Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 259 PM EST Thu Jan 07 2021 Valid 00Z Fri Jan 08 2021 - 00Z Sun Jan 10 2021 ...Periods of heavy precipitation will continue to impact northern California, the Pacific Northwest, and into the northern/central Rockies through the end of the week... ...Light wintry precipitation expected to slide across the Tennessee Valley and into parts of the Mid-Atlantic... ...Rain and some thunderstorms expected across the Deep South and the Southeast... Rain and mountain snow will persist through the end of the week across portions of Pacific Northwest to the Northern/Central Rockies as a cold front advances inland and another system approaches behind it. Light snow will move across the northern Rockies into the northern High Plains today due to a lingering wave of low pressure along a weak front. This weak frontal boundary will fizzle out on Friday. A couple of inches of rain can be expected along the Coastal Ranges of northern California. Meanwhile, 6 to 12 inches of snowfall is forecast for the higher elevations of the Olympic and Cascade Ranges. Precipitation will begin to taper off along the West Coast and areas inland by Friday night, however another bout of light snow will pass over the Central Rockies by early Saturday. Snow, rain and thunderstorms will continue to spread from the Tennessee Valley/Gulf states toward the Mid-Atlantic region as a surface low pressure system traverses the Deep South, the Southeast and the Mid-Atlantic through early on Saturday. With ample amounts of moisture from the Gulf of Mexico feeding into the system, some of these thunderstorms may yield periods of moderate to heavy rainfall. This may lead to areas of localized flash flooding. Wet snow is also expected on the northern periphery of the precipitation shield especially across the southern Appalachians early on Friday where a few inches of accumulation is forecast. A mix of snow and rain will be possible Friday/Friday night across portions of the Appalachians and Mid-Atlantic before the front moves offshore this weekend. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php