Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 254 PM EST Tue Dec 31 2024 Valid 00Z Wed Jan 01 2025 - 00Z Fri Jan 03 2025 ...Coastal storm to bring quick moving round of rain and well-inland snow to the Northeast tonight and New Year's Day... ...Warming trend for the western U.S. while the northern/eastern U.S. experiences colder temperatures through the end of the work week... ...Long duration lake effect snow event expected to begin unfolding tomorrow downwind of the Great Lakes... An area of low pressure located over the Ohio Valley this afternoon will move into northern New York State tonight and weaken, while a secondary low forms along the coast of New England. Rain with thunderstorms will impact the central Appalachians to the Mid-Atlantic coast later this evening and well above average temperatures across the Northeast will keep the precipitation type as rain for most locations except for northern New England. However, colder temperatures will filter into the eastern U.S. behind a trailing cold front which will allow for a changeover to snow for interior portions of the Northeast on New Year's Day as the surface low deepens and slowly tracks northward into eastern Quebec. This storm will mark the beginning of a pattern change for the lower 48 where colder air will sink southward from central Canada into the northern Plains, eventually sweeping eastward. From the northern to eastern U.S., temperatures will fall each day with values approaching average for New England on Thursday while below average temperatures stretch from northern Montana to the Mid-Atlantic and Southeast coasts. The colder air flowing across the still relative warmth of the Great Lakes will set up a favorable pattern for lake effect snow showers, starting tomorrow, which should persist through the end of the week. Snowfall accumulations are expected to be greatest for locations east of Lake Ontario and Erie through Thursday evening with 6 to 12+ inches in the forecast, but additional snow is likely into the weekend as well. Across the West Coast, a series of Pacific fronts will track into northern California, Oregon and Washington over the next couple of days and weaken as they move inland. These systems will bring light, moderate and occasionally heavy rain to the coast of northern California and Oregon where 2 to 4 inches of rain is expected through Thursday evening. Lighter rainfall is expected farther north into western Washington while accumulating snow falls into the Cascade Range, with the highest snowfall accumulations expected for the southern Oregon Cascades through Thursday (6-18 inches, depending on elevation). In addition, an increase in fire weather concerns for parts of southern Texas, southwestern New Mexico and the Transverse Ranges of southern California will exist today, with an Elevated Risk for of the spreading of wildfires lingering in southern California for New Year's Day. Gusty winds and low relative humidities will contribute to the risk. Regarding temperatures, many locations west of the Rockies will experience a warming trend over the next few days as an upper ridge begins to build across the Southwest. Otto Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php