Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 215 AM EST Thu Jan 16 2025 Valid 12Z Thu Jan 16 2025 - 12Z Sat Jan 18 2025 ...Improvement in fire weather conditions across southern California... ...A brief moderation of temperatures across the central U.S. before an arctic front plunges into the northern U.S. on Friday... ...Lake effect snow expected on Thursday and snow also expected for the central Appalachians... There will be a few things making weather headlines through Friday night across the country. Lake effect snow is expected in the wake of a shortwave passage, and the heaviest snowfall will be downwind of Lake Erie across western New York on Thursday, where lake effect snow warnings are now in effect. Moderate to heavy snow is also on the way for the central Appalachians with moist upslope flow leading to 5-10 inches of accumulation across the higher terrain of West Virginia into south-central Pennsylvania, where winter storm warnings are in effect. A pattern change will evolve across the Central U.S. and the Rockies going into Friday and especially into early Saturday. After a brief moderation in temperatures across the north-central U.S. on Thursday, an abrupt change to reality is coming by Friday as a pair of strong cold fronts heralds the arrival of frigid temperatures and brutally cold wind chills. This will continue well beyond the short range forecast period, and the Weather Prediction Center has Key Messages regarding this arctic blast. This could also be accompanied by some snow showers and a few snow squalls across the northern Rockies and western High Plains going into Friday and Friday night, resulting in mainly light accumulations but accompanied with poor visibilities and gusty winds. For the Eastern U.S., a gradual moderation trend in the recent very cold conditions is on the way to conclude the work week with readings returning to near seasonal averages for the East Coast, and above average for much of the Southeast states. A developing low pressure system over the Deep South Friday night will likely lead to increasing showers and perhaps a few thunderstorms near the central Gulf Coast region by Saturday morning, but this region should remain dry until then. Things are starting to look better in terms of the forecast across California and the areas that have been devastated by the ongoing wildfires. Even though no rain is in the forecast, the winds are expected to switch to a more onshore flow late Thursday and into Friday, bringing higher relative humidities and less chaotic wind flow, thus helping to mitigate the wildfire threat compared to recent days. Hamrick Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php