Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 324 AM EDT Sat Sep 19 2015 Valid 12Z Sat Sep 19 2015 - 12Z Mon Sep 21 2015 ...Showers and thunderstorms expected today and tonight for portions of the Great Lakes, Ohio valley, and the Northeast... ...Cooler temperatures will reach the Northeast by Sunday... ...Cold front to reach the Pacific Northwest on Sunday, bringing a chance of showers to coastal areas... A deepening low pressure system will from the Great Lakes this morning to Quebec by this evening. The trailing cold front will bring scattered to numerous showers and thunderstorms to portions of the Great Lakes and Ohio valley today, spreading into the Northeast by this evening. By Sunday morning, the cold front ill be moving offshore, with only a few lingering showers early for coastal New England. While temperatures will be 10 to 15 degrees above average today across the Northeast, the cold front will bring a return to near or below average temperatures by Sunday. This cooler air mass will be across the central plains and Midwest today, with high temperatures expected to be 5 to 10 degrees below average. Scattered showers and thunderstorms are also possible along the tail end of the cold front across the southern plains. This front will become stationary tonight, before beginning to move northward as a warm front on Sunday, keeping scattered showers and thunderstorms a possibility across the southern plains through the weekend. A weak wave of low pressure will also develop along the front across the southeastern U.S. late on Sunday, with the potential for scattered showers and thunderstorms into Monday. A cold front will reach the Pacific Northwest on Sunday, bringing showers primarily to coastal portions of Washington State as well as the Cascades. Areas farther inland will remain dry, and the front will bring cooler temperatures as well as windy conditions. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php