Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 349 AM EST Wed Jan 08 2025 Valid 12Z Wed Jan 08 2025 - 12Z Fri Jan 10 2025 ...Moderate to heavy lake-effect snow downwind from the Great Lakes on Wednesday... ...A developing Winter Storm will produce snow and rain/freezing rain, icing, over parts of the Southern Plains and Lower Mississippi Valley late Wednesday night into Thursday... ...Light to moderate snow over parts of the Northern Rockies/Northern Plains and Southern Rockies/Southern High Plains on Wednesday: Light snow over parts of the Upper Midwest on Thursday... ...There is an Extremely Critical Fire Weather Area for portions of the Southern California Coast... Cold high pressure extending from the Central Plains to western Ontario, Canada, moves to the Mid-Atlantic by Friday. The cold air and upper-level energy will aid in producing moderate to heavy lake-effect snow downwind from the Great Lakes on Wednesday and will begin to taper off on Thursday. In addition, moderate to heavy upslope snow will develop over parts of the Northeast, and light to moderate upslope snow over the Central Appalachians will develop on Wednesday. Meanwhile, strong high pressure over parts of the Great Basin and low pressure dropping into the Gulf of California will continue to support Santa Ana winds and a dangerous fire weather event over portions of Southern California on Wednesday. The SPC has issued a Extremely Critical Fire Weather Area along portions of the Southern California Coast. Sustained winds reaching 30 to 40 mph, with stronger winds in the terrain, along with low relative humidity, and dry fuels will contribute to the dangerous conditions. Critical fire weather conditions are expected to continue on Thursday for portions of Southern California. Moreover, on Wednesday, a deep upper low over Northwestern Mexico will open and move to the Southern Rockies to the Southern Plains by Friday. The system will create impactful winter weather on Thursday for portions of the Southern Plains before intensifying as it expands across the Lower Mississippi Valley overnight Thursday into Friday. Snowfall totals will be the greatest, 4 to 8 inches, from portions of North Texas across Arkansas into the Tennessee Valley. Hazardous driving conditions can be expected through the swath of winter weather. Additionally, rain/freezing rain will develop over parts of Central Texas into southern Arkansas and northern Louisiana. Over this region, scattered ice amounts of 0.10 inches will fall on Thursday. Furthermore, additional upper-level energy will move over the Pacific Northwest/Northern Intermountain Region Wednesday morning and reach the Southern Rockies and the Upper Great Lakes by Friday. The energy will aid in the development of a new front over the Northern/Central Plains into the Central Rockies that will move eastward to the Upper Great Lakes to the Southern Plains by Friday. The new energy will create a short-lived light coastal rain and higher-elevation snow over parts of the Pacific Northwest on early Wednesday morning. By Wednesday evening, light snow will develop over parts of the Northern Rockies, expanding into parts of the Northern Plains and Central Rockies by Thursday morning. By Thursday night, light snow will extend from the Northern Plains/Upper Mississippi Valley to the Central/Southern Rockies and Central/Southern Plains. By Friday morning, the light snow will move into the Upper Great Lakes and Middle Mississippi Valley, while continuing over the Southern Plains. Moreover, by Friday, a new front moving onshore over the Pacific Northwest will trigger coastal rain and higher-elevation snow over parts of the Pacific Northwest. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php