Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 332 PM EDT Wed Jul 19 2017 Valid 00Z Thu Jul 20 2017 - 00Z Sat Jul 22 2017 ...There is an enhanced risk of severe thunderstorms over parts of the Upper Mississippi Valley and Northern Plains... ...Heavy rain possible over parts of the Upper Mississippi Valley, Great Basin and Desert Southwest... ...Temperatures will average 10 degrees above seasonal normal across portions of the central USA... Scattered to widespread showers and thunderstorms are expected from the northern High Plains to the Great Lakes region through the end of the week along a slow moving boundary. Multiple rounds of convection will likely develop over the next few days producing 1 to 4 inches over much of the Upper Mississippi Valley. This will increase the risk for flash flooding through the end of the week. Additionally, some of these storms may become severe today across portions of northern High Plains and the Upper Mississippi Valley- with a continuing slight risk through Friday from the northern High Plains to the Great Lakes region. Please refer to the SPC webpage for additional information on the risk for severe weather. Monsoonal moisture, combined with daytime heating along with upper-level energy, will trigger showers and thunderstorms over parts of the Desert Southwest/Great Basin eastward into parts of the Central/Southern Rockies through Friday morning. The showers and thunderstorms will have the greatest areal coverage during the afternoon and evening hours and may potentially produce periods of heavy rain. An increased risk for flash flooding will persist across this region through Friday. Weak onshore flow will generate rain showers to the Pacific Northwest Coast through Thursday. Afternoon and evening showers and thunderstorms are forecast for much of the Gulf Coast, Southeast and southern Mid-Atlantic over the next couple of days as upper-level energy interacts with a very warm and moist airmass. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php