Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 450 AM EDT Fri Jun 28 2013 Valid 12Z Fri Jun 28 2013 - 12Z Sun Jun 30 2013 ...Significant heat wave expected for much of the Western U.S.... ...Flash flooding possible across New England on Friday... ...Stormy weather is in store for the Eastern U.S.... Record breaking heat will continue underneath an expansive upper ridge building in over the Western U.S.. Excessive heat watches and warnings have been posted across much of California...Nevada...and Arizona...where daytime temperatures will soar well into triple digits and overnight lows will struggle to drop into the seventies and eighties. A few isolated thunderstorms...containing minimal precipitation...will be possible along the higher elevations of the Rockies and Great Basin. Instead of providing relief from the heat this weekend...these dry storms will only enhance the fire weather threat across a very hot and dry region. While the Western U.S. gets scorched underneath a building ridge...an upper trough amplifying downstream will bring cooler and stormy weather to the eastern half of the nation this weekend. Numerous showers and thunderstorms will continue to break out ahead of the associated surface front slowly edging eastward out of the Midwest and towards the Atlantic coast. An abundance of moisture and instability available ahead of the boundary will allow for some of the developing storms to become organized and capable of producing severe weather. For the latest information on severe weather...please refer to the Storm Prediction Center. A strong surface low along the front will track through the Northeast on Friday...bringing steady rains with embedded thunderstorms into New England. Plenty of Atlantic moisture getting pulled inland across the region could lead to some heavy downpours and flash flooding. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php