Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 320 PM EDT Fri May 26 2017 Valid 00Z Sat May 27 2017 - 00Z Mon May 29 2017 ...Severe thunderstorms and locally heavy rain possible from portions of the plains to the Mid-Atlantic through the weekend... ...Warming temperatures expected for the Pacific Northwest through the weekend... An area of low pressure drifting eastward across the Ohio Valley tonight and into the Mid-Atlantic on Saturday will keep conditions unsettled with showers and thunderstorms developing along the associated frontal boundaries. Meanwhile, a second area of low pressure will continue to bring showers and higher elevation snows to portions of the central Rockies and high Plains tonight. The low will strengthen as it moves eastward this weekend across the Plains and into the Upper Midwest dragging a cold front southward across the central and southern Plains, and the middle Mississippi Valley. Expect numerous showers and thunderstorms to develop along the cold front from the Plains to the Ohio Valley Saturday evening, dropping south and eastward towards the Gulf Coast and the Mid-Atlantic by Sunday. Some of the storms may bring heavy rainfall, severe weather, and flash flooding. The Storm Prediction Center has highlighted a large area from the southern Plains to the southern Mid-Atlantic in a slight to moderate risk for severe weather on Saturday and Sunday, while WPC is forecasting a marginal to slight risk for flash flooding in roughly the same area. Please refer to the excessive rainfall graphics from WPC, and severe thunderstorm outlooks from SPC for additional information. Behind this system across the Western U.S., an upper-level ridge will dominate, keeping the Western states mostly dry, with the exception of some light rains along the favored terrain of the Rockies. Temperatures will be on the rise though, with daytime highs in the 80s and 90s, which is as much as 10 to 20 degrees above average. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php