738 FXUS61 KLWX 310824 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 324 AM EST Wed Dec 31 2025 .SYNOPSIS... A reinforcing shot of cold air, wind, and mountain snow look to accompany an area of low pressure and it's associated cold front later today through Thursday morning. High pressure briefly returns from the west Friday before another area of low pressure passes to the south Saturday. High pressure returns briefly Sunday with another clipper type system set to push across the area early next week. && .NEAR TERM /THROUGH TONIGHT/... Still monitoring the progression of a weak northern stream disturbance cutting across the area this morning. A few light precipitation echoes have been noted on radar (as of 315am) over the Alleghenies and Catoctins as well as along/east of I-95. Locations west of the Alleghenies have seen some light snow per recent observations and cameras in the area. Of course this is where the better moisture/lift can be found given the source of moisture being pulled south and east from Lake Erie/Michigan. This will lead to perhaps a dusting to up to 2 inches of snow, especially along favored western facing ridges (Keysers Ridge, Backbone Mountain, Spruce Knob, etc.) heading into the morning commute. Expect slick travel west of Frostburg along I-68/US-40 as well as along US-48 west of Moorefield, WV, US-33 west of Franklin, WV, and US-219 from the PA/MD line to WV line. Further east toward the metros, moisture remains limited. Even with that said, hi-res guidance continues to show upward motion in the mid-levels that is aligned with saturation and the DGZ. This will play tug of war with the dry air at the surface to produce either flurries or perhaps a light period of snow at or around sunrise (4am- 8am) across northeast portions of MD and down through the Baltimore/DC metros areas. Have maintained at least a 20 to 30% chance of a light coating of snow in these areas given the consistency amongst the hi-res guidance. The wildcard remains the dry the air. If there is too much we are looking at flurries in the aforementioned areas above and no impact to the commute. If there is less dry air (at the surface) we could be looking at a quick 2-4 hour window of light snow (less than 0.5 inch) that will stick to the cold pavement and create impact for the commute. A Special Weather Statement was issued for this threat, highlighting the potential impacts on the morning commute. Any light snow will diminish over the entirety of the area by mid to late morning with a lull expected before the main upper level disturbance and it's reinforcing cold front swing through tonight into Thursday morning. This system will be much stronger bringing with it renewed cold temperatures, wind, and impactful mountain snow. A strong west to northwest wind will lead to better upslope enhancement over the mountains with perhaps some spillover in the form of snow squalls, showers, and flurries east of the mountains late tonight into early Thursday morning. Most hi-res guidance continues to hint at this potential with some impacts north of I- 66/US-50. Something that will continue to monitor given the timing with late New Year's Eve/early New Year's Day festivities. Winter Storm Warnings remain 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 (15-17:1 increasing to 20 to 22:1) suggest that significant accumulation is possible (around 6- 10"+ 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 10 inches +, with the areas in advisories between 2 and 4 inches. The confidence for accumulation east of the mountains still remains in question. If the hi-res solutions are correct, a light dusting of snow is possible north of the I-66/US-50 corridor. This is where most of the guidance illustrates a narrow band of snow pushing through. Slightly higher confidence would be given to areas north of I-70 since the better forcing and snow squall parameter values are along and north of the PA/MD line. Something that will continue to monitor as the day progresses. Highs today will range from the mid 20s over the Alleghenies to mid 30s and low 40s further east. Wind chills will make it feel like the single digits over the mountains with upper 20s and low 30s east. Gusts of 20 to 25 mph can be expected later this morning and into the afternoon. Lows tonight will fall back into the low teens over the mountains with low to mid 20s elsewhere across the region. Wind chills will fall back below zero over the mountains with low teens further east. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... Accumulating upslope mountain snow showers will likely linger along and west of the Alleghenies through Thursday midday. Northwest flow will gradually diminish as the moisture source is choked off given brief high pressure building in from the Ohio River Valley. The high will gradually settle overhead Thursday night into Friday bringing drier and colder conditions. Winds will also decrease during this time as the gradient finally relaxes heading into late week. Expect highs Thursday in the teens over the mountains with upper 20s and low 30s, along and north of I-66/US-50. Locations south will be a touch warmer with highs in the mid 30s. Northwest winds will gusts 20 to 30 mph with (35 to 45 mph gusts mtns.) Thursday morning into Thursday evening. This will yield single digit to below zero wind chills over the mountains with teens and 20s for feels like numbers east. Lows Thursday night will fall back into the teens and 20s under clearing skies and decreasing winds. High pressure will shift off the southern Delmarva coast Friday morning into Friday afternoon. Meanwhile, stalled front to the south will try to lift back to the north Friday afternoon into early Saturday. This system will lead to extra cloud cover, mainly south of I-66/US-50 and down around I-64. Any precipitation chances will remain south of US-460 in VA. The front flops back to the south Saturday morning. Highs Friday will range from the upper 20s and low 30s over the mountains to upper 30s and low to mid 40s east. Lows Friday night will fall back into the upper teens over the mountains with low to mid 20s east. && .LONG TERM /SATURDAY THROUGH TUESDAY/... A large area of below average heights encompasses eastern Canada while a series of shortwaves traverse across northeastern U.S. Within the southern stream, a progressive wave crosses through the Mid-South on Saturday. However, any precipitation accompanying this feature should stay down over the southeastern U.S. Otherwise, a brunt of the forcing from the northern stream impulses stays off to the north. Additionally, there will not be a whole lot of moisture to work with. Thus, any precipitation chances are quite low for this weekend. High pressure largely remains in charge with daily highs in the mid 30s to mid 40s, with upper 20s to mid 30s in the mountains. At night, most can expect low temperatures down into the upper teens to mid 20s. Heading into the first full work week of 2026, the next frontal system is expected to approach from the west. Height falls are quite weak which will limit the degree of forcing aloft. Any precipitation chances are largely capped in the 20 to 30 percent range and focused along the Alleghenies as a rain/snow mix. Ensemble temperatures show a gradual uptick in numbers heading into early next week. By Tuesday, most locations rise back into the mid/upper 40s, with some low 50s south of I-66 in Virginia and across the Shenandoah Valley. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... Outside of a brief period of light flurries or snow showers within the corridor 9-13z/4am-8am this morning VFR conditions look to prevail at all terminals through this evening. Highest confidence for light snow/flurries would be at BWI, DCA, and MTN. If light snow were to occur, impacts are likely due to the cold surface temperatures. Besides the snow expect wind gusts of 15 to 25 kts at times later this morning and into the afternoon. Skies will be SCT- BKN as strato/alto cumulus rolling off the mountains. An additional wave of low pressure and reinforcing cold front look to track across the region late tonight into Thursday morning. This may bring an additional period of light flurries or snow showers to the corridor between 07z-12z/2am-7am Thursday. MVFR/IFR vsbys are possible during this time and any light accumulation may have impact due to the cold conditions. Confidence here is low given the limited moisture east of the mountains. Something that will have to monitor given hi-res guidance suggesting the potential for light snow at BWI, MTN, IAD, MRB, HGR, and DCA during the time window above. Any accumulation would be light and likely to occur within a 1-2 hour time window. With this band of snow and the front coming through early Thursday morning will come another round of wind. Expect gusts of 20 to 25 kts Thursday morning into Thursday evening. Winds will gradually diminish Thursday night as high pressure builds back into the region. VFR conditions return Thursday afternoon through Friday as high pressure builds back into the region. Winds will shift from the northwest Thursday to the west Friday. Gusts of 10 to 15 kts Thursday evening and night will decrease to less than 10 kts Friday. VFR conditions are expected for all terminals this weekend with weak high pressure moving in from the west. Winds should largely meander between north to northwesterly. Although gradients are on the weaker side, some afternoon gusts up to 15 knots are possible on Sunday. && .MARINE... SCA conditions will continue over the open waters of the bay and lower tidal Potomac through early this morning. Expect a brief lull in the winds this morning with SCA conditions returning for all waters late morning into the afternoon as a reinforcing cold front approaches the waters. The cold front will pass through late Wednesday night into Thursday, and more gusty northwest winds are expected behind the cold front. SCAs have been issued for Thursday with gusts of 25 to 30 kts expected across the waters in the wake of the departing cold frontal boundary. A brief period of gales can't be ruled out right with frontal passage early Thursday morning. High pressure will lead to diminishing winds late Thursday night into Friday. Sub-SCA level conditions are expected at this time. A general area of high pressure across the waters will favor lighter winds throughout the weekend. Gusts should top around 10 knots or so, with winds mainly out of the north to northwest. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Small Craft Advisory until 6 PM EST this evening for MDZ008. Winter Weather Advisory from 4 PM this afternoon to 10 AM EST Thursday for MDZ501. Winter Storm Warning from 4 PM this afternoon to 10 AM EST Thursday for MDZ509-510. VA...Winter Weather Advisory from 4 PM this afternoon to 10 AM EST Thursday for VAZ503. WV...Winter Storm Warning from 4 PM this afternoon to 10 AM EST Thursday for WVZ501-503-505. MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ530>534-537>543. Small Craft Advisory from 10 AM this morning to 6 PM EST this evening for ANZ535-536. && $$ SYNOPSIS...EST NEAR TERM...DHOF/EST SHORT TERM...EST LONG TERM...BRO AVIATION...BRO/DHOF/EST MARINE...BRO/DHOF/EST