Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 229 AM EST Wed Jan 31 2018 Valid 12Z Wed Jan 31 2018 - 12Z Fri Feb 02 2018 ...Heavy snow possible over the Upper Great Lakes... ...Snow for the Northern Rockies and Central Appalachians... ...Rain Continues over the Northwest... A front extending from the Upper Great Lakes to the Middle Mississippi Valley into the Central Rockies will move eastward to the Northern/Central Appalachians across parts of the Lower Mississippi Valley/Western Gulf Coast by Thursday evening. The storm will produce snow over parts of the Upper Great Lakes into parts of the Upper Mississippi Valley and Northern Rockies that will move into the Lower Great Lakes/Northeast by Wednesday morning. Overnight Wednesday, the snow moves into parts of Northern New England, ending by Thursday afternoon. In addition overnight Wednesday, a secondary boundary moves into the Upper Great Lakes producing more snow over parts of the Upper Great Lakes/Upper Mississippi Valley that will continue over the Great Lakes through Thursday evening. On Thursday as the primary front moves into the Appalachians, snow and rain develop over the Ohio Valley with the rain and snow moving into the Northern/Central Appalachians by Thursday evening. Additionally, rain will develop along the boundary over the Southern Ohio Valley/Tennessee Valley into parts of the Lower Mississippi Valley later on Thursday morning. The rain will continue along the front from the Lower Mississippi Valley into the Southern Ohio/Tennessee Valleys through Thursday evening. Meanwhile, upper-level energy over the Northern Rockies will move southeastward to the Middle Mississippi Valley by Thursday evening. The energy will aid in producing snow over parts of the Northern Rockies that will continue over the region through Thursday evening. Dome of the snow moves into parts of the Central Rockies on Thursday morning waning by Thursday evening. Furthermore, onshore flow will aid in producing coastal rain and higher elevation snow over parts of the Pacific Northwest that will continue into Thursday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php