Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 343 PM EDT Fri Jun 08 2018 Valid 00Z Sat Jun 09 2018 - 00Z Mon Jun 11 2018 ...There is a slight risk of severe thunderstorms over parts of the Northern/Central Plains... ...Heavy rain possible over parts of the Middle Mississippi/Ohio Valleys into parts of the Mid-Atlantic... A composite front over Southern Canada and Northeastern U. S. to the Upper Midwest will slowly sink southward to off the Northeast Coast to the Mid-Atlantic then westward to the Middle Missouri Valley by Sunday. Showers and thunderstorms will generally develop from parts of the Mid-Atlantic/Southern New England westward across the Ohio/Middle Mississippi Valleys into parts of the Upper Midwest through Sunday. In addition, an upper-level low over Florida will aid in producing showers and thunderstorms over parts of the Southeast and Southern Mid-Atlantic through Sunday, too. Furthermore, southerly flow out of the Western Gulf of Mexico will aid in producing showers and thunderstorms over the Western Gulf Coast also through Sunday. Additionally, a far western dryline along with the moisture to the line's east and daytime heating will aid in producing showers and thunderstorms over the Southern High Plains, likewise, through Sunday. Meanwhile, a slow moving front extending from parts of the Pacific Northwest southward into Northern/Central California will move eastward to the Northern High Plains into the Great Basin by Sunday. A deep upper-level trough associated with the front will, similarly, move slowly eastward inland over the West Coast. The system will produce rain over parts of the Pacific Northwest that will advance inland to parts of the Northern Intermountain Region and Northern California by Saturday morning. The storm will continue to produce rain over the Pacific Northwest into parts of Northern California through Sunday. As the upper-level trough moves inland, rain and snow will develop over the highest elevations of the Cascades from Saturday afternoon into Sunday. As the front moves into the Northern Intermountain Region, showers and thunderstorms will develop along and ahead of the boundary on Saturday afternoon that will expand eastward into parts of the Northern Rockies/Northern High Plains. Behind the front rain will develop with rain and snow over the highest elevations by Sunday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php