


Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
063 FXUS61 KLWX 271839 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 239 PM EDT Wed Aug 27 2025 .SYNOPSIS... Surface high pressure will bring dry conditions through Thursday with cooler than average temperatures expected. A cold front will cross the region Friday bringing passing clouds and perhaps a few spotty showers. High pressure wedges in for the weekend into early next week with a passing shower or two over the central Blue Ridge as onshore upslope flow increases. Low pressure approaches from the south by the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... Scattered (east) to broken (west) cumulus were bubbling across the area as of mid afternoon as high pressure builds in. Modest northwest downsloping flow gusting 15 to 25 mph is helping temperatures rise into the 70s. Winds will subside this evening with the loss of daytime mixing. As the high moves overhead, an ideal setup for radiational cooling will take hold. This should allow sheltered high elevation valleys to drop into the 30s or even a touch colder in very isolated spots, with 40s and 50s elsewhere (except around 60 in the major city centers). && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... High pressure will continue to build across the area Thursday. Cooler than average temperatures and dry conditions will continue through the day. A shortwave trough and its affiliated surface cold front will approach the region Thursday night. Isolated to scattered showers and sprinkles could evolve Thursday night. Highs Thursday will be in the 60s in the mountains, and middle to upper 70s elsewhere to the east. Lows Thursday night will be in the upper 40s to lower 50s in the mountains, and upper 50s to lower 60s to the east. A cold front pushes across the region on Friday into Friday evening. A couple additional showers could accompany the front during this period but coverage looks widely scattered at best. Highs Friday will be similar to Thursday, if not a few degrees milder. Temperatures Friday night will become cooler than Thursday night with cool air advection behind the front. Lows Friday night could get as cold as the upper 30s in the mountains. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Overall the forecast remains dry with cooler than normal temperatures expected to continue throughout period. Expect light north to northeasterly flow Saturday into Sunday with light onshore flow early next week. This is in association with building high pressure over the Great Lakes region that will gradually wedge south Monday into Tuesday. This high pressure system will eventually drift east into the interior Northeast and toward northern New England Wednesday through Friday. Meanwhile, an area of low pressure will remain to our south along a stalled boundary over the southeast U.S. The progression of this low pressure system to the north will be halted by the wedge through at least Tuesday before an advancement north and east along the coastal Carolinas by the middle and end of next week. As of now, little to no impact is expected from this system in our area outside of some shower activity mainly along and east of I-95 Wednesday and Thursday next week. A strong cold front will eject out of the northern Plains and Upper Midwest late Wednesday into Thursday before crossing late next week. This will lead to our next substantial rain chances areawide within the long term period. Temperatures will remain cooler than normal throughout the weekend into much next week. Expect highs in the mid to upper 70s and lows in the 50s. Mountain locations will be a touch cooler in the upper 60s and low 70s with lows in the 40s and 50s. Increased onshore flow from wedging high pressure will further confidence for cooler than normal temperatures Sunday through Tuesday next week. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... VFR conditions are expected through Friday night. Some daytime stratocumulus clouds are expected, with some high clouds possible tonight. Some increasing clouds are likely on Thursday ahead of a cold front, then along the cold front Thursday night. A shower could occur Thursday night, but not much more. A shower is possible in spots Friday; otherwise, it will be drier behind the passing front Friday night. VFR conditions are expected to continue through the weekend into early next week with wedging high pressure nearby. There are some hints at the potential for sub-VFR CIGs during the late evening and early morning hours Saturday through Tuesday mainly at terminals south of KCBE/KMRB and west of KCHO. This is due in part to increased onshore easterly upslope flow. && .MARINE... Winds diminish this evening and remain light through Thursday morning. Another period of SCA conditions is possible (southerly channeling) Thursday afternoon into Friday morning. Another period of SCA conditions may be possible Friday night behind a cold front, but current guidance looks somewhat marginal. No marine hazards are expected this weekend. Sub-SCA level north to northeast winds are expected throughout the weekend as high pressure builds from the north. Sub-SCA level winds continue Monday through Wednesday as high pressure wedges down the eastern face of the Appalachian Mountains. && .TIDES/COASTAL FLOODING... Southerly flow ahead of a cold front may drive water levels close to minor flooding at Annapolis Thursday evening. The flow should be brief enough to preclude flooding elsewhere, though the typically more vulnerable spots will have to be monitored. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...DHOF/EST NEAR TERM...DHOF SHORT TERM...DHOF/KLW LONG TERM...EST AVIATION...DHOF/EST MARINE...DHOF/EST TIDES/COASTAL FLOODING...DHOF