Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 254 PM EDT Sat May 11 2019 Valid 00Z Sun May 12 2019 - 00Z Tue May 14 2019 ...Heavy rain and severe thunderstorms possible from the Gulf Coast to the Mid-Atlantic through Sunday... ...Heavy to excessive rainfall possible across parts of the Southern High Plains Sunday into Monday... ...Temperatures from the Midwest to the Northeast and back to the Southwest will be below normal, while much above normal temperatures across the Northwest will expand eastward this weekend... A slow moving frontal boundary in the Eastern U.S. will continue to provide support for showers and thunderstorms from the Gulf Coast/Southeast into the Mid-Atlantic tonight and through Sunday. The best chance for flash flooding tonight will be across the central Gulf Coast where previous days of very heavy rainfall have left this region particularly susceptible to any additional rains. The flash flood threat will extend northward into the Mid-Atlantic as well through Sunday, coming to an end across the Gulf Coast as the front shifts eastward. Strong to severe thunderstorms are also possible, especially across parts of the Gulf Coast tonight, and into the Southeast/Southern Mid-Atlantic tomorrow. Refer to the outlooks provided by WPC and SPC for additional information on the flash flood and severe weather threats. By Monday, a surface low should begin to consolidate and lift north off the Mid-Atlantic coast spreading rain, heavy at times, into the Northeast. Elsewhere, mainly light and scattered rain is possible associated with a secondary frontal boundary moving from the Mississippi Valley into the Ohio Valley tonight and into Sunday. Another upper level system moving from the Southwest to the southern High Plains will allow for showers and storms across these regions. Locally heavy rainfall is possible, and WPC has highlighted parts of the Southern Plains within a slight risk for excessive rains/flash flooding Sunday and Monday. Temperatures across the CONUS for the short range period will feature well below normal temperatures from the Midwest to the Mid-Atlantic and the Northeast where daytime highs could be 10 to 20+ degrees below average for this time of the year. Near to below normal temperatures will also extend into parts of the Southwest as the second upper level system moves in by the end of the weekend. The much above normal temperatures across the Northwest will expand eastward through the weekend into the northern/central Rockies and eventually parts of the northern Plains by Monday. Temperatures across these regions could be 10 to 20 degrees above normal. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php