Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 252 PM EST Wed Dec 09 2020 Valid 00Z Thu Dec 10 2020 - 00Z Sat Dec 12 2020 ...Lake Effect snow over the Lower Great Lakes through Thursday morning... ...A storm to develop over parts of the Southwest; Air Stagnation Advisories continue in the Northern Intermountain Region... ...Temperatures will be 20 to 30 degrees above average over parts of the Plains... Upper-level energy and cold air flowing over the relatively warm Great Lakes will aid in producing Lake Effect snow over the Lower Great Lakes through Thursday morning. The snow will help in creating hazardous driving conditions over the region. Meanwhile, upper-level energy over the Northern Intermountain Region will produce light rain and higher elevation snow over parts of the Pacific Northwest, ending overnight Wednesday. The energy will also create light snow over parts of the Northern Intermountain Region through Thursday morning. The snow will aid in producing unsafe driving conditions over the area. South of the snow, Air Stagnation Advisories continue through Thursday morning. Furthermore, an upper-level low over the Northwest Mexican/Southern Californian Coast will steadily move inland over the Southwest and weaken by Friday. The system will begin to produce rain over parts of the Southwest during the early morning on Thursday. By the late morning on Thursday, snow will develop over the Southwest and Southern Rockies' higher elevations. Snow will expand into the Central Rockies overnight Thursday. By Friday morning, rain will develop over parts of the Southern Plains, moving into parts of the Middle/Lower Mississippi Valley by Friday evening. Light snow will also develop over parts of the Central Plains into parts of the Middle Mississippi Valley and Upper Great Lakes on Friday evening. Likewise, any snow will contribute to dangerous driving conditions. In addition, upper-level ridging and flow around an area of low pressure moving out of the Northern Rockies will allow temperatures to become 20 to 30 degrees above average over parts of the Plains Wednesday evening into Thursday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php