Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 343 AM EDT Tue Apr 19 2016 Valid 12Z Tue Apr 19 2016 - 12Z Thu Apr 21 2016 ...Flash flooding possible for portions of the southern plains and Middle Mississippi Valley today... ...Well above average temperatures expected for the northwestern U.S... A cutoff upper-level low with an associated quasi-stationary front from the Midwest to the southern plains will continue to generate numerous showers and thunderstorms over the next couple of days. Excessive rainfall has already caused significant flooding issues in Texas - the threat will slowly decrease through the day as the area of higher precipitation expands eastward into the Lower and Middle Mississippi Valleys. Flash flooding concerns will be elevated for east Texas to southern Illinois/Indiana. Additionally, the mountain snow in Colorado and Wyoming will taper off as the area as the position of the upper low and surface front shifts eastward. The system is forecast to begin a slow eastward movement by Wednesday afternoon and evening, when showers and thunderstorms will begin to spread into portions of the Ohio and Tennessee valleys. Much of the Northeast and Mid-Atlantic states will continue to have pleasantly warm and dry conditions through midweek. Afternoon high temperatures are forecast to be near or above average for mid-April. A vast portion of the West will also remain relatively dry with well-above normal temperatures. Many locations will have afternoon highs ranging 15 to 25 degrees above average through Wednesday. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php