Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 455 AM EST Tue Jan 07 2025 Valid 12Z Tue Jan 07 2025 - 12Z Thu Jan 09 2025 ...Moderate to heavy lake-effect snow downwind from the Great Lakes on Tuesday and Wednesday... ...A Developing Winter Storm will produce snow and rain/freezing rain, icing, over parts of Texas on Wednesday... ...Light snow over parts of the Great Basin, Southwest, and Central/Southern Rockies on Tuesday and over the Northern Rockies/Northern High Plains on Wednesday... ...There is a Critical Risk of fire weather over parts of Southern California on Tuesday and Wednesday, with an Extremely Critical Risk for portions of Los Angeles and Ventura counties on Wednesday... Cold high pressure over the Northern High Plains will move southeastward to the Ohio Valley by Thursday. The cold air and upper-level energy will aid in producing moderate to heavy lake-effect snow downwind from the Great Lakes through Thursday. In addition, moderate to heavy upslope snow will develop over parts of Northern New England, and light to moderate upslope snow over the Central Appalachians will develop through Thursday. Meanwhile, strong high pressure will develop over parts of the Great Basin, setting up Santa Ana winds over Southern California on Tuesday, that will continue into Wednesday. Therefore, the SPC has issued a Critical Risk Fire Weather Outlook over parts of Southern California on Tuesday and Wednesday, with an Extremely Critical Outlook for portions of Los Angeles and Ventura counties on Wednesday. Winds of 20 to 25 mph on Tuesday, increasing up to 40 mph on Wednesday, with stronger gusts in terrain-favored areas, along with low relative humidity, and dry fuels will contribute to dangerous conditions. Moreover, on Tuesday, upper-level energy over Southern California will move southward to Northwestern Mexico, creating a deep upper low over the region by Wednesday. The energy will begin to move eastward over Northern Mexico by Thursday. By Tuesday morning, light to moderate snow will develop over parts of the Great Basin and the Northern/Central Rockies. Light to moderate snow will develop over parts of the Southern Rockies by Tuesday evening. The system will produce light snow over West Texas on Wednesday before a more significant storm on Thursday. Many areas from northern Texas, including the Dallas-Fort Worth Metroplex, will have at least some chance (>30%) of wintry weather. With cold air already in place, a wintry mix of snow, sleet, and freezing rain is forecast for the Southern Plains, which may cause hazardous driving conditions, starting late Wednesday night and continuing into Thursday morning. Further, additional upper-level energy will move over the Pacific Northwest Wednesday morning and reach the Central Rockies by Thursday, aiding in the development of a new front from the Northern/Central Plains into the Central Rockies. 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. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php