Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 316 AM EDT Wed May 04 2016 Valid 12Z Wed May 04 2016 - 12Z Fri May 06 2016 ...Severe thunderstorms and heavy rain possible today for portions of South Florida... ...Cool and wet conditions to persist for much of the eastern U.S... ...Above average temperatures expected from the interior Northwest to the northern plains... A low pressure system off the Mid-Atlantic coast and the associated cold front extending south to Florida will bring rain and thunderstorms to much of the East Coast today. Some thunderstorms may be severe across eastern portions of South Florida, where the Storm Prediction Center is forecasting a slight risk of severe thunderstorms. Additionally, heavy rainfall amounts of 1 to 2 inches are possible across much of the central/southern Florida Peninsula. Another low pressure system will quickly cross the Great Lakes today, bringing showers and thunderstorms to the Lower Great Lakes, Ohio valley, and central Appalachians. This system will reach the Mid-Atlantic states Wednesday night into Thursday, with another round of showers and thunderstorms for that region. This area of low pressure is forecast to linger off southern Mid-Atlantic coast into Friday, keeping rain in the picture for much of the Mid-Atlantic. This second low pressure system will also bring cooler temperatures to much of the eastern half of the country, with temperatures 10 to 20 degrees below average for some areas today and Thursday. High pressure aloft will keep above average temperatures in place today from the interior Pacific Northwest to the northern plains, where temperatures will be 15 to 25 degrees above average. These warm temperatures will expand east into portions of the Upper Midwest by Thursday. A slow-moving frontal boundary will gradually move into the western U.S. through the end of the week. The front will bring scattered showers and thunderstorms to much of the central/northern West Coast states today, spreading into the interior West on Thursday and Friday. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php