Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 239 AM EST Sun Dec 11 2016 Valid 12Z Sun Dec 11 2016 - 12Z Tue Dec 13 2016 ...Heavy snow possible from portions of the northern plains and Midwest to the Northeast... ...Heavy snow possible for the Cascades and portions of the Rockies and Intermountain West... ...Another round of cold air expected to move into the northern plains and Upper Midwest... A low pressure system over the central U.S. this morning will spread snow across areas from the northern plains to the Northeast today and tonight. Heavy snow is possible for some areas. Farther south, a mix of wintry precipitation including snow, sleet, freezing rain, and rain is possible from portions of the Ohio valley east into the Mid-Atlantic region today and tonight. Meanwhile, rain and a few thunderstorms are possible ahead of the cold front from the lower Mississippi valley to the southern Appalachians. On Monday, snow, sleet, and freezing rain will continue across the Northeast during the morning, with rain farther south from the Mid-Atlantic to the Southeast. The frontal system will move quickly east during the day, with precipitation across the eastern U.S. becoming much more scattered by Monday afternoon and evening. The front is expected to linger from the lower Mississippi valley to the Southeast on Tuesday, keeping scattered showers and storms a possibility. A couple lingering frontal boundaries, and a series of upper-level disturbances will keep the western U.S. unsettled through the short range. Heavy snow is possible today and tonight across the Cascades as well as across the higher elevations of the Intermountain West and Rockies. The region will see somewhat of a lull in precipitation during the day on Monday, although scattered areas of snow will remain, with rain showers along the coast. Monday night in to Tuesday another Pacific storm system will approach the coast, spreading rain and mountain snow into central and northern California and southern Oregon. Colder air will gradually move into the northern plains over the next couple days as an area of arctic high pressure noses southward east of the Rockies. Afternoon high temperatures across the northern plains today and Monday are forecast to be 20 to 30 degrees below average. On Tuesday the colder temperatures will spread east into the Upper Midwest as well, with high temperatures expected to be 15 to 25 degrees below average. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php