Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 259 AM EST Tue Feb 16 2021 Valid 12Z Tue Feb 16 2021 - 12Z Thu Feb 18 2021 ...Lingering areas of snow and freezing rain to cause travel concerns from the eastern Great Lakes to New England this morning... ...Frigid Arctic air and dangerously cold wind chills to persist in the Great Plains and Mississippi Valley through midweek... ...A new winter storm emerging in the Southern Plains on Tuesday heads for the Mid-South on Wednesday... The major winter storm responsible for producing significant snow and ice accumulations in parts of the central and eastern U.S. is making a beeline for eastern Canada, but not before it causes heavy snow and freezing rain in parts of the eastern Great Lakes and New England. A couple more inches of snow are possible in the eastern Great Lakes while ice amounts up to a quarter inch are possible. Farther south, the storm's trailing cold front is forecast to trigger showers and thunderstorms over South Florida where Marginal Risks for both severe weather and flash flooding are in place. In the storm's wake, the same area of Arctic high pressure that has enveloped the Heartland in record cold temperatures will spill over towards the East Coast Tuesday evening and into Wednesday. Temperatures will dip to below normal levels on Wednesday but not to the bitterly cold levels that transpired in the Plains and Mississippi Valley in recent days. Speaking of bitter cold, the Arctic high pressure over the Heartland will ensure one more day or frigid temperatures east of the Rockies and west of the Appalachians. Numerous record cold maximum and minimum temperatures are expected today with the bulk of them occurring in the South Central U.S. where daily anomalies range between 35 to 45 degrees below normal. Wind Chill Warnings and Advisories span a massive area from the US/Canada border to the US/Mexico border. Where Wind Chill Warnings are in place, wind chills may plummet to a dangerous 50 degrees below zero at times. The Arctic air-mass begins to modify on Wednesday with fewer record cold temperatures expected but still remain well below normal. Wednesday's low temps are likely to drop below zero from the Midwest to the Lower Great Lakes. An upper level trough tracking through the Four Corners region today is responsible for heavy mountain snow across the Intermountain West. As the trough ejects into the Southern Plains this afternoon, periods of snow will breakout across parts of the Southern Plains with Oklahoma the epicenter for the heaviest accumulations through Tuesday night. Snowfall accumulations over 6 inches are expected there and extending into Arkansas as the upper trough marches east on Wednesday. The same upper trough will help to create a new wave of low pressure in the Gulf of Mexico that becomes the next winter storm to track across the Lower Mississippi Valley and into the Ohio and Tennessee Valleys. Snowfall accumulations on Wednesday appear to be on the order of 3 to 6 inches in these areas, while significant ice accumulations take shapes from east Texas to the Mississippi Delta region. Ice accumulations ranging between a quarter to a half inch are possible which would make for hazardous travel conditions, induce more power outages, and cause more tree damage in these areas. Eventually, this storm system will head for the Mid-Atlantic by Thursday where accumulating snow and ice will likely lead to more treacherous travel conditions. Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php