Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 454 PM EDT Sun Oct 20 2013 Valid 00Z Mon Oct 21 2013 - 00Z Wed Oct 23 2013 ...The Western U.S. will stay relatively warm and dry while portions of the East will see some of the coolest weather of the season... ...Showers and thunderstorms expected along the Gulf Coast... The amplified pattern over the lower 48 will persist for the remainder of the weekend and well into the work week. An expansive upper ridge anchored off the Pacific Coast will keep locations west of the Continental Divide relatively warm and precipitation free for the next few days...while an upper trough carving out over the Eastern U.S. will bring some of the coolest air of the fall season to locations from the Plains to the Atlantic Coast. Moisture will be rather sparse across much of the East...but multiple pieces of energy rounding the longwave trough...one crossing the Great Lakes and a second streaking southeast out of the Dakotas...will help trigger light to moderate precipitation. Broad...cool...cyclonic flow over warm water should enhance totals downwind of the Great Lakes...and temperatures should be low enough to support snow in some locations. Across the southern tier...a frontal boundary stalled out over Florida and back into the Gulf of Mexico will serve as a focal point for convection during the short range period. Much of the activity should be scattered in nature...but as the tail end of boundary surges northward...some organized areas of heavy rains and thunderstorms could reach the Western and eventually Central Gulf Coast. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php