Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 412 PM EDT Wed May 16 2018 Valid 00Z Thu May 17 2018 - 00Z Sat May 19 2018 ...A wet pattern will continue this week across parts of the Eastern U.S. with flash flooding possible... ...Severe thunderstorms and heavy rainfall possible across the portions of the Great Plains late Thursday into Friday... Parts of the Eastern U.S. from the Deep South to the Mid-Atlantic will stay in a persistent wet and stormy pattern through the rest of the week as tropical moisture out of the Gulf of Mexico interacts with a nearly stationary frontal boundary draped across the region. The best chance for heavy to excessive rainfall will be along the boundary from the central Appalachians to the Mid-Atlantic in association with a weak disturbance lifting northward across the Deep South. WPC has highlighted this region in a slight risk for excessive rainfall from tonight through early Friday. Scattered to widespread showers and thunderstorms will likely develop across the Great Plains by Thursday afternoon as upper level energy slides through aloft. Conditions may be favorable for severe thunderstorms to develop, especially across the central and northern High Plains, and the Storm Prediction Center has this region in a slight risk for severe weather on Thursday and Friday. A cold front dropping into the northern Plains late Thursday and into Friday should also provide a focus for heavy rain with WPCs excessive rainfall/flash flood graphic showing a slight risk across portions of the Dakotas. Meanwhile out west, active weather should continue as a weakening upper level low drifts eastward through the Great Basin and into the central Rockies. Showers and thunderstorms can be expected through the next few days across much of the Northwest, with localized enhanced activity along the favored terrain. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php