Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
846 FXUS61 KLWX 140146 AAA AFDLWX Area Forecast Discussion...UPDATED National Weather Service Baltimore MD/Washington DC 946 PM EDT Wed Aug 13 2025 .SYNOPSIS... A cold front will approach the area Thursday afternoon before shifting south Friday. The heat returns Sunday and Monday ahead of another cold front set to pass through. Cooler temperatures with Canadian high pressure by the middle and end of next week. && .NEAR TERM /THROUGH THURSDAY/... Showers have mostly dissipated. Mostly clear tonight, except for high clouds. Areas of low clouds are possible over the mountains. Previous afd... A residual shower or two cannot be ruled out overnight with areas of fog late. Highs today will push into the mid to upper 80s due to the extra cloud cover and multiple rounds of showers. Some locations may pop 90 degrees depending on how much solar insolation can occur. Lows tonight will fall back into the upper 60s and low 70s. Dewpoints will remain in the 70s allowing the muggy feel to continue at least until the end of the workweek. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... Shower and thunderstorm chances continue Thursday as upper level troughing over Canada pushes a weak cold front through the forecast area. Hot and humid conditions are expected as high temperatures rise into the upper 80s to low 90s for most. Those at higher elevations will stay in the upper 70s. Conditions dry out overnight with low temperatures dropping into the mid 60s to low 70s across the area. On Friday, precipitation chances linger in the southern portions of the forecast area as the aforementioned front stalls to the south. Temperatures will be slightly cooler in the wake of the front, with highs staying in the 80s for most. Surface high pressure builds over Canada, extending towards the mid-atlantic with dry conditions expected in the northern portions of the forecast area. Overnight low temperatures will be in the 60s west of the Blue Ridge and low 70s east of the Blue Ridge. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Not much of a change in the overall pattern for the upcoming weekend and early next week. The subtropical ridge over the southeastern U.S should strengthen/build with 500 mb heights hovering between 590-594 decameters per 12z GEFS/EPS output. Meanwhile, a weakening cold front will dissipate across central/southern portions of the forecast area Saturday. Humidity will lower in the wake of the front with perhaps a few spotty showers/t-storms tied to the initiation the bay/river breeze as well as terrain. High temperatures Saturday should push into the mid 80s to low 90s, with mountain locations in the mid 70s to low 80s. Low temperatures will fall into the low to mid 60s over the mountains with mid 60s to low 70s further east toward the Baltimore/Washington DC metro areas. More heat and humidity Sunday ahead of a encroaching cold frontal boundary from the Great Lakes and northern Ohio River Valley. High temperatures will climb back into the low to mid 90s for most with heat index values hovering between 95-100 degrees. A few spotty showers or t-storms cannot be ruled out especially over the mountains and northern portions of the forecast area given the amplified northern stream. Slightly higher chances for shower and thunderstorms exists for the early and middle part of next week. Current 12z deterministic and ensemble guidance, continues to show a fairly amplified northern stream. Ridging high pressure remains over the southeastern U.S with a secondary ridge over central and eastern Canada. Caught in between the two is a decent frontal zone extending over the northern tier of the U.S. Within this frontal zone will be a series of fronts that will drop south from the Great Lakes/Ohio River Valley Monday through Wednesday next week. The first front looks to cross the area late Sunday before washing out over the central and southern part of the forecast area Monday. Another front will follow Tuesday into midweek delivering a cooldown for the latter half of next week. With the multiple fronts crossing the area expect an uptick of shower and thunderstorm chances mainly during the afternoon/evening hours. Any storms that we do see this weekend into next week will be capable of producing locally heavy rainfall, frequent lightning, and gusty winds. Highest coverage of storms appears to be on Tuesday as the ridge buckles and stronger of the two fronts passes through. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Shower and thunderstorm chances continue on Thursday as a cold front pushes across the area. Brief restrictions are possible across all terminals in the afternoon. On Friday, the cold front stalls to the south with precipitation chances lingering for KCHO. Otherwise, VFR conditions are expected. Northwest winds blowing 5 to 10 knots on Thursday shift to northeasterly Friday, blowing around 5 knots. Light winds are expected both nights. Convection overall will be fairly spotty this weekend given the strengthening subtropical ridge overhead. VFR conditions should prevail outside of any temporary sub-VFR reductions from spotty storms in the afternoon. Highest confidence for this will be at terminals near the terrain. Winds will be out of the east and southeast Saturday at less than 15 kts. Winds will switch back south and southwest Sunday before switching to the north and northeast Monday. A stronger cold front looks to cross Tuesday into Wednesday next week. && .MARINE... Winds remain below SCA criteria Thursday and Friday with no marine hazards expected. SMWs may be needed again Thursday afternoon as an isolated thunderstorm is possible over the waters as a cold front moves over the forecast area. Winds remain light on Friday as the aforementioned front stalls to the south. Sub-SCA level winds will continue through the period. Winds will remain light out of the east and southeast Friday and Saturday at less than 15 kts. This is due in part to a dissipating frontal boundary over the region. Winds will switch to the south and southwest Sunday and Monday at less than 15 kts. Some southerly channeling remains possible Sunday into Monday over the open waters, but overall confidence is low. && .TIDES/COASTAL FLOODING... Elevated tidal anomalies look to continue through the end of the week given the recent full moon and light winds. While minor tidal flooding is not expected, some cycles could go into Action stage during the high astronomical tides (especially at Annapolis and perhaps Dahlgren/Alexandria). && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...AVS LONG TERM...EST AVIATION...AVS/LFR MARINE...AVS/LFR TIDES/COASTAL FLOODING...