Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 403 AM EDT Mon Oct 21 2013 Valid 12Z Mon Oct 21 2013 - 12Z Wed Oct 23 2013 ***Ridging in the West and trough in the East continues*** ***Unseasonably cool from the Great Lakes to the East Coast*** ***Scattered showers and storms for the Gulf Coast*** With an amplified upper air pattern over the continental United States, a large scale ridge is expected over the Inter-Mountain West and West Coast, and a trough over the Eastern U.S. This will generally equate to relatively warm and dry weather west of the Rocky Mountains, and the coolest weather of the fall season for the Midwest states to the East Coast. Periods of cold showers are expected for locations near the Great Lakes during the next few days, and this could become mixed with snow at times, especially during the overnight hours. Widespread frost and freeze conditions are likely by the middle of the week as lows reach the upper 20s to upper 30s from the Midwest to the Mid-Atlantic region. Across the southern tier, a frontal boundary stalled out over Florida and back into the Gulf of Mexico will serve as a focusing mechanism for showers and thunderstorms during the short range period. Much of this activity should be scattered, but as the tail end of boundary lifts northward, some organized areas of moderate to heavy rain and embedded thunderstorms could reach the Western and Central Gulf Coast. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php