Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 341 PM EDT Wed Jul 17 2019 Valid 00Z Thu Jul 18 2019 - 00Z Sat Jul 20 2019 ...Post-Tropical Cyclone Barry remains a flooding threat for portions of the northern Mid-Atlantic and Southern New England... ...Flash flooding and severe weather are both possible from the Northern Plains to the Upper Midwest/Great Lakes through Thursday... ...A dangerous heat wave continues to grip much of the country from the Plains to the East... Post-Tropical Cyclone Barry continues to weaken this afternoon with the center of circulation expected to become less and less distinct through tonight. Tropical moisture associated with Barry will interact with a frontal boundary to its north resulting in heavy rainfall and scattered thunderstorms across the northern Mid-Atlantic to southern New England. Rainfall amounts of 1 to 2 inches, with locally higher amounts, are forecast and WPC has a slight risk for excessive rainfall/flash flooding in place through early Thursday morning. SPC also indicates a slight chance for severe weather across parts of the same region tonight. Lingering tropical moisture farther south may also result in pockets of heavy rainfall across the Tennessee Valley and Southern/Central Appalachians. A series of slow moving frontal boundaries across the north-central U.S. will bring showers and thunderstorms from the Upper Great Lakes to the Northern and Central Plains the next few days. The best chance for heavy rainfall and strong to severe storms this evening and tonight will be across the Upper Midwest and portions of the Northern Plains, with the threat shifting slightly eastward into the Upper Great Lakes on Thursday and into Friday. The biggest story in the short range though is a strengthening upper level ridge across the Central and Eastern U.S. resulting in oppressive and dangerous heat across the eastern two thirds of the country. Widespread excessive heat warnings, watches, and heat advisories are in effect across much of the Central U.S., into the Ohio Valley, and along parts of the Eastern Seaboard. Daytime highs in the 90s to near or above 100 are expected, and combined with dewpoints soaring into the mid to upper 70s, will result in heat indices (feels like temps) as high as 110 in some places. Temperatures overnight will struggle to recover much with near or surpassing record values in the mid to upper 70s or near 80 for many. The dangerous heat will also continue or worsen over the weekend beyond the short range period. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php