What we call the Polar Vortex (essentially the coldest air in the world) right now is placed over Southeastern Canada. However, this Vortex is so strong, that it is keeping the coldest air closest to the center, as opposed to allowing it to spread out. The Northern United States is feeling this some (Temps in Upstate New York are expected to be 30 below tonight)! However, as the week goes on, this is expected to shift even more to the north. At the same time, a ridge is expected to develop in the Eastern Pacific/Gulf of Alaska. What this means for us is a trough in the Western/Central States, and a ridge in the Eastern United States. To add to this, there has been a fairly dominant area of recurring high pressure in the Caribbean all Winter. Much of the warmth in early December can be linked to this "Caribbean Ridge". The flow around this ridge, will be allowed to "flex its muscle" into the Southeastern United States.
|Image Courtesy of Allan Huffman - RaleighWx|
Here we can see the temperature of the atmostphere a mile up projected for a week from now. Notice the deep "frigid" colors over Northern Canada. Notice how strong they are and how they don't spread too far to the South. Now check out the Southeast, and you can see the ridging I was talking about. What this means is it's gonna be mild for most of next week. I expect some risidual cold to hang on into maybe Monday of next week, then expect a warm up.
This is not a pattern supportive of major snowstorms in the Eastern United States. However, there are some things that tell me this won't be a long term (several week) type warm up.
1) The Polar Vortex is on this side of the continent. There WILL be pieces of cold air that break down and head South for 2-3 days at a time. This alone should throw in some cold snaps in what would be a very mild Mid January pattern.
2) There was/is an ongoing stratospheric warming event. I don't understand the science behind this - - but it strongly correlates to a brutally cold pattern over the Eastern United States about a month after this takes place.
3) Notice on the map above the area of green off the coast of Baja, Mexico. This is indicative of a strong subtropical jet stream. This wasn't present during late fall/early winter. This piece of energy, will eject into the Southern Plains sometime late next week, and likely head north into the Western Great Lakes. Every time a storm system like this happens, it breaks away at the vortex a little more, sending down cold air with it.
Also - - it doesn't take an amazing pattern for snow to happen in this part of the world. Lots of our storms in the past have been the result of right timing in the midst of a mild pattern.
Enjoy the mild air, but don't let your guard down as this weather pattern shows no signs of lasting long term AND still has some shots of cold air.