Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 AM EDT Wed Jul 17 2019 Valid 12Z Wed Jul 17 2019 - 12Z Fri Jul 19 2019 ...Post-Tropical Cyclone Barry remains a flooding threat for portions of the Ohio Valley into the Mid-Atlantic and Northeast... ...Flash flooding and severe weather are both possible in the Upper Midwest today... ...A dangerous heat wave is beginning to build into the central and eastern U.S.... Post-Tropical Cyclone Barry is expected to move eastward through the Ohio Valley today and along the Pennsylvania/New York border tonight. As tropical moisture flows in and a front moves slowly southward into the Lower Great Lakes region and Northeast, heavy rain remains possible along its track. With rainfall amounts of 1 to 3 inches forecast, a Slight Risk of excessive rainfall/flash flooding is in place for eastern portions of the Ohio Valley into northern portions of the Mid-Atlantic and the Northeast today and tonight. Tropical moisture lingering in the Tennessee Valley could lead to heavy rain and the potential for flash flooding today in that area as well. Frontal systems along with upper-level impulses are expected to pass through the north-central U.S. on Wednesday and Thursday, leading to scattered thunderstorms. Some thunderstorms could be severe and contain heavy rain, and Slight Risks of both flash flooding and severe weather are in place today across the Upper Midwest. The Northern High Plains could also see severe storms today. The greatest threat for flash flooding shifts a bit eastward on Thursday into the Upper Great Lakes region. On Wednesday and Thursday, temperatures are forecast to be above average for the central and eastern U.S. The heat and the humidity will combine to create dangerous heat indices. Widespread Excessive Heat Warnings and Watches and Heat Advisories are in effect for much of the Plains, Mississippi Valley, and into the Ohio Valley, as well as portions of the Eastern Seaboard. The next couple of days are just the beginning as heat is expected to worsen over the weekend. Meanwhile, the West Coast into the Northern Great Basin and Northern Rockies will be cooler than average over the next couple days behind a cold front. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php