Heavy rain across much of the country and the potential for a tornado outbreak in parts of the south will make for a crappy start to next week, followed shortly thereafter by a blast of cold air that could be the final gasp of the winter that won't die.
A strong cold front will serve as the focus for heavy rain and thunderstorms on Sunday across the east-central Midwest up through the Great Lakes region, producing over three inches of rain in some spots (the rainfall forecast map is seen above). The potential for some accumulating snow can't be ruled out, especially across parts of Wisconsin and Michigan.
A period of heavy thunderstorms will produce a general area of two to three inches of rain across the Deep South, with the heaviest rain totals along the coast from New Orleans to Pensacola.
There is an increasing risk for a severe weather outbreak across parts of Oklahoma, Texas, Arkansas, and Louisiana on Sunday that could include the risk for tornadoes, damaging winds, and large hail.
The image above shows the Energy Helicity Index (EHI) from last night's run of the NAM (North American Model). The EHI takes into account both the CAPE — essentially the fuel that feeds thunderstorms — and the potential for rotation in the atmosphere.
Higher EHI values indicate higher risk for strong thunderstorms that could rotate, meaning that there is a higher potential for supercells capable of producing tornadoes, very large hail, and damaging winds.
While the above map probably shows EHI values higher than what will occur, it signals that there is a very real chance for a severe weather outbreak across the south-central United States on Sunday.
Behind the cold front, cold temperatures will flow southward into much of the eastern two-thirds of the United States, with low temperatures possibly reaching the 30s as far south as northern Georgia.
It's going to be an interesting period for weather — and a potentially dangerous one — so if you live in any of the areas at risk for severe weather on Sunday or Monday, keep an eye on your local forecast this weekend and make plans for what to do if dangerous storms threaten.