Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 529 AM EDT Wed May 15 2019 Valid 12Z Wed May 15 2019 - 12Z Fri May 17 2019 ...There is a Slight Risk of severe thunderstorms over parts of the Northern Plains/Upper Mississippi Valley... ...Heavy snow is expected in the highest elevations of the Sierra Nevada... ...Temperatures will be 10 to 15 degrees above average over parts of the Northern/Central High Plains... A front over the Upper Great Lakes will move southeastward to Southern New England and the Northern Mid-Atlantic Coast by Thursday morning, then off the coast by Thursday evening. The boundary will aid in producing rain over parts of the Upper Great Lakes that will move into the Lower Great Lakes by Wednesday evening. Overnight Wednesday, the rain will expand into parts of the Northeast moving off most of the Northeast Coast by Thursday afternoon. Rain will linger over parts of Northern New England through Thursday evening. Meanwhile, weak upper-level energy over parts of the Middle Mississippi Valley will move southeastward to off the Southern Mid-Atlantic/Southeast Coast by late Wednesday night. Another area of upper-level energy will follow a similar path on Thursday morning through Friday morning. The energy will aid in producing showers and thunderstorms over parts of the Middle/Lower Mississippi Valley that will move into the Tennessee/Southern Ohio Valleys by Wednesday evening. On Thursday, the showers and thunderstorms will re-fire over parts of the Middle Mississippi Valley into the Tennessee Valley and move into the Central/Eastern Gulf Coast Thursday night. Another front over parts of the Northern High Plains into the Great Basin will move eastward to the Upper Great Lakes by Thursday evening with a trailing front extending across the Middle Mississippi Valley, Central Plains, and banked up against the Central/Northern Rockies. Showers and thunderstorms will develop over parts of the Northern High Plains that will move into the Northern Plains by Wednesday evening. The showers and thunderstorms will continue to move eastward to the Upper Great Lakes into the Ohio Valley by Thursday evening. A developing upper-level low will move onshore over Northern California by Thursday morning, continuing to move inland to the Great Basin by Friday. The system will produce rain over parts of Northern California that will expand into parts of the Pacific Northwest/Northern Intermountain Region and Central California/Great Basin by Wednesday evening. Overnight Wednesday, rain will move into Southern California and heavy snow will occur in the higher elevations of the Sierra Nevada. Rain will expand into parts of the Northern Rockies and Eastern Great Basin with showers and thunderstorms developing over parts of the Northern High Plains by Friday. Snow will continue to fall over the Sierra Nevada and in some of the higher elevations of the Great Basin through Friday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php