Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 345 AM EDT Tue Sep 17 2013 Valid 12Z Tue Sep 17 2013 - 12Z Thu Sep 19 2013 ...Unsettled weather is expected from the Pacific Northwest to the northern Plains... ...Showers and thunderstorms will continue across South Texas... ...Dry and cool conditions expected across much of the eastern U.S.... Unsettled weather is in the forecast for the northwestern corner of the U.S. over the next few days as an upper trough over the northeastern Pacific slides inland. Onshore flow in the wake of its associated cold front is expected to encourage scattered showers across the Pacific Northwest into the northern Rockies today . By Wednesday as the upper trough continues to progress eastward through the northern Rockies, a strong surface low is expected to intensify over northern Plains with better organized precipitation expected to develop across northern MT into ND. Further east, an upper disturbance breaking away from the trough over the western U.S. is expected to encourage showers and thunderstorms from the central Plains into the Great Lakes and OH valley. To the south, even with Ingrid currently dissipating across the mountainous terrain of eastern Mexico, plenty of moisture is forecast to remain across Deep South TX and along the Rio Grande valley, fueling scattered showers and thunderstorms across the region over the next couple of days. Across the eastern U.S., frost advisories and freeze warnings have been hoisted across a large portion of the Northeast and upper Great Lakes regions as a cold front continues to settle south into the southeastern U.S. with an area of strong high pressure drifting southeast from the Great Lakes into the Northeast and mid Atlantic states. While seasonal to below average temperates are expected to persist across the Northeast into the mid Atlantic region over the next couple of days, southerly winds on the backside of the high will bring a return to warmer weather across the Midwest by Wednesday. While much of the East is expected to remain dry, showers and thunderstorms are expected both days across FL. Pereira Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php