Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 455 AM EDT Sat Jun 29 2013 Valid 12Z Sat Jun 29 2013 - 12Z Mon Jul 01 2013 ...Scorching heat will continue across the Western U.S.... ...A stormy weekend is in store for the Eastern Seaboard... Scorching heat will continue underneath an expansive upper ridge parked over the Western U.S. this weekend. Temperatures will yet again approach or exceed records on Saturday and Sunday across much of the Southwest and Great Basin. Staring late this weekend and into early next week...the upper ridge will begin building northward and triple digit temperatures will spread north all the way to the Canadian border. Heat advisories have already been posted for portions of Washington...Idaho...and western Montana. The strong ridge in place will inhibit precipitation across the majority of the Western U.S....however...a bit of moisture combined with upslope flow should help trigger some late afternoon thunderstorms over the Central to Southern Rockies. Downstream from the sizzling temperatures in the west...an upper trough will continue to amplify over the Eastern half of the country while the associated surface front stalls out near the Appalachians. Muggy and stormy conditions will persist south and east of the boundary...across Florida and all along the Eastern Seaboard. The widespread threat for severe weather has diminished...but developing storms will still have the possibility to produce heavy rains...strong winds...or even some hail. Behind the stalled frontal boundary...shortwave energy diving southeastward within the amplifying trough will help produce some scattered showers and thunderstorms across the Upper Mississippi and Ohio Valleys this weekend. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php