Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 331 AM EST Mon Mar 06 2017 Valid 12Z Mon Mar 06 2017 - 12Z Wed Mar 08 2017 ...Heavy snow will continue today across portions of the Pacific Northwest, California, and the Intermountain West... ...Widespread showers and thunderstorms are possible for much of the eastern U.S. over the next couple of days... ...A wintry mix will transition to all snow today across the Northern Plains... Continued onshore flow across the Pacific Northwest will promote more rain along the Pacific coast today, and snow showers inland well into the Intermountain West. These will slowly taper off throughout the day and overnight. Winter Storm Warnings and Winter Weather Advisories remain in effect for portions of the northwest U.S. through today for continued snow concerns. Meanwhile, a low pressure system continues to gain considerable strength as it moves into the Northern Plains this morning. This system will shift northeast into the Upper Mississippi Valley this evening, reaching South Central Canada overnight. An extensive cold front associated with this low will push eastward across much of the central U.S. throughout the day, then across the Mississippi Valley and Southern Plains tonight. It will then proceed to the Atlantic Seaboard by Wednesday morning. Strong return flow along the back side of a departing high is currently allowing warm and moist air to stream northward from the Gulf of Mexico. This will continue to spark scattered showers and thunderstorms across much of the southeast U.S. throughout the day. However, as the cold front approaches the Mississippi River later in the day, this warm, moist, and unstable flow will be further enhanced, resulting in stronger and more widespread showers and thunderstorms for much of the Mississippi River Valley region this evening, and points eastward overnight and into Tuesday. The Storm Prediction Center has outlined a portion of the Lower to Middle Mississippi Valley region in an enhanced risk of severe thunderstorms from late this afternoon into the overnight, and much of the Central and Southern Plains northward into the Middle and Upper Mississippi Valley in a slight risk during this time. Please refer to the SPC website for more information. Concurrently, much of the northern plains will find themselves on the back side of the low and in the cold sector. Precipitation here will continue to fall as a wintry mix of rain, snow, and sleet through this morning, transitioning to all snow today as colder air pushes southward from Canada throughout the day. Winter Weather Advisories are currently in effect for portions of the Northern Plains as a result. Wix Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php