Short term quiet with the January Thaw coming as promised since December 30th, (70 not out of the question), Old Man Winter will return to the US, starting in the West. Some short to medium range highlights:

A) A flooding rain and strong thunderstorm event for Texas and
Louisiana on Tuesday and Wednesday but weakens beyond Alabama.

B) A surge of bitter cold Arctic air and a prominent winter storm
moving from Texas into Quebec (Midwest impacts for snow and ice,
severe thunderstorm and heavy rain across the Old South next week)

C) The southward descent of the motherlode of Arctic air into Ontario
and Quebec during the 11-15 day forecast period. Winter storm risks
for The Old South, Appalachia and the eastern Seaboard and much of the
nation dealing with much below normal temperatures that may last
through the end of the month. The CFS suggests a very cold
February as well.

A rather challenging weather pattern to be sure. But winter will be
heard from in much of the country, and soon. SE will be last as upper ridge resists.

A SSW event in the near-outter space environment (stratosphere) sudden stratospheric warming above the North Pole splits the polar vortex forcing arctic air below southward, in the past this usually happens 10-20 days later and generally last 3-6 weeks.

Energy digging southward in the formative western/central U.S. trough should initiate cyclogenesis along the western Gulf Coast around January 13, with the deepening surface low pressure center likely moving into the Ohio Valley and lower Great Lakes.

This may be an important snow and ice maker for parts of the Midwest (I  think that North of a line from Wichita KS, St. Louis MO, Chicago IL, and Grand Rapids MI may be in the line of fire from winter weather), and there is potential for a center redevelopment off  the VA Capes. The concern obviously is the impressive -NAO signal/Greenland block setting up in this time frame which in theory would dictate a shift of colder air and the storm track more to the south and east with time. Severe weather and heavy rainfall threats must also be mentioned for much of the Old South, what with the strong upper winds, thermal boundary and rapidly ejecting 500MB vorticity maximum from the lower Great Plains.

A variety of miserable and ugly conditions are likely between the Continental Divide and Atlantic Coastline before January 20th give or take. Then pretty much everyone outside of the West Coast will be staring true "January weather" in the face.

In the 6 - 10 day period, the EURO model has a fairly impressive Greenland (-NAO) block taking shape which would seem to favor a stronger surface storm with potential for redevelopment off of the Virginia Capes around January 14. I like the ECMWF idea of holding on to warmth in the Southeast (note the high 500MB heights in Cuba and the Bahamas). When new southern branch storm energy enters the picture form northern Mexico, real trouble will be brewing.

I can foresee the potential for cyclogenesis near South TX, with a slow deepening storm moving into GA, then turning northward very close to the Atlantic shoreline from the Carolinas into ME and NS. The timing on this matter is up for grabs, but January 17 - 22 or so is a decent estimate for now. Because of the vivid -NAO signal on the ECMWF and GGEM ensemble packages (remember that a concurrent -EPO ridge complex looks to be in place over or near Alaska), the potential exists for the incoming disturbance to interact or possibly phase with the cAk motherlode. Besides making most of the U.S. very cold, such a scenario implies very strong winds and heavy precipitation across the Old South, Appalachia, and the Eastern Seaboard (to say nothing of snow squalls over the Great Lakes, which could be plentiful with so much cold air and energy across open waters). While there is a fair chance that the Interstate 20 and 95 corridors could see mainly rain in such a situation, snow and ice will not be far away IF what the computer models and teleconnection charts are telling us is true.

LONG AND SHORT:  Jan starts cold turns warm mostly benign, but ending weeks exciting and window for GA winter may stay open through February 18th ish with heavy rain and/or severe threat in the transition.