Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 911 AM EST Sun Feb 03 2019 Valid 12Z Sun Feb 03 2019 - 12Z Tue Feb 05 2019 ...Heavy rain possible over parts of Southern California Coast... ...Heavy snow likely over the Sierras, Northern Rockies, and the Upper Midwest... ...Rain falling on frozen ground will produce freezing rain over parts of the Upper Great Lakes... Temperatures will be 10 to 35 degrees below average over parts of the Northern Plains... An upper-level low over the California will weaken while moving northeastward to the Great Lakes by Monday evening. A second upper-level low, over British Columbia will move southward to Northern California overnight Monday. The systems will produce onshore flow that will aid in producing periods of heavy rain along the California Coast through Monday evening. The storms will also produce heavy snow over the Sierras and over the Cascades through Tuesday morning. The heavy precipitation over Southern California will lead to a risk of flash flooding and debris flows, particularly near burn scar areas, Monday and Monday night. The rain and higher elevation snow will expand inland to the Northern/Central Rockies and the Southwest by Sunday morning, continuing into Monday evening. As the second upper-level low moves southward along the West Coast, snow levels over the Pacific Northwest will lower to the coastline on Sunday evening into Monday. A wave of low pressure along a front extending from the Northeast to the Great Lakes then westward to the Northern Rockies will produce snow and rain over parts of the Upper Mississippi Valley/Great Lakes through Monday evening. Freezing rain will be possible on the frozen ground of the Upper Great Lakes, while rain will develop over the Middle Mississippi and Ohio valleys by Monday. Snow will develop over parts of the Northern High Plains within an increasingly cold air mass on Sunday that will expand eastward into the Northern Plains/Upper Mississippi Valley by Sunday evening. The snow will continue over the area through Monday evening when the snow begins to end. Meanwhile, a weak upper-level low over the Southeast will move off the coast overnight Sunday. The energy will aid in producing low pressure off the Southeast Coast that will slowly move eastward out over the Western Atlantic. Moisture from the Gulf of Mexico will flow northward over the Gulf Coast extending into the Southeast that will aid in producing rain over parts of the Southeast through Monday evening. A front moving into parts of the Southern Plains/Lower Mississippi Valley will aid in producing rain over parts of the Lower Mississippi/Tennessee Valleys on Monday into Tuesday. Another area of cold high pressure over West-Central Canada will move southeastward into parts of the Plains on Monday into Tuesday bringing cold temperatures over the Plains. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php