Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 229 AM EDT Wed May 03 2017 Valid 12Z Wed May 03 2017 - 12Z Fri May 05 2017 ...Severe thunderstorms and flash flooding possible across portions of the lower and mid Mississippi valley... ...Warming temperatures expected for much of the western U.S... A low pressure system is expected to rapidly take shape across the southern plains and lower Mississippi valley today. The system will bring numerous showers and thunderstorms to areas from the western Gulf Coast and southern plains to the mid-Mississippi and Ohio valleys through tonight. Abundant moisture streaming northward into the system will support the potential for heavy rainfall, and flash flooding will be possible, with the greatest flash flooding threat expected across the mid-Mississippi valley. Additionally, the Storm Prediction Center is forecasting a slight to enhanced risk of severe thunderstorms across much of the western Gulf Coast and lower Mississippi valley through tonight. Please refer to products issued by the SPC for further details on the severe weather threat. On Thursday, the surface low will move into the Ohio valley, with widespread showers and thunderstorms expected ahead of the system from the Southeast to the Mid-Atlantic. Rain and a few thunderstorms associated with the system will reach New England Thursday night into Friday. High pressure will dominate the weather pattern across the western U.S. through the short range forecast period, with generally dry conditions expected to prevail into early Thursday. Above average temperatures are also expected, with high temperatures reaching 10 to 20 degrees above average for many areas. By Thursday afternoon, a Pacific frontal boundary will approach the West Coast, spreading showers and a few thunderstorms into the Northwest through Friday morning. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php