Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 250 PM EDT Mon Apr 18 2016 Valid 00Z Tue Apr 19 2016 - 00Z Thu Apr 21 2016 ...Flash flooding possible for portions of the southern plains and western Gulf Coast through tonight... ...Severe thunderstorms possible for portions of South Texas... ...Well above average temperatures expected for the northwestern U.S... A cutoff upper-level low across the central Rockies along with a stationary surface front extending from the southern plains to the Midwest will continue to bring scattered to numerous showers and thunderstorms to much of the central U.S. through the next couple days. Heavy rainfall will be possible for areas that have already received excessive rainfall -- thus, flash flooding will remain possible across portions of the southern plains and western Gulf Coast region through tonight. Additionally, the Storm Prediction Center is forecasting a slight risk of severe thunderstorms through tonight across portions of South Texas. On Tuesday, the threat of flash flooding will expand a little farther north into the Mid-Mississippi valley. Farther west, scattered snow showers will continue across the Rockies through Tuesday before tapering off. The upper-level low and stationary front will move little through Tuesday, with showers and thunderstorms continuing for many of the same areas. The system is finally forecast to begin a slow movement eastward by Wednesday afternoon and evening, when showers and thunderstorms will begin to spread into portions of the Ohio and Tennessee valleys. High pressure will keep the Northeast and Mid-Atlantic dry through Wednesday, with temperatures generally near or above average. The western U.S. will also remain largely dry through the next couple days -- although a few showers or thunderstorms will be possible across the Pacific Northwest Tuesday and Wednesday. Temperatures will be warm across the Northwest -- where afternoon highs are forecast to be 15 to 25 degrees above average Tuesday and Wednesday, with many areas rising into the 80s. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php