December 2022 Forecasts And Discussions

[HarrisonSasquatchWx]

Stratospheric PV continues to take a major hit in long range modelling in early January. If blocking is favourable there should be plenty of cold air moving south later in the month

Can some explain what it means in regards to the PV taking a hit, to me l would think it means El Nito is destroying it with his pineapple machine.

[PortKells]

Kinda weird to think its only been one week since we woke up to the biggest dump of champagne powder since god knows when. What a day that was!

And now all that's left is a few slices of dirty ice. Should all be gone within a few hours.

[HarrisonSasquatchWx]

Some photos from the Vanderhoof and from Purden ski hill

Awesome shots Ty my man, fantastic you were able to include the have bike will travel it's your signature shot.

[Canada Goose]

https://twitter.com/SurgeBC/status/1607 ... _Xbkh7vYUQ

[HarrisonSasquatchWx]

Just a reminder forum friends to post your snowfall totals for the Dec 22/23 event.

[Bonovox]

Can some explain what it means in regards to the PV taking a hit, to me l would think it means El Nito is destroying it with his pineapple machine.

A purely rudimentary explanation, but as the Stratosphere warms suddenly, you get waves that ascend into the stratosphere and break on top of the polar vortex. Sometimes this can weaken, dislodge or even split the polar vortex. This can then prevent the coldest of air from being locked up in the higher latitudes and allows it to be displaced more easily into the mid latitudes.

[AbbyJr]

A purely rudimentary explanation, but as the Stratosphere warms suddenly, you get waves that ascend into the stratosphere and break on top of the polar vortex. Sometimes this can weaken, dislodge or even split the polar vortex. This can then prevent the coldest of air from being locked up in the higher latitudes and allows it to be displaced more easily into the mid latitudes.

Excellent explanation.

I will add that a sudden stratospheric warming event also has a profound effect on the 500mb pattern. This can in some cases lead to a prolonged arctic blast in the Pacific Northwest but it can also lead to an arctic blast back east. Sometimes, as in the case of February 2019, the cold initially goes east and then it moves west as the blocking ridge retrogrades into the Gulf of Alaska. There are never any guarantees but if we do see a sudden stratospheric warming in January, then my guess is that we will go into another cold and possibly snowy pattern late January or early February. We already have the base state (-ENSO/+QBO) in our favour so a sudden stratospheric warming would only work to help in getting our region cold again this winter. I also expect model chaos to unfold later in the month since models usually struggle with the pattern during sudden stratospheric warming events as they cause such a big shakeup to the large scale upper level pattern.

[Typeing3]

12z GFS ensembles:

ens_image (4).png

12z ECMWF ensembles:

ens_image (5).png

12z GEM ensembles:

ens_image (6).png

[Typeing3]

20221227213208-7b0f3cfd04c1cb14d13fc2a802cdffe4500b18a4.png

[tyweather]

Awesome shots Ty my man, fantastic you were able to include the have bike will travel it's your signature shot.

This is my old mountain bike. I cracked the frame and had it welded back together and now it is living out its retirement up here.

[Typeing3]

Next 15-16 days total precip on the ensembles

12z GEFS (GFS ensembles)

gfs-ens_apcpn_wus_64.png

00z EPS (ECMWF ensembles)

eps_apcpn_wus_60.png

12z GEPS (GEM ensembles)

gem-ens_apcpn_wus_64.png

[Roberts Creeker]

A bit of rain, well, ok, heavy rain all day and...

[Typeing3]

https://twitter.com/Squamishweather/sta ... 9411368961

https://twitter.com/salishsea86/status/ ... 3483209729

https://twitter.com/ensembleator/status ... 4332959744
https://twitter.com/ensembleator/status ... 3058231297

[Typeing3]

1/3

https://twitter.com/coffeekat1144/statu ... 4495963136

https://twitter.com/authorwendy/status/ ... 7291059200

https://twitter.com/alexstuharris/statu ... 3000500224

https://twitter.com/coffeekat1144/statu ... 5013261314

https://twitter.com/theBreakerNews/stat ... 8434834433

https://twitter.com/Smith442Smith/statu ... 6967860226

[Typeing3]

1/3

2/3

https://twitter.com/JamesCybulski/statu ... 9603387392

https://twitter.com/pondering2/status/1 ... 9376568320

https://twitter.com/RobertAlstead/statu ... 9401368576

https://twitter.com/peterprev/status/16 ... 3749780480

https://twitter.com/StevestonShips/stat ... 3468743682

https://twitter.com/naomiyamamoto/statu ... 0101110786