Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 439 AM EDT Sat Jul 25 2015 Valid 12Z Sat Jul 25 2015 - 12Z Mon Jul 27 2015 ...An upper ridge will ensure hot/dry conditions will continue over the Southern Plains... ...A threat for flash flooding exists across areas of Florida as well as over the Middle Mississippi Valley... ...Much below normal temperatures expected over the northwestern U.S... Across the lower latitudes of the country, a stagnant upper ridge will maintain its stranglehold on the Southern Plains/Lower Mississippi Valley. Strong subsidence underneath this ridge center will ensure abundant heat with readings in the upper 90s to lower 100s without any appreciable threats for rain. Off to the east, a slow-moving upper trough sitting over the state of Florida should keep daily chances for heavy rainfall. A persistent moisture feed intercepting the nearly stalled front combined with slow storm motions supports a threat for flash flooding, particularly in more urbanized settings. With the upper ridge in place across the Southern Plains, a series of disturbances will slide eastward from the Central Plains toward the the Middle Mississippi Valley and Upper Great Lakes region. These features are forecast to be the site for an active period of convection with an inherent risk for flash flooding in some of the more organized thunderstorms. Across the western U.S., a rather pronounced upper trough will dig into the northwestern states bringing a threat for rainfall, especially in areas of terrain where orographic lift will enhance vertical motions. In addition to the precipitation threat, much cooler weather should encompass the region and spread eastward in time. Looking toward Monday, high temperatures should be 15 to 20 degrees below normal across the Central Great Basin and Upper Intermountain West. This generally equates to highs in the upper 50s to 60s which is remarkable for late July. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php