Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 330 AM EDT Thu Apr 02 2015 Valid 12Z Thu Apr 02 2015 - 12Z Sat Apr 04 2015 ...There is a slight risk of severe thunderstorms over parts of the Middle/Lower Mississippi Valley and the Ohio Valley... ...Heavy rain possible from parts of the Middle Mississippi Valley into the Ohio Valley... A front extending from the Upper Great Lakes to the Southern High Plains will move eastward to the Lower Great Lakes to the Lower Mississippi Valley/Western Gulf Coast by Friday evening. Moisture from the Gulf of Mexico will pool along the boundary producing showers and thunderstorms over parts of the Middle Mississippi Valley/Western Ohio Valley that will move eastward to the Central Appalachians to the Lower Mississippi Valley by Friday. In addition, light to moderate rain will develop over parts of the Great Lakes on Thursday afternoon and move eastward off the Northeast Coast by Friday morning. By Friday evening, a new area of light to moderate rain will develop over parts of the Northeast. Additional upper-level energy over the Great Basin will move eastward to the Middle Mississippi Valley by Friday evening. The energy will trigger light snow over parts of the Northern Rockies to the Great Basin that will expand and fill in from the Northern Rockies to the Central Rockies by Thursday evening. Rain will also develop over parts of the Central High Plains on Thursday afternoon into early Friday morning. The snow will wind down over parts of the Central Rockies on Friday morning. Elsewhere, a front will move onshore over the Pacific Northwest on Friday. The system will produce rain and snow at higher elevations on Friday over parts of the Northwest to the Northern Intermountain Region. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php