Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 458 PM EDT Sat Jul 25 2015 Valid 00Z Sun Jul 26 2015 - 00Z Tue Jul 28 2015 ***Hot and humid across much of the southern U.S.*** ***Showers and storms from the northern Plains to the Ohio Valley*** ***Turning cooler for the northwestern U.S.*** The southern Plains and the Deep south states will continue to endure relentless heat and humidity through Monday as a stubborn upper level ridge remains parked over that region. Subsidence and mostly sunny skies will allow for widespread 90s and lower 100s for daytime highs and mid to upper 70s for overnight lows. The high dewpoints combined with the heat is expected to result in 100+ degree heat indices, with heat advisories and excessive heat warnings in effect. With the upper ridge in place across the central U.S., a series of disturbances will move eastward from the central Plains toward the Ohio Valley and Great Lakes. These features are expected to produced multiple organized thunderstorm complexes along with a localized risk for flash flooding from some of the more organized thunderstorms. Widespread thunderstorm activity is also likely for Florida as a stalled frontal boundary remains over the region. For the western part of the nation, an amplifying upper trough will dig into the northwestern states along with a cold frontal passage. Scattered showers and storms are expected to develop in the vicinity of this boundary, with the greatest rainfall for the elevated terrain. A refreshing, high quality airmass will settle in for the Pacific Northwest and northern Intermountain West by the end of the weekend, with crisp mornings and pleasant afternoons. D. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php