Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 343 PM EST Fri Jan 22 2021 Valid 00Z Sat Jan 23 2021 - 00Z Mon Jan 25 2021 ...Snow for the Great Basin, Central/Southern Rockies, and the Southwest through Sunday... ...Heavy lake-effect snow expected downwind of the Great Lakes through Saturday morning... ...Snow for the Upper/Middle Mississippi Valley on Saturday into Sunday... A two-part storm currently over the West Coast will split with the first wave moving across the Great Basin through Saturday before weakening and the second moving southeastward to the Desert Southwest Saturday night and Southern Plains by Sunday evening. The two systems will produce rain and higher elevation snow across California, Great Basin, Southwest, and the Central/Southern Rockies into Saturday. The snow and rain will end over California Saturday night as the second wave reaches the Desert Southwest. A second round of lower-elevation rain and snow will overspread parts of the Southwest and the Central/Southern Rockies Saturday night into Sunday. The snow will contribute to hazardous driving conditions. Meanwhile, lake-effect snow will continue downwind from the Great Lakes, with the heaviest lake-effect snow falling downwind from Lakes Erie and Ontario where hazardous driving conditions will continue until it wanes Saturday morning. Additionally, a quasi-stationary front across the Gulf Coast States will aid in producing periodic rain over this area through Sunday. Overnight Saturday, the weakening first wave from the West Coast will move out of the Central Rockies onto the Southern Plains pulling moisture off the Western Gulf of Mexico over the Southern Plains aiding in the development of showers and thunderstorms over the Southern Plains, Lower Mississippi Valley, and into parts of the Tennessee Valley on Sunday. Furthermore, a front moving south out of West-Central Canada into the Upper Midwest and the upper-level dynamics associated with the energy moving out of the Central Rockies will aid in producing snow over parts of the Central/Northern Plains on Saturday afternoon. The snow will expand into parts of the Upper/Middle Mississippi Valley Saturday afternoon. The snow will continue to expand eastward into parts of the Upper Great Lakes/Western Ohio Valley through Sunday evening. Rain will also develop over parts of the Middle Mississippi Valley/Western Ohio Valley on Sunday. There will be pockets of light rain/freezing rain along the transition line from rain to snow. The snow and rain/freezing rain will contribute to hazardous driving conditions. In the meantime, a front will begin to move onshore over the Pacific Northwest on Sunday morning, moving inland to parts of the Great Basin by Sunday evening. The system will produce coastal rain and higher elevation snow in Washington and Oregon that will expand into parts of Northern California on Sunday afternoon into evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php