Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 339 AM EDT Fri Mar 27 2015 Valid 12Z Fri Mar 27 2015 - 12Z Sun Mar 29 2015 ...Temperatures will be 15 to 25 degrees below average for parts of the Mississippi Valley/Ohio Valley and the Great Lakes... A surface low and associated front over the Southeast will move northeastward out over the Atlantic by Friday evening. The system will produce showers and thunderstorms over parts of the Southeast that will move eastward off the Southeast Coast by late Friday afternoon. Light to moderate rain will also develop over parts of the Southern Mid-Atlantic that will likewise move eastward off the Mid-Atlantic Coast by later Friday evening. In addition, a deep upper-level trough over the Midwest will move to the East Coast by Saturday evening. The energy will aid in producing areas of light snow over parts of the Great Lakes and Central Appalachians through Saturday morning. The energy will also produce snow over parts of the Northeast Coast on Saturday. Additionally,upper-level jet dynamics will aid in producing an area of light snow over parts of the Northern/Central Plains that will move southeastward to the Middle Mississippi Valley by Saturday morning. Meanwhile, a front moving onshore over the Pacific Northwest by Friday evening, will move eastward to the Northern Plains/Great Basin by Saturday evening. The system will produce light to moderate rain over parts of the Northwest Coast that will move inland to parts of the Northern High Plains by Saturday evening. Rain will linger over parts of the Pacific Northwest Coast through Saturday morning. Rain will also develop over part of the Northern Plains/Upper Mississippi Valley by Saturday evening, too. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php