Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 251 PM EST Tue Dec 05 2017 Valid 00Z Wed Dec 06 2017 - 00Z Fri Dec 08 2017 ...Arctic airmass to settle into the Eastern and Southern states with temperatures as much as 20 to 30 degrees below normal across the southern Plains... ...Locally heavy lake effect snow likely downwind of the Great Lakes... ...Snow possible over parts of Southwestern Texas with widespread rainfall from the southern Plains to the Southeast... Moderate to locally heavy rainfall along a strong cold front will push through the Northeast and Mid-Atlantic this evening and overnight coming to an end by Wednesday as the front pushes offshore. The southern portion of the front may be slower to move which should keep widespread showers and thunderstorms lingering across the Gulf Coast states, the Southeast, and Florida over the next few days. Behind the front, the seasonably warm temperatures across the east will quickly come to an end as an arctic air mass settles in. Most places east of the Rockies will be below normal the next few days, especially for much of the southern Plains and Lower Mississippi Valley where afternoon highs could be as much as 15 to 30 degrees below normal. As the deep surface low associated with this system lifts farther into Canada, cold air moving over the still relatively warm lakes will allow for some moderate to locally heavy lake effect snowfall downwind of the Great Lakes the next few days. Winter storm warnings, advisories, and lake effect snow warnings are in effect downwind of Lakes Superior, Erie, and Ontario where as much as a foot or more of snow could fall. Elsewhere, upper level energy moving through aloft combined with the cold temperatures will bring the possibility for accumulating snow or a rain/snow mix to portions of southwest Texas on Wednesday and Thursday. Winter storm watches are in effect for parts of Southwest Texas where 2 to 6 inches of snow are forecast. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php