Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 246 AM EST Fri Feb 16 2024 Valid 12Z Fri Feb 16 2024 - 12Z Sun Feb 18 2024 ...Swath of accumulating snow will spread from Midwest today to Mid Atlantic tonight... ...Heavy Rain and mountain snow to impact California this weekend... ...Chilly air sweeps across much of the central and southern parts of the country this weekend... A quick moving low pressure system will sweep across the Southeast and Tennessee Valley today before exiting into the Western Atlantic later tonight. An area of light to moderate snowfall will develop over the northern periphery of this system, going on to produce a general swath of 2-4" of snow from eastern Missouri to southern New Jersey/Delaware. Heavier snowfall will occur over the Central Appalachians of West Virginia into the Maryland Panhandle where 4-6" with locally higher amounts are possible. The timing of this snowfall could cause issues during rush hour commutes across the Midwest today. Late night travel could be dicey from the DC up to Philadelphia metros this evening. Elsewhere, a deep southern stream trough will support rain showers and thunderstorms across parts of the Texas/Central Gulf Coast through tonight. Shortwave energy moving through the Rockies will promote moderate to heavy snowfall over the Northern and Central portions of the mountain range through this evening as well. An Arctic airmass will work it's way through the Central and Southern parts of the country this weekend as an associated Arctic cold front propagates through. Temperatures across parts of the Great Plains, Mississippi Valley and eventually Southeast will be between 15-25 degrees below average this weekend. A deep upper-level low over the Eastern Pacific will send a plume of moisture into the West coast on Saturday. This moisture will be supported by a low pressure system and an attendant cold front at the surface. Heavy Rain will develop across southern Oregon and northern California tonight before spreading south into central/southern California on Saturday. There's a Slight Risk of Excessive Rainfall (level 2/4) leading to Flash Flooding for portions of Humboldt County down to Sonoma on Saturday where between 1-2"/hr rainfall rates are possible. Heavy snow will develop over the Sierra Nevada and Shasta/Trinity on Saturday night as Pacific moisture move inland. Another low pressure system will bring yet another round of heavy precipitation to California on Sunday. Heavy rainfall from the prior day in addition to the general sensitivity of California's coastal areas to heavy rainfall will support a Slight Risk of Flash Flooding from Humboldt County down to Ventura on Sunday. This moisture will eventually shift into the Sierra and Trinity/Shasta once again, and will support additional moderate to heavy snowfall over those mountain ranges. A total of 1-2 feet of snow are possible over the Sierra this weekend while 1-3 feet are more likely over the Trinity and Shasta Mountains. Kebede Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php