893 FXUS61 KLWX 302356 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 656 PM EST Tue Dec 30 2025 .SYNOPSIS... An upper-level disturbance will pass through late tonight into Wednesday morning before another upper-level disturbance and its reinforcing cold front move through late Wednesday night into Thursday morning. High pressure will briefly return for Friday before low pressure passes nearby or to our south Saturday. High pressure will return for Sunday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... An area of stratocumulus remains evident along and west of the Appalachians, spilling over into north-central MD and the eastern WV panhandle as of early this evening. Some flurries continue along the ridges of western MD and eastern WV mainly along and west of the Allegheny Front. Winds will continue to gradually subside tonight as the gradient continues to weaken along with the loss of diurnal mixing. An upper-level disturbance in the northern stream will move into the area late tonight. This system will lack a substantial moisture source, but most guidance shows upward motion in the mid-levels that is aligned with saturation and the DGZ. This will obviously fight low-level dry air, but flurries and perhaps even a period of light snow cannot be ruled out. As of now, it appears that the best chance will be near/west of the Allegheny Front. Those areas could actually pick up a couple of inches overnight into early Wednesday morning. Across our eastern areas (northeast Maryland and perhaps down through the Baltimore and DC metro areas into southern Maryland), have increased POPS a good bit today given a lot of agreement between hi-res guidance and even the Euro this afternoon that there is at least a 20-30% chance of a light coating of snow. If accumulating snow does occur, even light amounts would have an impact due to the very cold conditions and this would impact the Wednesday morning commute. A Special Weather Statement was issued for this threat, highlighting the potential impacts on the morning commute. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... The upper-level disturbance will depart Wednesday morning and any flurries or light snow should dissipate by mid-morning, except for along/west of the Allegheny Front where some snow showers may linger. Do think there will be a lull out there prior to the bigger system arriving in the afternoon. Dry and chilly conditions are expected for most areas later Wednesday morning into Wednesday evening behind the departing upper-level disturbance. Another upper-level disturbance in the northern stream along with a reinforcing cold front will pass through the area late Wednesday night into Thursday morning. This system will be a bit stronger, despite limited moisture east of the mountains. Another period of light snow or flurries is possible, and again with cold conditions any light accumulation may be impactful. However, for locations along and west of the Allegheny Front, an upslope component to the low-level wind will bring heavy accumulating snowfall. A Winter Storm Warning is now in effect for areas west of the Allegheny Front, with western Highland and extreme western Allegany Counties both in Winter Weather Advisories. The combination of the upslope flow, strong mid- level forcing and saturation within the DGZ along with instability and high SLRs suggest that significant accumulation is possible (around 6" along and west of the Allegheny Front). Strong winds gusting to around 40 to 50 mph will also create poor visibility at times, with near-blizzard conditions possible. Of particular concern is the timing, with the onset of the worst conditions likely occurring right around, or just before, midnight on New Year's Eve/New Year's Day. When all is said and done, areas in the warnings could see anywhere from 6 to 9 inches, with the areas in advisories between 2 and 4 inches. High pressure will build overhead behind this system later Thursday through Thursday night, bringing more dry and cold conditions. Gusty northwest winds Thursday into Thursday evening will make it feel blustery as well. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Surface high pressure builds overhead beginning Friday and persists through the weekend. Overall, dry conditions are expected each day with high temperatures in the 30s to mid 40s. Overnight lows drop into the teens to 20s each night. A cold front stalled will yield increased clouds Friday and Saturday with otherwise seasonable and dry conditions for the weekend. Come Monday, a low pressure system tracking east from the Great Lakes towards New England will push the associated warm front through the area. A slight chance of precipitation is expected, mainly in the northern portions of the forecast area. Precipitation in the morning may be a rain/snow mix as temperatures rise above freezing before transitioning to all rain in the afternoon. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... VFR conditions will continue through tonight. Gusty northwest winds will continue gradually diminishing. A period of light snow or flurries cannot be ruled out late tonight into Thursday morning (around 8Z through 13Z). This is most likely at DCA, BWI, and MTN. MVFR is possible in some light snow during this time. Any accumulation will be light, but with it being cold it would only take light accumulations for impact. VFR conditions are expected for the rest of Wednesday through Wednesday evening. Another upper-level disturbance may bring a period of light snow or flurries late Wednesday night into Thursday morning. MVFR/IFR vsbys are possible during this time and any light accumulation may have impact due to the cold conditions. VFR conditions are expected as surface high pressure builds over the region Thursday through Saturday. West winds on Friday shift to northwest on Saturday, gusting around 10 knots each afternoon. Light and variable winds are expected overnight. && .MARINE... Winds will continue to gradually diminish over the waters tonight, but an SCA is in effect for all of the waters this evening and for the Chesapeake Bay/lower tidal Potomac River overnight. An SCA is in effect for the waters Wednesday ahead of an approaching cold front, and SCAs will likely be needed Wednesday night as well. The cold front will pass through late Wednesday night into Thursday, and more gusty northwest winds are expected behind the cold front. An SCA will likely be needed for the waters with gusts around 30 knots possible. A brief period of gales can't be ruled out right with frontal passage early Thursday. High pressure will build overhead later Thursday through Saturday. West winds on Friday shift to northwest on Saturday, with winds expected to stay below Small Craft Advisory criteria each day. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Winter Weather Advisory from 4 PM Wednesday to 10 AM EST Thursday for MDZ501. Winter Storm Warning from 4 PM Wednesday to 10 AM EST Thursday for MDZ509-510. VA...Winter Weather Advisory from 4 PM Wednesday to 10 AM EST Thursday for VAZ503. WV...Winter Storm Warning from 4 PM Wednesday to 10 AM EST Thursday for WVZ501-503-505. MARINE...Small Craft Advisory until 6 PM EST Wednesday for ANZ530>534- 537>543. Small Craft Advisory until 9 PM EST this evening for ANZ535- 536. Small Craft Advisory from 10 AM to 6 PM EST Wednesday for ANZ535-536. && $$ SYNOPSIS...BJL/DHOF NEAR TERM...DHOF/CJL SHORT TERM...BJL/DHOF/CJL LONG TERM...AVS AVIATION...BJL/AVS/DHOF/CJL MARINE...BJL/AVS/DHOF/CJL