Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 248 AM EST Thu Jan 31 2019 Valid 12Z Thu Jan 31 2019 - 12Z Sat Feb 02 2019 ...Heavy lake effect snow downwind from the Great Lakes... ...Heavy snow for the Sierras and Northern Cascades... ...Heavy rain possible over parts of the California Coast... ...Temperatures will be 15 to 30 degrees below average over the Upper Mississippi Valley, Great Lakes, into parts of the Northern Mid-Atlantic... Cold high pressure over the Upper Midwest/Ohio Valley will slowly move eastward off the East Coast by Saturday. Temperatures will slowly begin to moderate as the air mass slowly warms. The wind chills will range between 50 to 20 degrees below zero over parts of the Upper Midwest on Thursday. The cold air and upper-level energy will aid in producing lake effect snow, that will be heavy at times, downwind from the Great Lakes through Friday. Meanwhile, upper-level energy over the Northern Plains will move southeastward to the Ohio Valley by Friday and off the East Coast by Saturday. The energy will aid in producing light snow over parts of the Northern Plains that will move into the Ohio Valley by Thursday evening and into the Ohio Valley/Central Appalachians by Friday morning. The snow will move into parts of the Northern Mid-Atlantic overnight Friday, ending by Saturday morning. In addition, a front will develop over parts of Central Canada overnight Friday moving southeastward into the Upper Great Lakes by Saturday morning. The boundary will aid in producing light snow over parts of the Upper Great Lakes/Upper Mississippi Valley overnight Friday into Saturday. Additionally, weak upper-level energy over Texas will move eastward to the Eastern Gulf Coast by Friday evening. Moisture from the Gulf of Mexico will move northward over the Western Gulf Coast into the Ohio/Tennessee Valleys by Friday. Rain will develop over parts of the Western Gulf Coast and expanding into parts of Ohio/Tennessee Valleys by Friday. Rain will also develop over parts of Northern Florida on Friday. Elsewhere, upper-level energy will move onshore over California on Thursday moving southeastward into Northern Mexico by overnight Friday. The energy will produce rain over parts of the California Coast moving inland over Southern California and moving into Northern Mexico by Friday evening. In the meantime, a deep upper-level trough will begin to move onshore over the West Coast on Friday morning as an upper-level low develops a long the West Coast of California overnight Friday. Rain will begin to develop over the Pacific Northwest overnight Thursday that will expand inland to Northern California by Friday morning, as snow develops over parts of the Northern Cascades. As the precipitation moves farther inland, overnight Friday, snow will develop over parts of the Northern Rockies and the Sierras. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php