Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 247 AM EST Mon Dec 26 2016 Valid 12Z Mon Dec 26 2016 - 12Z Wed Dec 28 2016 ...Heavy snow and poor travel conditions continue across the Northern Plains... ...Rain and freezing rain possible over parts of the Northern Plains/Upper Midwest... ...Heavy snow for the Cascades and Olympic Peninsula possible through Tuesday... ...Temperatures will be 15 to 25 degrees above average over parts of the Lower Mississippi Valley into the Great Lakes... Widespread snow and strong winds have produced blizzard conditions across much of the Northern Plains since Christmas Day. Nearly every highway has been shut down (or no travel is advised) during the overnight hours across North Dakota and the western half of South Dakota. This winter storm system is forecast to continue on its northeast track, reaching Quebec by Tuesday. Snow will taper off from west to east as the central low pressure lifts out of the Upper Midwest today. Rain and thunderstorms are expected along and ahead of the cold front from eastern Texas, Tennessee/Ohio Valleys and the Northeast today. Portions of New England will have several hours where freezing rain will be possible this afternoon through early Tuesday, before changing over to mostly snow. Much of the Upper Midwest/Great Lakes area have winter weather advisories and winter storm warnings in effect - much of Pennsylvania, new York , Massachusetts and southern Vermont have freezing rain advisories, with winter weather advisories spanning from New Hampshire to Maine. Snow will be possible over portions of the Great Lakes region through Wednesday. The Pacific Northwest will have another round of coastal rain and mountain snow by this afternoon as a low pressure system approaches from the Pacific Ocean. Snow will spread eastward into Interior Washington/Oregon and the Northern Rockies by Tuesday. Winter storm watches are in effect for portions of Washington, Oregon and northern Idaho. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php