Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 314 AM EST Mon Jan 15 2024 Valid 12Z Mon Jan 15 2024 - 12Z Wed Jan 17 2024 ...Dangerously cold temperatures continue across much of the U.S... ...Snow and freezing rain continue over the Southern U.S today, spread into the Mid-Atlantic ... ...Heavy lake effect snowfall continues... The main theme to our weather story over much of the Lower 48 remains the brutally cold temperatures and associated significant wintry weather. Little has changed with the "take-home" message regarding the dangerous cold entrenched over the U.S, as sub-zero air temperatures and even colder wind chills prevail through tomorrow before another Arctic blast arrives late this week. This means one more day of frigid wind chills dipping below minus 30 across the Plains states, and minus 50 in Montana and the Dakotas. As we approach mid-week (Wednesday), the initial Arctic airmass will moderate, leading to below average (but still cold) temperatures east of the Continental Divide. Unfortunately, another surge of frigid Arctic air is expected to plunge southward out of Canada later this week, which could lead to more of the same dangerous cold weather across the Midwest and Deep South by the end of the work week. Stay tuned for details as the forecast evolves. In the more immediate term, the frigid airmass in place is also supporting hazardous winter weather across much of the Southern U.S and Great Lakes. Widespread moderate to locally major potential winter storm impacts today are expected across the Lower Mississippi Valley and Tennessee Valley as a mix of snow, sleet, and freezing rain fall before spreading into the Appalachians. Impacts from this storm today may be prolonged even after the wintry precipitation subsides, owing to the Arctic air in place. By later today into tomorrow, snowfall is expected to reach the Appalachians and Mid-Atlantic, including Washington D.C, Philadelphia, and New York. Regardless of how much falls, prepare for slippery road conditions beginning later today into tomorrow. Meanwhile, periods of heavy lake effect snowfall will continue downwind of the Great Lakes through Wednesday, with heavy accumulations focused across northern Michigan, western and Upstate New York including Buffalo. In these areas, moderate to major winter weather impacts can be expected, where localized Winter Storm Watches and Warnings are in effect. Asherman Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php