December 2020 Forecasts and Discussions

[AbbyJr]

Hard to imagine this modelled SSW event not verifying. We have the Euro, GFS, and GEFS all on board.

Notice how identical all three models look in both position, strength, and timing.

That said, we don't always have the best luck. Hopefully this time it will work out in our favour.

ecmwf-deterministic-nhemi-t10_anom-9416000.png

gfs-deterministic-nhemi-t10_anom-9416000.png

gfs-ensemble-all-avg-nhemi-t10_anom-9416000.png

[Michael1]

Hard to imagine this modelled SSW event not verifying. We have the Euro, GFS, and GEFS all on board.

Notice how identical all three models look in both position, strength, and timing.

That said, we don't always have the best luck. Hopefully this time it will work out in our favour.

ecmwf-deterministic-nhemi-t10_anom-9416000.png

gfs-deterministic-nhemi-t10_anom-9416000.png

gfs-ensemble-all-avg-nhemi-t10_anom-9416000.png

I like this post better than Chris Doyle's lol

[John]

I like this post better than Chris Doyle's lol

Chris Doyle kind a sucks. Tyler Hamilton is better

[Michael1]

Chris Doyle kind a sucks. Tyler Hamilton is better

Lol, that's the spirit !

[Typeing3]

Looks like YVR didn't receive any snow yesterday. If it holds, we could be looking three completely snowless Decembers in a row (not even trace amounts were recorded in 2018, 2019 or thus far in 2020) for YVR which would be a record.

1900-1901-1902 and 1939-1940-1941 are the only other three year periods that come close to matching up to this in the period of record for Vancouver - though one December out of the three in both cases did record trace amounts of snow.

[Typeing3]

Temps are dropping off pretty fast this evening.

Currently 1.7c after a high of 5.4c earlier.

[Rubus_Leucodermis]

Currently at the freezing mark here. High of 3ËšC.

[wetcoast91]

NWS and EC going with a mixed precip scenario in that Sat to Mon period.

Very interesting to see how our version of a "cold pool" forms below 500m in the next few days. Splitting jet brings in very weak systems but low level flow appears to remain offshore. This could bring snow to Hope and Eastern Chilliwack with freezing light rain in Chilliwack, Sumas and Abbotsford.

[Typeing3]

Wow, Abbotsford already at -2c.

[Typeing3]

NWS and EC going with a mixed precip scenario in that Sat to Mon period.

Very interesting to see how our version of a "cold pool" forms below 500m in the next few days. Splitting jet brings in very weak systems but low level flow appears to remain offshore. This could bring snow to Hope and Eastern Chilliwack with freezing light rain in Chilliwack, Sumas and Abbotsford.

Snowcover from yesterday's system will really help establish that cold pool in the interior.

If we see a similar setup to yesterday sometime down the line, our access to cold air should be a lot easier.

[Typeing3]

Saturday could be interesting in the valley. Outflow and cool surface temps. Upper level temps look marginal so ZR is a definite possibility.

[wetcoast91]

Saturday could be interesting in the valley. Outflow and cool surface temps. Upper level temps look marginal so ZR is a definite possibility.

Depth of cold air goes up to 2000m so this would be all snow to the rain-snow line where it would be freezing rain. West of that boundary? Freezing level looks to skyrocket near 1800m. Could be a day where Cypress sees rain while Abbotsford sees snow.

Precip also looks sufficient but light enough with no real strong onshore push to dislodge the cold surface layer.

[John]

Wow, Abbotsford already at -2c.

Could see a -10 somewhere with snow cover clear and wind sheltered long night

[John]

Depth of cold air goes up to 2000m so this would be all snow to the rain-snow line where it would be freezing rain. West of that boundary? Freezing level looks to skyrocket near 1800m. Could be a day where Cypress sees rain while Abbotsford sees snow.

Precip also looks sufficient but light enough with no real strong onshore push to dislodge the cold surface layer.

How much snow for chilliwack?

[Typeing3]

Could see a -10 somewhere with snow cover clear and wind sheltered long night

-10c seems a stretch but a few -6/-7c readings are possible.

10-20cm of fresh snow and 850mb temps are around -4c in the valley. Calm winds will be key to maximizing min temps tonight.