Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 355 AM EDT Sat Jun 13 2015 Valid 12Z Sat Jun 13 2015 - 12Z Mon Jun 15 2015 ...Severe thunderstorms and heavy rain possible from portions of the southern plains to the Northeast... ...Above average temperatures expected to continue for much of the western U.S. and East Coast... Strong high pressure will remain centered over the southeastern U.S. this period. Deep southerly to southwesterly flow along the western periphery of this high will continue to channel very moist and unstable air up from the tropics along a slow moving frontal boundary extending from the Northeast and Great Lakes back into the southern Great Plains. This will fuel widespread showers and thunderstorms from the southern Great Plains northeastward across the mid Mississippi valley, Ohio valley, Northeast and northern Mid-Atlantic states. Some of these storms may become strong to severe. Refer to the Convective Outlook products issued by the Storm Prediction Center for further details on the severe weather threat. In addition to severe weather, heavy rains which may produce localized flash flooding, are possible as well. Refer to the Weather Prediction Center Excessive Rainfall Outlooks for further details on the flash flooding threat. Farther southeast, scattered showers and thunderstorms will affect the central and western Gulf Coast over the next couple days as a very moist and unstable air mass remains in place there as well. A cold front will move eastward across the Rockies tonight and into the northern plains on Saturday, focusing generally scattered showers and thunderstorms. Behind this front daytime temperatures on Sunday are expected to remain as much as 10 to 15 degrees below normal across the northern High Plains. Across the West, high pressure at the mid and upper-levels will extend north from California into the Pacific Northwest, promoting average to above average temperatures through the weekend. Daytime temperatures across much of interior California into northwestern Nevada will climb to 10 to 15 degrees above average on Saturday. On Sunday, these above normal temperatures will extend north into western Washington and Oregon. Above average temperatures will continue as well for portions of the Mid-Atlantic states on Saturday and Sunday, where afternoon high temperatures of 5 to 10 degrees above average are expected. Pereira Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php