Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 257 PM EST Wed Jan 17 2024 Valid 00Z Thu Jan 18 2024 - 00Z Sat Jan 20 2024 ...Heavy mountain snows for the Northwest/Rockies... ...Bands of heavy lake-effect snow continue for the Great Lakes through Thursday with hazardous snow across the Midwest and Mid-Atlantic into Friday... ...Another Arctic blast expected late this week... A storm system moving into the Pacific Northwest this afternoon will continue to spread heavy mountain snows across the Cascades and into the Northern/Central Rockies tonight and into Thursday, with moderate to major winter storm impacts expected owing to high snowfall rates and blowing snow. Widespread winter storm warnings and winter weather advisories are in effect. Some freezing rain is possible as well across the Willamette Valley, Portland metro, and Columbia basin, on top of what fell there early Wednesday. Along the coast, rain is expected which could be heavy in spots. Rainfall should expand in coverage into northern California Thursday and Friday, with localized flash flooding a concern. Lake effect snow bands will continue downwind of the Great Lakes, particularly Lakes Erie and Ontario where an additional 1-3 feet are possible through Thursday night. Some light snow is also possible across the Ohio Valley/Midwest on Thursday along a frontal boundary. The next system will track into the Plains by Thursday with snow likely to track from the north-central Plains to the Midwest/Lower Great Lakes on Thursday and the Mid-Atlantic on Friday. Although significant accumulations are not expected, the snow could still create hazardous driving conditions and reduced visibilities at times. The Southern Plains and Gulf Coast may get a brief break in the cold on Thursday as temperatures rebound into the 60s and 70s. This will be short lived however as another frigid Arctic airmass will once again overspread the Eastern Half of the country by later this week. Although not as extreme as the first wave early this week, daytime highs on Friday across the Plains into the Mississippi Valley could be 20-30 degrees below normal, with wind making it feel even colder. This cold will spread into the Eastern U.S. this weekend. Santorelli Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php