Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 241 AM EDT Thu May 04 2017 Valid 12Z Thu May 04 2017 - 12Z Sat May 06 2017 ...Showers and thunderstorms with potentially heavy rain expected from the Mississippi valley to the East Coast... ...Temperatures expected to be well above average for much of the western U.S... A low pressure system is expected to deepen as it moves from the lower Mississippi valley to the Ohio valley today, and toward the northeastern U.S. on Friday. Widespread rain and thunderstorms are expected to accompany the system, with heavy rain possible for portions of the Ohio valley, the Southeast, and the southern Mid-Atlantic today through tonight. Friday and Friday night, rain and thunderstorms are expected to overspread much of the Northeastern U.S., with heavy rain possible from coastal portions of the northern Mid-Atlantic to New England. Additionally, the Storm Prediction Center is forecasting a marginal risk of severe thunderstorms associated with this system both today and Friday. Most of the western and central U.S. will see dry conditions today as high pressure remains in place at the surface and aloft. Temperatures are expected to be well above average today from the West Coast to the Rockies and into the northern plains, where high temperatures could reach 10 to 20 degrees above average. The warm temperatures are expected to persist through Friday with the exception of coastal areas of the Pacific Northwest, where a cold front arriving later today will spread showers and a few thunderstorms onshore. The cold front will move into the Great Basin and Intermountain region on Friday, bring showers and thunderstorms to those areas, while cooler temperatures move into the Pacific Northwest, changing rain to snow at the higher elevations of the Cascades. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php