Wyoming Whipsaw Followed By Arctic Attack

Alberta clipper systems often usher in bouts of arctic and polar air to the lower 48 states, but a slightly different type of transcontinental system is evolving as I type; a Wyoming bred whipsaw if you will!  Once this vigorous little system races eastward to the Atlantic and "bombs out" when  fueled by greater water vapor, then the weather community will be watching the invasion of cross polar air into the CONUS.  As for us here in the KMDT region, a few festive flakes will likely fall during midnight mass, but for all practical purposes, the greatest impact from this whipsaw will be to our north and east giving the ski country of New England a solid start for their holiday week!  Take a look at the current watches and warnings associated with this fast little mover...

Note the lake effect warnings on the lee of Erie, Ontario, and Michigan, along with the wind chill warnings and freezing spray warnings on/around Superior!  Winter's harshness will be felt for those hearty souls up on the Keweenaw peninsula with wind whipped snows totaling 1'-2' with the arctic air invasion.  For us, the true arctic air will be slow to move in as we are and will be under broad WSW flow as seen by the current mid-level water vapor imagery!  (By the way, I love the new GOES 16 satellite!)

You can see the arctic air pressing south across Montana and ND and the arctic temps plunging south into the lower 48. Note the warmer temps north of AK and the cross-polar slide south into Ontario and Manitoba!  Brrr....

All compliments of this convoluted jet stream...

This will make for a rather cold week for most of the CONUS less the 4 corners region, California, NV and the Rio Grande Valley. (If you're traveling to the Fiesta Bowl to root on those Nittany Lions, the wx should be nice!) South Florida too is escaping the "cold" thanks to their sub-tropical ridge of warm air!

Now I know many of you are wanting to know about snowfall.  Here is the current snow depth.  About 39% of the CONUS has at least 1" of snow cover.  By next weekend, that total will be greatly increased; however, it is still a difficult call for KMDT.

 The Euro ensembles and the operational runs are not showing any type of consistency and therefore confidence is low as seen by the spread of low pressure systems.  Clearly a storm is going to develop along the east coast of the US, but timing and location are still "up in the air"!  Another arctic high is building over the O Canadian prairies.  Take a look...

OK...enough.  Merry Christmas y'all!  Enjoy this classic.  These performers are jamming!

Smitty

AA:  A few festive flakes as Santa arrives overnight...then pressing cold for the rest of the week.  Still watching a coastal storm potential for Friday-Saturday time frame...?