Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 420 PM EDT Mon Sep 16 2013 Valid 00Z Tue Sep 17 2013 - 00Z Thu Sep 19 2013 ...Unsettled weather is expected from the Pacific Northwest to the Northern Plains... ...Showers and thunderstorms will continue across South Texas... ...Weather should stay pleasantly dry and quiet across much of the Eastern U.S.... Unsettled weather is in the forecast for the northwestern corner of the Nation the next few days as an upper trough off the Pacific Coast slides inland. Not much precipitation is expected along the associated cold front dropping through the region...but behind the boundary...enough onshore flow combined with favored orographics should allow for widespread light to moderate shower activity from the Pacific Northwest to the Northern Rockies. By Wednesday..the upper trough will progress eastward across the Northern High Plains...and a surface low intensifying in the lee of the Rockies could lead to more significant precipitation over portions of Montana. Across the middle of the Country...showers and thunderstorms will continue to break out from the Southern Rockies to the Central Plains Monday evening into Tuesday. A piece of energy streaking through aloft could help precipitation to become more organized...and as the energy lifts northeastward on Wednesday...showers and thunderstorms will become a possibility across the Midwest. To the south...a rich supply of moisture should continue to fuel moderate to heavy rains over South Texas. Conditions will continue to clear out across the eastern U.S. as a cold front pushes farther out into the Atlantic. Strong high pressure building in behind the front should keep weather pleasantly dry and quiet through the middle of the week...however...the clear skies overnight will lead to some brisk mornings. Frost advisories and freeze warnings have been posted across portions of the Great Lakes and New England. An exception to the dry and quiet weather in the East will be across Florida...where additional days of showers and thunderstorms are expected for much of the Sunshine State. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php