December 2020 Forecasts and Discussions

[HarrisonSasquatchWx]

Have yourself a merry little Christmas

Signed 2020

Probably John's red nose Cathead.

[PortKells]

I am #8

Maybe time to call er a night?
Euro is...ok in the medium range. Definitely different than the GFS.

[Typeing3]

The Greenland block did not cause any issues for us in the December 1968 arctic blast. Here is the 500 mb pattern for December 28, 1968. Abbotsford recorded a high of -16.7 and low of -18.3C.

12281968.gif

It was a massive Greenland block that extended well west into Nunavut and the Hudson Bay. Coupled with the broad Aleutian/Alaskan block, the PV was funneled southwestward into western Canada.

Without the west based -NAO, the core of the arctic air would have likely been over the prairies.

[AbbyJr]

It was a massive Greenland block that extended well west into Nunavut and the Hudson Bay. Coupled with the broad Aleutian/Alaskan block, the PV was funneled southwestward into western Canada.

Without the west based -NAO, the core of the arctic air would have likely been over the prairies.

So what you're saying is the current Greenland block isn't identical to the 1968 one?

[John]

Maybe time to call er a night?
Euro is...ok in the medium range. Definitely different than the GFS.

Ok good night

[Typeing3]

So what you're saying is the current Greenland block isn't identical to the 1968 one?

Yep. We'd need to see the block extending westward towards the Nunavut/NWT border. Right now it's not that close...lower than average heights are still over Hudson Bay.

gfs_z500a_namer_17.png

'68-69 had some pretty extreme high latitude blocking. The AO value must have been tanked most of the winter.

[AbbyJr]

Yep. We'd need to see the block extending westward towards the Nunavut/NWT border. Right now it's not that close...lower than average heights are still over Hudson Bay.
gfs_z500a_namer_17.png
'68-69 had some pretty extreme high latitude blocking. The AO value must have been tanked most of the winter.

Interesting, thanks for the insights. Regardless, if the SSW verifies, the long range models right now would likely be useless. Hope for the best but prepare for the worst in our climate.

[stuffradio]

Happy Christmas Eve! Try not to have too much Egg Grog tonight!

[Rubus_Leucodermis]

Clear and -4.4ËšC.

[PortKells]

Really nice morning. Moderately negative PNA in the long range but no favorable blocking. Ssw continues to get pushed back. If we are waiting on that for an arctic blast then IMO February it is.

[Monty]

Really nice morning. Moderately negative PNA in the long range but no favorable blocking. Ssw continues to get pushed back. If we are waiting on that for an arctic blast then IMO February it is.

I haven’t been tracking that closely looks like it’s about 10 days away on the GEPS and has been moving up. PV is gone by the end of week 2.

[PortKells]

I don't want to get ahead of myself but...Is this the least crappy December since 2017??

[PortKells]

I haven’t been tracking that closely looks like it’s about 10 days away on the GEPS and has been moving up. PV is gone by the end of week 2.

Kinda looks like pacman ate it up.

PV split Dec 24.png

[wetcoast91]

I haven’t been tracking that closely looks like it’s about 10 days away on the GEPS and has been moving up. PV is gone by the end of week 2.

I always joke about mild rain however I fully expect late Jan and Feb to be absolutely miserable. Periodic periods of moisture with low freezing levels. Keep thinking of a chillier 2007-2008 for that reason which gets over shadowed due to what followed in 2008-2009.

[PortKells]

I always joke about mild rain however I fully expect late Jan and Feb to be absolutely miserable. Periodic periods of moisture with low freezing levels. Keep thinking of a chillier 2007-2008 for that reason which gets over shadowed due to what followed in 2008-2009.

I've said this before but this is an absolutely terrible year for such a fantastic ski season.

GFS ensemble dec 24 12z.png