Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 356 AM EDT Mon Apr 02 2018 Valid 12Z Mon Apr 02 2018 - 12Z Wed Apr 04 2018 ...Early springtime snow expected from the Mid-Atlantic to New England on Monday... ...Heavy snow expected for portions of the Upper Midwest and Great Lakes... ...Severe thunderstorms possible for parts of the Tennessee and Ohio Valleys on Tuesday... Early springtime snowfall is expected this morning across the Mid-Atlantic and Northeast before pushing into New England by this afternoon. The upper level disturbance associated with this system will push out into the Atlantic by this evening. All precipitation will come to an end by tonight. Winter weather advisories are in effect for the northern and western portions of the Mid-Atlantic northward into southern New England. Meanwhile, a robust upper level low moving over the Pacific Northwest will slide across the Intermountain West today. These regions can expect an increase of rain with higher elevation snow throughout the day. By Tuesday, this upper level system will slide eastward over the Plains. With an Arctic airmass in place, precipitation in the form of snow will move into the northern High Plains and northern Plains by this afternoon while snow continues along the northern and central Rockies. On Tuesday, as the upper level system shifts toward the Mississippi Valley, a surface low will develop and strengthen while lifting north toward the Great Lakes throughout the day as snow north of the low will spread from the northern Plains to the Upper Midwest. By Tuesday evening, heavy snow will occur along the Upper Great Lakes--with over a foot of snow expected in northern Michigan. The heavy snow will move north into Canada by early Wednesday morning; however, some lingering lake effect snow is expected over parts of both the upper and lower Great lakes. Please see WPC's winter weather products for more information. Areas along the Tennessee Valley can expect lingering showers and thunderstorms today as a frontal boundary draped over the area will provide focus for convection. As the surface low associated with the heavy snow in the Great Lakes moves north and east, it will cause the frontal boundary across the Tennessee Valley to lift north as a warm front. At the same time, a strong cold front will advance from the middle Mississippi Valley into the Ohio and Tennessee Valleys during the day. Deep southerly flow will bring copious amounts of moisture ahead of the front while instability increases--causing convection to fire along the boundary. Some of these thunderstorms could become severe especially for western portions of the Ohio and Tennessee Valleys during Tuesday afternoon and evening. As such, The Storm Prediction Center has an enhanced risk of severe thunderstorms for this area. Please see SPC products for further information regarding this system (www.spc.noaa.gov). The line of thunderstorms will stretch into southeast Texas on Tuesday and move eastward with the cold front. By Wednesday morning, precipitation will extend from New England to the western Gulf Coast. Reinhart Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php