Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 PM EDT Thu Aug 16 2018 Valid 00Z Fri Aug 17 2018 - 00Z Sun Aug 19 2018 ...There is a slight risk of severe thunderstorms and flash flooding over parts of the Central/Southern Plains and the Middle/Lower Mississippi Valley... ...Monsoonal rains bring flash flooding concerns to the Southwest... ...Fire Weather Concerns continue across the western U.S.... A quasi-stationary front currently extends from coastal New England southwestward through the Great Lakes, Middle Mississippi Valley and into the Southern Plains. Warm moist unstable air from the Gulf of Mexico is flowing northward towards the frontal boundary, allowing for scattered to numerous showers and thunderstorms along the frontal boundary. This boundary is expected to slowly shift eastward heading into the weekend, along with the best shower and thunderstorm potential. The Storm Prediction Center has outlined a region encompassing northeast Oklahoma, Southeast Nebraska, southwest Missouri, and far northwest Arkansas as being in a slight risk for seeing severe thunderstorms today through tonight. The Weather Prediction Center has outlined an area along this frontal boundary from the Southern Plains to the Tennessee Valley as being in a slight risk of seeing excessive rainfall and flash flooding through tonight. This slight risk area will shift eastward into Kentucky and southern Indiana for Friday. Flash flood watches and warnings are currently in effect for portions of Oklahoma. Flash Flood watches are also in effect across north-central Kentucky and south-central Indiana. Given the strong pull of warm air into the region, Heat Advisories are also in effect for portions of the Southern Plains and the Lower Mississippi Valley. Monsoonal moisture is also making its way into the Southwest. Excessive rainfall is likely here through tonight, as is outlined by the Weather Prediction Centers slight risk across much of the region, and Flash Flood Watches and Warnings ongoing. This same airmass will cause widespread fire weather concerns across other portions of the West. Scattered thunderstorms will be likely, however a very dry near-surface layer will prevent much moisture from making it to the ground. Any lightning that occurs out of these storms could easily induce new wildfires. Red Flag Warnings and Fire Weather Watches are currently in effect across much of Oregon, Idaho, southeast Washington and western Montana through at least this evening. Furthermore, ongoing wildfires continue to pollute the air with large amounts of smoke. Air Quality Alerts remain in effect across Central California, as well as much of Oregon, Washington, Idaho, and northwest Montana. Wix Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php