Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 426 PM EDT Thu May 31 2018 Valid 00Z Fri Jun 01 2018 - 00Z Sun Jun 03 2018 ...There is a slight risk of severe thunderstorms over parts of the Ohio/Tennessee/Middle Mississippi Valleys... ...There is a slight risk of severe thunderstorms over parts of the Northern High Plains/Northern Rockies... ...Heavy rain possible over parts of the Northern Plains and Lower Mississippi Valley... Two areas of upper-level energy over the Great Lakes and the Ohio/Middle Mississippi Valleys will merge into an upper-level low over the Mid-Atlantic and Central/Southern Appalachians by Saturday. Deep moisture over the region will interact with the upper-level energy to produce showers and thunderstorms over the Great Lakes to the Middle Mississippi Valley eastward to the Northeast/Mid-Atlantic Coast that will end over the Upper Great Lakes and Middle Mississippi Valley by Friday afternoon. The showers and thunderstorms will being to move off the Eastern Seaboard by Saturday morning while continuing over parts of the Appalachians. In addition, with the very moist air over the Southeast along with daytime heating will aid in producing showers and thunderstorms over the region through Saturday. Meanwhile, a deep upper-level trough over the West Coast will move eastward to the Plains by Saturday. The system will produce showers and thunderstorms over parts of the Northern Rockies/Northern High Plains into parts of the Great Basin that will steadily move eastward to the Northern/Central Plains by Saturday morning. Additionally, showers and thunderstorms will develop over parts of the Southern Plains a long and ahead of the dryline on Friday afternoon into late evening. Elsewhere, onshore flow will aid in producing rain over parts of the Pacific Northwest Coast that will end overnight Thursday as upper-level ridging builds over the area. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php