Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 412 PM EDT Tue Oct 27 2015 Valid 00Z Wed Oct 28 2015 - 00Z Fri Oct 30 2015 ...Heavy rain possible over parts of the Ohio Valley... ...Heavy rain possible over parts of the Mid-Atlantic into the Northeast... One storm over the Northern Plains and a second over the Lower Mississippi Valley/Central Gulf Coast will merge over the Great Lakes on Wednesday and move northeastward to James Bay Thursday morning. Circulation around the complex storm will pull moisture into the Ohio Valley from the Gulf of Mexico on Tuesday evening and into the Eastern Seaboard from the Atlantic on Wednesday into Thursday. The system will produce rain, with some embedded thunderstorms, from parts of the Upper Mississippi Valley/Upper Great Lakes to parts of the Lower Mississippi Valley eastward to the Mid-Atlantic/Southeast on Tuesday evening. The area of rain will lift northward by Thursday morning extending from parts of the Great Lakes eastward to the Northeast. Before the two systems merge, the first system will produce rain, with a few areas of embedded thunderstorms, from parts of the Northern Plains to parts of the Southern Plains on Tuesday evening into Wednesday morning. Meanwhile, a deep upper-level trough over the Eastern Pacific will move into the West Coast on Wednesday into Thursday morning. The system will produce rain along the Pacific Northwest and the Northern California Coast on Tuesday evening that will move inland to parts of the Northern Rockies/Great Basin on Wedenesday. Onshore flow will aid in continuing the rain over the Northwest/Northern California to the Northern Rockies and expand into parts of the Central/Southern Rockies and the Southwest by Thursday morning. Some of the highest peaks of the Northern/Central Rockies will get snow Wednesday evening into Thursday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php