Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 419 PM EDT Mon Sep 23 2013 Valid 00Z Tue Sep 24 2013 - 00Z Thu Sep 26 2013 ...Accumulating snows expected in the Northern Rockies... ...Stormy weather in the forecast along the Gulf Coast and Florida... ...Conditions should stay pleasantly dry and quiet across the much of the Ohio Valley...Mid-Atlantic...and New England states... A long wave trough amplifying over the Western U.S. will keep weather unsettled from the Pacific Northwest to the Northern Rockies through the middle of the work week. Widespread showers are expected across the region...and onshore flow...combined with impulses of energy rotating around the upper trough...should allow for some moderate rains to develop...especially along the upslope side of the terrain. Additionally...temperatures will be dropping across the Northwestern U.S. as the trough continues to amplify and eventually closes off an upper low. Conditions should become cold enough to change rain over to snow in some of the higher elevations...with accumulating snows expected along the Northern Rockies. Showers and thunderstorms across the Central Plains and up into the Dakotas should begin to diminish Monday evening as the upper system triggering the precipitation weakens and progresses eastward into the Mississippi Valley. Scattered shower and thunderstorms will continue to focus along a frontal boundary lingering across northern Florida and back into the Western Gulf. Multiple surface waves along the stalled boundary should lead to some organized areas of storms...and given the amount of moisture in place across the region...moderate to heavy rains will be possible. On Tuesday into Wednesday...the system departing the Central U.S. should help lift some of the moisture and precipitation along the Gulf Coast states northward into the Tennessee Valley and Southern Appalachians. To the north of the stormy weather along the Gulf Coast states...a strong surface high set up over the Great Lakes should keep conditions pleasantly dry and quiet across much of the Ohio Valley...Northeast...and Mid-Atlantic states. An exception to this will be across northern New England...where a surface low spinning near the Gulf of St. Lawrence could wrap some light showers down into Maine. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php