qg_omega

It’s not like some here haven’t warned about this pattern since November with the block pushing the PV to western Canada

No reason to discount the persistent trough in the west. Those 10 day plus ensemble maps are useless and not a reason.

2 inches in white plains (west Harrison)

Where?

Wish we lived at 500mb

This looks good

Ukmet has a warm coastal

The retrograding 50/50 controls next weeks threat

Many places had that a few weeks ago

Yup 26 inches of snow with 60 mph winds, awful

12z EPS for Dec08 and Dec12: Blocking in Greenland is not wildly off, however the PNA domain was very wrong which changes everything. Instead of having a PV under the block, it is now over Western Canada and the SE ridge is able to link up to the blocking. This is exactly what I was concerned about on November 27th: SSTs support the -PNA regime and I have no faith in any ensemble trying to break down the -PNA.

DT as well

January looks like a torch

Blocking incoming:

Brutal cold is north of Montana and locked up

yes, nothing like that this month with the PV in BC.

As I have said for the past month, ensembles have extremely low skill past 10 days and should not be used to forecast. The current pattern makes it even more difficult to use them. Look at the EPS forecast from 0z for +84: https://www.tropicaltidbits.com/analysis/models/eps/2022120500/eps_z500a_namer_15.png Compared to the EPS forecast for the same period but + 192 + 252 https://www.tropicaltidbits.com/analysis/models/eps/2022113012/eps_z500a_namer_33.png + 252 https://www.tropicaltidbits.com/analysis/models/eps/2022112800/eps_z500a_namer_43.png The PV is not caught under the block as forecasted but instead is heading into BC with a much stronger -PNA. Also the ridging is connected from the SE into Greenland resulting in a warm cutter pattern. Exactly as I warned a few weeks ago, you need the pattern shifts to move forward in time and just because the NAO is negative, doesn't mean much if a pacific airmass is trapped under the block, even for NNE.

Always take the cold, always

The EPS has been atrocious, especially on the PAC forecast

In this pattern with short wave lengths and lots of blocking, I would suspect correlation coefficients near 0.2 or worse in 10 to 15 day ensemble range. Would easily bet on an opposite look of that today

Can’t imagine anyone doing good in the next three weeks, the pattern screams rain to Maine. There is no cold air under the block and the PV is gone. One of the worst patterns we have seen in December in many many years. Hard to get 5 straight rain events in NNE in December but that’s on deck