Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 426 AM EDT Wed Sep 18 2013 Valid 12Z Wed Sep 18 2013 - 12Z Fri Sep 20 2013 ...Strong to severe thunderstorms possible from the northern Plains to the upper Midwest and lower MO valley... ...Unsettled weather continuing along the Gulf Coast into South TX... ...Moderating temperatures across the Northeast... A strong surface low is forecast to develop today over the northern Plains as a well-defined upper trough moves across the northern Rockies. Showers and thunderstorms are expected today from the northern Rockies into the Plains. Some of these storms may turn severe, particularly across the northern Plains later today where the Storm Prediction Center has indicated a slight risk for severe weather. A strong trailing cold front is forecast to become more active with showers and thunderstorms as vigorous southerly winds ahead of the boundary usher in deep moisture originating from the tropics. Some of these storms may become severe as the front pushes southeastward through the upper Midwest, lower MO valley and the south-central Plains on Thu, as indicated by the slight risk for severe weather in the Storm Prediction Center's Day 2 Outlook. Further to the south, unsettled weather is expected to continue from the FL peninsula to South TX as a moist and unstable airmass remains in place, fueling showers and thunderstorms both days. After another chilly morning across the Northeast, highlighted by frost advisories and freeze warnings across parts of the area, temperatures will begin to moderate as high pressure centered over the region drops further to the south, allowing southwesterly winds to usher in warmer temperatures. Pereira Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php