Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
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815 FXUS61 KLWX 060051 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 851 PM EDT Sat Sep 5 2026 .WHAT HAS CHANGED... No major changes were made to the latest forecast package. && .KEY MESSAGES... - 1) Isolated showers linger through the evening, but there will be no severe weather threat. - 2) Drier conditions with seasonable temperatures and lower humidity Sunday into early next week. - 3) Shower and thunderstorm chances return by mid week. && .DISCUSSION... KEY MESSAGE 1...Isolated showers linger through the evening, but there will be no severe weather threat. The primary cold front is currently nosing southward while moving into northern sections of North Carolina. Despite the post-frontal air mass, humidity levels have not fully dropped off yet with current dew points in the mid 60s to low 70s. Compared the 00Z IAD sounding from the one this morning showed much of the drying occurring in the 700-mb and above layer. Looking on radar, most afternoon activity has waned with the loss of daytime heating. However, some residual isolated showers persist, mainly along I-64 and up toward the Shenandoah Valley. These too should dissipate in time with diminishing levels of instability. Low temperatures will drop several degrees from previous nights into the 60s for most, even mid 50s in the mountains. KEY MESSAGE 2...Drier conditions with seasonable temperatures and lower humidity Sunday into early next week. Broad high pressure over the Great Lakes will track over the Mid-Atlantic Sunday into Monday, with accompanying mid-level dry air that will bring down humidity and t-storm chances. Daily highs drop into the low 80s, along with drier dewpoints in the mid to upper 50s. Overnight lows in the 50s and low 60s. Surface high pressure begins to transition south of the Mid-Atlantic on Tuesday as upper level ridging builds over the Southeast. Temperatures likely begin to creep up again during this time, accompanied by increasing humidity as mid-level dry air tracks south of the region with more humid air coming in from the north. This will correspond with strong upper-level trough forming over Quebec around midweek, with an accompanying cold front tracking across the East Coast sometime between Wednesday and Thursday. This could create some chances for precipitation over the region, with some indicators for low-end instability over the area as this mid-level moisture tracks southeast. Severe probabilities look low at this time, but a few thunderstorms are not completely out of the question as this front moves through. Looking towards late next week, temperatures likely drop again in the wake of this cold front Friday as it tracks to the south. KEY MESSAGE 3...Shower and thunderstorm chances return by mid week. Entering into the later half of next week, southerly return flow from a high pressure system just off the Mid-Atlatic coast drives warm, moist air into our region. Models depict a surface low deepening over Quebec and advancing a corresponding cold front through our region sometime late next week. There is still a quite a bit of uncertainty associated with the arrival of this boundary to our region, with its arrival ranging between Wednesday and Thursday. A bove-normal high temperatures and dew points out ahead of this boundary could potentially destabilize the atmosphere and lead to showers and thunderstorms late next week. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... A few showers may linger into the night at KCHO, but these will be more or less off and on. VFR conditions should persist Sunday through Wednesday evening. Flight categories could deteriorate with showers and thunderstorms returning on Thursday. Light southerly winds on Wednesday shift northwesterly and strengthen by Thursday. && .MARINE... No marine hazards are expected through the holiday weekend. Generally light flow is expected, though onshore gusts could approach marginal SCA levels late Sunday afternoon. Northeasterly winds Monday shift southerly on Tuesday. Winds stay below 15 knots through Monday and Tuesday. Winds could increase to SCA levels on Wednesday into Thursday ahead of an incoming cold front. && .TIDES/COASTAL FLOODING... Tidal anomalies remain elevated over the next several days due to an onshore flow. Minor tidal flooding is possible at Annapolis, and could also be possible in the other sensitive tidal locations in the northern Chesapeake Bay. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ DISCUSSION...BRO/CJL/KVH AVIATION...BRO/CJL/KVH MARINE...KVH