Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 159 PM EDT Thu Jul 06 2017 Valid 00Z Fri Jul 07 2017 - 00Z Sun Jul 09 2017 ...Flash flooding possible from portions of the Ohio valley to the Mid-Atlantic... ...Severe thunderstorms possible from the Upper Midwest to the central Appalachians... ...Above average temperatures expected for much of the western U.S... A frontal boundary draped from the southern plains and the lower/mid-Mississippi valley to the Mid-Atlantic is expected to continue producing scattered to numerous showers and thunderstorms through tonight. A very moist atmosphere will support heavy rainfall rates, and flash flooding is possible from portions of the Ohio valley to the Mid-Atlantic through early Friday morning. During the day on Friday, the system is forecast to consolidate into a single area of low pressure along the Mid-Atlantic coastline, which will bring numerous showers and thunderstorms from the northern Mid-Atlantic to portions of New England through the day as the system moves northeastward along the coast. A second cold front will bring showers and thunderstorms from portions of the Upper Midwest to the Great Lakes through tonight, and to the Ohio valley and portions of the central Appalachians on Friday. Some storms associated with this system could be severe. The Storm Prediction Center is forecasting a slight to enhanced risk of severe thunderstorms through tonight across portions of the Upper Midwest and the Upper Great Lakes, and a slight risk on Friday/Friday night from portions of the Ohio valley to the central Appalachians. As this front continues its forward progress, it will keep scattered storms a possibility from the southern plains to the Southeast through Saturday. Across the West, a large and anomalous upper-level ridge is forecast to remain anchored across the Four Corners region into the weekend. The subsiding air mass associated with the ridge will support above average temperatures for much of the western U.S., but especially from the interior Northwest to the northern Rockies. Afternoon high temperatures across these areas on Friday and Saturday are forecast to rise well into the 90s to near 100 for some areas, 10 to 20 degrees above average. Record high temperatures may be in jeopardy for some areas. By Saturday, the hot temperatures may also begin to spread eastward into the northern High Plains. The Southwest will also see its share of hot temperatures, with highs expected to be generally 5 to 10 degrees above average. Records could be threatened here as well, especially on Friday. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php