Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 337 PM EST Wed Dec 21 2016 Valid 00Z Thu Dec 22 2016 - 00Z Sat Dec 24 2016 ...Heavy snow for the Sierras... ...Heavy snow for the San Juan Mountains... ...Heavy rain possible for parts of the Pacific Northwest/Northern California... ...Snow possible from parts of the Upper Mississippi Valley/Upper Great Lakes to Northern New England... Low pressure over the Great Lakes will move eastward off the Coast of Maine by Thursday evening. The system will produce snow over parts of the Upper Mississippi Valley/Upper Great Lakes on Wednesday evening that will move into the Lower Great Lakes/Northeast by Thursday morning. The snow will move off the Northeast Coast overnight Thursday. In addition, rain will develop over parts of Southern New England on Thursday ending by Thursday evening. Meanwhile, a weakening upper-level low off the West Coast of Mexico will move northeastward to the Central/Southern Rockies by Friday morning. Moisture from the Pacific will move into parts of the Southwest/Southern California through Thursday afternoon. The storm will produce showers and thunderstorms parts of the Southwest/Southern California that will that will move into parts of the Southern Rockies by Thursday evening. Overnight Wednesday, snow will develop over parts of the Great Basin/Central Rockies and the Central High Plains that will expand into parts of the Central Plains/Middle Mississippi Valley Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php