Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 457 PM EDT Sat Jun 27 2015 Valid 00Z Sun Jun 28 2015 - 00Z Tue Jun 30 2015 ***Vigorous low pressure system affecting the East Coast*** ***Improving conditions by Sunday for most areas*** ***Heat wave continues for the western U.S.**** A vigorous low pressure system moving across the lower Great Lakes this evening will move northeastward toward the Northeast U.S. today, with the associated cold front moving eastward towards the East Coast by Sunday morning. Widespread showers and thunderstorms are expected to accompany this system, and severe storms are likely from Georgia to the Mid-Atlantic before the front passes. A steady, soaking rain is expected north of the surface low across the Lower Great Lakes and extending eastward over New England by Saturday night. Heavy rain may also result in flash flooding as some areas get multiple rounds of showers and storms. Improving weather is expected for the Mid-Atlantic region and the Ohio Valley on Sunday as drier air moves into the region. In the temperature department, the hot weather is expected to continue for much of the northwestern U.S. A strong upper level ridge will result in increased subsidence and thus hot temperatures. Many areas will likely reach 100 degrees or greater on Sunday and continuing into Monday. Isolated thunderstorms may also develop from northern California to Washington and produce dry lightning and limited rainfall. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php