Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 411 PM EDT Tue Oct 31 2017 Valid 00Z Wed Nov 01 2017 - 00Z Fri Nov 03 2017 ...Heavy rainfall possible for portions of the southern Plains and central Gulf Coast tonight and into Wednesday... ...Accumulating snowfall possible from the northern Plains to the Upper Mississippi Valley... ...Heavy mountain snowfall likely across parts of the Pacific Northwest and northern Rockies... Lingering moisture along a weakening frontal boundary will keep showers and thunderstorms in the forecast from the southern Plains northward through the Ohio Valley and into the lower Great Lakes the next couple of days. Heavy rainfall will be likely across portions of the Southern Plains and central Gulf Coast this evening and into tomorrow, with isolated flash flooding and severe thunderstorms possible. On the north side of the front, another day of cool temperatures from the Ohio Valley to the Northeast is in the forecast on Wednesday, with some precipitation mixing with or changing to snow during the overnight hours possible. By Thursday, expect a sharp warm up with temperatures close to 10 degrees above normal ahead of a second system approaching from the west. Multiple waves of energy moving through aloft over the Northern Tier states will help push a cold front through the northern Rockies, northern and central Plains, and the Upper Midwest the next few days. Daytime rain and overnight accumulating snowfall will be possible, especially across the northern Plains and the upper Mississippi Valley. Generally, 2 to 4 inches of snow is forecast across these areas with winter storm warnings also in effect for portions of northern Minnesota. Farther to the west, heavy mountain snows are possible with upwards of a foot possible in the highest terrain of the northern Rockies. Behind the front, temperatures will be chilly with afternoon highs around 10 degrees below normal. Out west, a strong upper level system dropping down along the western Canadian coast will return precipitation to much of the Pacific Northwest starting by Wednesday afternoon. Expect heavy snowfall in the mountain, particularly the Washington Cascades, with amounts near or exceeding a foot over the next several days. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php