


Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
065 FXUS61 KLWX 070054 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 854 PM EDT Tue May 6 2025 .SYNOPSIS... An upper-level disturbance passes through tonight. High pressure will follow briefly for Wednesday. A stronger cold front will approach Thursday before passing through Thursday night into Friday while low pressure develops along the boundary. High pressure will likely follow for the upcoming weekend. && .NEAR TERM /THROUGH WEDNESDAY/... A closed upper-level low continues to shift northeast away from the area this evening into tonight. On the backside of the low, a broad area of light stratiform rain/showers has moved into the Potomac Highlands and Alleghenies. This rain could push a bit east of the Blue Ridge into the MD Piedmont and Northern VA areas overnight. Otherwise, those south of I-66 and in the central Shenandoah Valley remain mostly dry. A rumble of thunder cannot be ruled out, but little CAPE is evident in model soundings above -10C. Lows tonight settle in the 50s for most areas, with 40s in the Alleghenies. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... The upper-level continue to move away from the area Wednesday, and the combination of rising heights, westerly flow, and weak high pressure will allow for dry conditions for most areas along with some sunshine. Highs will range from the 60s in the mountains to the 70s/near 80 for most other locations. Dry conditions will most likely persist for Wednesday night as well. A stronger cold front will approach from the northwest Thursday before passing trough Thursday night into Friday. There is still some uncertainty to the timing of this system and strength. Guidance shows another cutoff upper-level low developing, and this will likely cause surface low pressure to develop along the cold front. The exact position of where this upper-level low develops will dictate how strong the surface low is along the front, and consequently how quickly the dry air behind the front can move into the area. As of now, it looks like showers are likely with possible thunderstorms later Thursday into Thursday evening. Additional showers are possible overnight Thursday, depending on the speed of the cold front. && .LONG TERM /FRIDAY THROUGH TUESDAY/... A blocky pattern remains in place into the early part of next week, meaning that there could be some predictability issues. On Friday, a cold front will be near or southeast of the area. A northern stream trough will be closing off into an upper low. Although there is a trend toward a low developing along or off the coast in response to the trough, there is still considerable uncertainty in its placement. This will determine whether there are any lingering rain chances on Friday. However, confidence is higher that temperatures will fall below normal for Friday and Friday night. As long as the closed low remains to the east, high pressure will likely provide dry weather and a warming trend for the weekend. A decaying cold front may drop toward the area Sunday but would have negligible effects on sensible weather. High pressure may stick around into Monday, but moisture originating from a different closed low over the deep south may start to work northward at some point next week. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... Sporadic showers with some steady light rain likely at MRB late this evening into tonight, and that could possibly reach IAD for a few hours as well. Otherwise, expect dry/VFR conditions to persist. High pressure brings VFR conditions for Wednesday through Thursday morning, but additional showers are likely with possible thunderstorms Thursday afternoon into Thursday night with possible sub-VFR conditions. Sub-VFR ceilings and showers may persist into Friday depending on the position of developing low pressure off the coast. VFR conditions will follow as high pressure builds toward the area Saturday. && .MARINE... Winds quickly diminished below SCA levels early this evening, and will remain so through tonight. Weak high pressure will build overhead for Wednesday into early Thursday. However, more showers are likely with possible thunderstorms Thursday afternoon into Thursday night. As low pressure moves off the coast, winds will be north to northwest Friday into Saturday. SCAs may be needed Friday into Friday night, especially along the bay where the northerly winds could channel. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...BJL NEAR TERM...KRR SHORT TERM...BJL LONG TERM...ADS AVIATION...KRR/Johnson/BJL/ADS MARINE...KRR/Johnson/BJL/ADS