No, this one's odd. Moved in from the south, and keeps on coming, running into the polar high off to the northwest. I guess the whole thing is being held stagnant by a polar high over Greenland, and that's screwing with folks all the way east to the coast.
This one at least as at the onset has the same meterorlogical tendencies to what all of us went through on Christmas of 1983 and 1989. Cold and Snow watchers need to be keen to the directional vector of polar high as it plunges southward late next week. If we see are more North-South movement, vs. say NW to SE, you'll see the core of 31+ barometric settling alot further south. And that will translate to brutal cold. Seeing 31+ scooting the Candadian- U.S. border than say Oklahoma/Tx Panhandle will make maybe 20-30 degree difference on how this plays out.
Secondly watch for what I call the valleys of Bar. Press, around placed highs in these cold outbreaks. These tend to be where we see the great big snows. Those pesty upper level lows that dump a dusting to 6" generally can't survive mountains of cold air in the atmosphere, due to most all additonal moisture being squeezed before becoming frozen convection.
Taking a look at the most recent GFS run------>.
https://www.tropicaltidbits.com/analysis/models/?model=gfs®ion=us&pkg=mslp_pcpn_frzn&runtime=2022121506&fh=132Polar high core reaches the CONUS (Continental United States) border at mid day on the 20th as a 1061Mb high (wow-Barometric Pressure of 31.31) in a (at first) Montana to Kansas vector.
Through the 21st, it continues a SE, then southward plunge, targeting the plains with core. Precipitation looks sparse, as the lows at the moment are pushed to along the FL and SC coasts.
Through the 24th, and I see this is big, is that the high stalls around the Dakotas and moderates. This possibly could spare the South and the midwest record breaking cold. In fact a 1035Mb high comes on shore in CA, that is not that much lower than our artic high, which at least in this part of the run is at 1044Mb. With that....... There is a real tight pressure gradient between the two highs located Western Nebraska, Western Kansas, and Eastern Colorada. That kind of setup may create huge snows.
By late Christmas Eve and actual low has formed in Nebraska that moves eastward around the north of the High that has moderated (1034Mb) This run would indicate big snows from a line say the...... Central ND border through about Omaha Nebraska. Precipatation in the S, SE, and Midwest looks pretty sparse.
On Christmas, the low seems to stall over Missouri, and southern IL. I sure hope these models aren't accurate for them. 24 hours of heavy snow? Yikes. The artic high itself, lifts to the NE.
Through the 26th, apparently there is enough residual moisture, and cold air to show some minor snow and ice for Mississippi, Alabama, and southern GA, as a Noreaster looking low seems to be forming off the SC coast.
Again... a warning.... This is model data 7-11 days out. Just like hurricanes, these are guesses, and not typically accurate. But, from seeing upper air patterns, and what we are seeing in the Yukon right now, I do think it is a pretty safe bet that everyone from the Continental Divide eastward is going to see some pretty damned cold weather, and a good chance we'll see snows and White Christmases, where we don't normally see them.
And p.s. to NE Briefers...... Same model shows a 974 Mb Noreaster off the east coast by the 28th. It's proximty to that location, will be huge.
Stay tuned.
