Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 353 AM EDT Fri Aug 16 2019 Valid 12Z Fri Aug 16 2019 - 12Z Sun Aug 18 2019 ...Severe weather and flash flooding expected for the Northern/Central Plains to Upper/Middle Mississippi Valley... ...Heavy rain remains possible for the Florida Big Bend... ...Heat continues for the southern tier with excessive heat in the Southwest and California... A slow-moving frontal boundary will provide a focus for rain and thunderstorms on Friday and Saturday for the center of the country. An Enhanced Risk of severe weather is forecast by the Storm Prediction Center for the Central Plains and Middle Mississippi Valley today, and a Slight Risk of excessive rainfall/flash flooding is in place for those regions as well. The chances for thunderstorms spread a bit northward on Saturday ahead of a cold front making its way through the Northern Plains toward the Upper Midwest. Slight Risks of both severe weather and flash flooding are currently forecast on Saturday for portions of the Central/Northern Plains and the Middle Mississippi Valley to Upper Midwest. A stationary front is expected to remain over the Carolinas and the Southeast over the next couple of days, and showers and thunderstorms will persist along it. With Gulf moisture flowing into the vicinity of the front, locally heavy rainfall rates are possible as well as storms repeating over the same areas--areas that have seen abundant rainfall recently. Thus, Slight Risks of flash flooding have been outlooked for the Big Bend of Florida and into southern Georgia for Friday and Saturday. Temperatures will remain hot for the southern half of the U.S. through the end of the week. Excessive Heat Warnings and Heat Advisories are in place on Friday across the valleys of California and for the Southwest, as temperatures over 100 degrees are expected for these areas and into the Southern High Plains. By Saturday, above average high temperatures will spread into the Ohio Valley and Mid-Atlantic, while California is expected to cool down. Additionally, the cold front that is forecast to move south into the Northern High Plains by Saturday should drop high temperatures to 15 to 25 degrees below average. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php