Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 251 AM EST Tue Jan 21 2025 Valid 12Z Tue Jan 21 2025 - 12Z Thu Jan 23 2025 ...Dangerously cold temperatures and wind chill values to linger for much of the South and eastern U.S. through mid-week... ...Rare winter storm to bring heavy snow as well as areas of sleet and freezing rain to the Gulf Coast and Southeast with widespread travel impacts expected... ...Extremely Critical Risk of fire weather for southern California will continue into Tuesday... A bitterly cold airmass will remain in place for much of the South and eastern U.S. over the next couple of days following an Arctic frontal passage over the holiday weekend. Forecast temperatures on Tuesday will be upwards of 20-30 degrees below January averages for most locations with highs ranging from the single digits and teens in the Midwest, the teens and 20s in the Northeast, and the 20s and 30s across the central/southern Plains and Southeast. Many record lows are possible Wednesday morning, especially along the Gulf Coast and into the Tennessee Valley. Sub-zero wind chills will continue for the central/southern Plains and Ohio Valley, and may expand into the Mid-Atlantic and Mid-Mississippi Valley through Wednesday. After another brutal morning with dangerous wind chills reaching 30 to 55 degrees below zero, portions of the northern Plains will see a return to relatively warmer, more typical January temperatures in the 20s and 30s by Tuesday afternoon as downsloping air from the Rockies spreads eastward across the region. These temperatures will reach the Upper Midwest by Wednesday, while temperatures will also moderate into the 40s and 50s for western portions of the central/southern Plains. The combination of this Arctic air reaching the Gulf Coast and a developing low pressure system over the Gulf will lead to a rare, significant winter storm for the Gulf Coast and Southeast the next couple of days. A historic snowfall is possible along the Gulf Coast, with snowfall rates of 1"/hour or more possible from eastern Texas through the western Florida Panhandle. This may produce snowfall totals as much as 3-6" for the I-10 corridor, including the cities of Houston, New Orleans, Mobile, and Pensacola. A combination of heavy snow, sleet, and freezing rain is expected further east into Georgia, northern Florida, and the eastern Carolinas. This storm may lead to major highway and air traffic disruptions, including possible road closures and flight cancellations, which may continue for several days even after the snowfall ends. Power outages are also possible and will exacerbate the threat from the frigid temperatures. Unfortunately, dangerous fire weather conditions look to continue through at least mid-week for southern California with very strong offshore flow and low humidity in place. The Storm Prediction Center has outlined an Extremely Critical Risk of fire weather (level 3/3) for the regional mountains around the LA Basin as wind gusts may reach 70-100 mph. A Critical Risk (level 2/3) is also in place for the regional valleys and coastal regions with gusts of 50-80 mph expected. A Critical Risk continues for the mountains Wednesday. Elsewhere in the West, conditions will be dry, with generally mild high temperatures. Forecast highs range from the 40s and 50s for the Pacific Northwest and Great Basin, the 50s and 60s in California, and the 60s and 70s in the Desert Southwest. Morning lows will be a bit chilly, however, and may drop close to freezing for more sensitive areas of the Desert Southwest and the central California Valleys. Elsewhere, scattered showers and thunderstorms are expected across Florida. Bands of heavy lake effect snow will continue the next couple of days for favorable downwind locations of the Great Lakes with persistent northwesterly flow in place. A clipper system dropping south from Canada into the northern Plains and Upper Midwest will bring some snow showers through mid-week. Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php