

[John]

Not much precip with the warm front being modeled and I’m fairly confident that western sections will rise above freezing Sunday before the heaviest precip arrives. The bigger question is do we see that heavier precip cool the atmosphere from the top down and artificially lower snow levels as the cold front passes. That’s a possibility as it stands now.

What’s your thought for the Chilliwack area this weekend Monty?

[South Island]

Looking a little farther out we are seeing signs of the ridge possibly rebuilding overhead. If we happened to get to that point with some snow cover around and a decent cold pool in the interior we could see a nice stretch of fake cold. Clear frosty nights and possibly sunny days if we can avoid the fog

If that’s the case in the long range then let’s hope for some retrogression after that.

[Storm]

If that’s the case in the long range then let’s hope for some retrogression after that.

End if January

20211231_053852.jpg

[Monty]

If that’s the case in the long range then let’s hope for some retrogression after that.

Some hints of retrogression in the ensembles but we’re talking 2 weeks out

[PortKells]

If that’s the case in the long range then let’s hope for some retrogression after that.

Wow you guys want it all. If this winter never got cold again I think I' satisfied. It feels like this couldn't be topped. But I wouldn't say no either..

[Storm]

oh Judah

https://twitter.com/judah47/status/1476 ... es6sQ&s=19

[Monty]

What’s your thought for the Chilliwack area this weekend Monty?

10-20cm. I’d be concerned of freezing rain on Sunday for a time. Could go back to snow Monday night as the mid levels cool again.

[Storm]

https://twitter.com/YVR__Weather/status ... sHq6A&s=19

[Canada Goose]

https://twitter.com/ensembleator/status ... 91/photo/1