


Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
591 FXUS61 KLWX 050759 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 359 AM EDT Sat Jul 5 2025 .SYNOPSIS... High pressure will move off the Mid Atlantic coast through Sunday while low pressure moves toward the southeastern U.S. coast. A cold front will approach from the northwest Monday, before potentially stalling near the area during the middle to latter portions of next week. && .NEAR TERM /THROUGH TONIGHT/... Surface high pressure is moving east from the Mid Atlantic coast this morning while upper ridging expands from the Mississippi Valley. Tropical Depression Three is located east of coastal Georgia. A mixture of radiational fog and firework smoke visibility reductions are noted across the forecast area early this morning. Other than a few of the deeper river valleys in the highlands, dense fog appears unlikely but will continue to monitor. Visibilities will improve after sunrise. With ridging dominating through tonight, dry weather will likely prevail. A few models (e.g., NAM Nest) produce a few showers over the Shenandoah Valley and highlands this afternoon. However, convergence and instability are not as notable as Friday, so have left the forecast dry. Otherwise a mixture of cumulus and cirrus will result in mostly sunny skies. A return to SE/S flow will lead to slight increases in temperature and humidity, but it will remain a seasonable early July day with highs in the mid 80s to around 90. Patchy fog may develop again tonight as lows drop into the 60s to around 70. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... High pressure will move farther off the coast Sunday. The upper ridge axis will gradually shift eastward as well as a shortwave moves toward the Great Lakes Region. The associated cold front may approach Monday but also may remain north of the area. Meanwhile, the shift in the upper level pattern will allow what becomes of TD 3 to start lifting northward. Uncertainty is still fairly high in how this system evolves, so refer to National Hurricane Center products for the latest information. Sunday will likely feature increasing clouds from south to north in association with the tropical system. A few showers or storms could work northward Sunday afternoon into Sunday night, but the bulk of the moisture should remain to the south. Shower and thunderstorm chances will trend upward Monday, but coverage will be highly dependent on the tropical system and whether forcing from the cold front reaches the area. At this juncture, impacts appear to be minimal, but will continue to monitor the rainfall aspect. Temperatures will continue to trend upward slightly, but the amount of cloud cover could make the difference between mid/upper 80s and lower 90s. The more noticeable difference will be the return of muggier dew points, especially by Monday. The increasing moisture will limit lows to the upper 60s and lower 70s. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Precipitation chances increase on Tuesday as a cold front pushes through the forecast area before stalling through the end of the week. Showers and thunderstorms are possible each day with a warm and humid airmass yielding plenty of instability. In addition to the cold front approaching and stalling over the forecast area, another system of note is Tropical Depression 3 located off the Georgia/Florida coast. There remains a good bit of model discrepancy surrounding the low pressure system, although it has the potential to produce heavy rainfall in the area should the track take it northward. We will continue to monitor as it gets closer. Temperatures Tuesday and Wednesday will be in the the 80s to low 90s with higher elevations staying in the upper 70s. Overnight low temperatures will dip into the 60s and 70s. High temperatures cool slightly on in the wake of the cold front. Highs will be in the 80s for most with only isolated locations reaching the 90s Thursday and Friday. Higher elevations will stay in the 70s both days. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... A mixture of radiation fog and particulates from last evening`s fireworks is causing visibility reductions across the area this morning. At this time, dense fog appears unlikely (though IFR conditions are affecting MRB), with visibilities improving after sunrise. Light S to SE winds prevail with few/scattered cumulus developing. Some patchy fog may develop again tonight, but uncertain if it affects any of the TAF sites. VFR conditions prevail Sunday with light south winds. There are some indications of greater fog and/or low cloud coverage Sunday night. Some tropical moisture may move into the area Monday, but coverage of showers, thunderstorms, and low clouds remains uncertain. Sub-VFR conditions are possible Tuesday and Wednesday afternoon as showers and thunderstorms impact the terminals as a cold front approaches and stalls over the forecast area. Winds will be light and variable on Monday and Tuesday before shifting to northwesterly in the wake of the front Tuesday evening. && .MARINE... South to southeast winds should prevail through the weekend as high pressure moves offshore, though local diurnal shifts are possible with the weak pressure gradient. A stronger push of winds Sunday afternoon/evening may result in marginal advisory conditions along the bay. Remnants of Tropical Depression Three may approach the area Monday. While winds will not be an issue, the chance for thunderstorms will increase. Refer to National Hurricane Center products for the latest information on this system. Showers and thunderstorms are possible over the waters as a cold front moves through and stalls over the forecast area. Winds are expected to stay below SCA criteria both Tuesday and Wednesday, although SMWs are possible during afternoon showers and thunderstorms. && .TIDES/COASTAL FLOODING... Southerly winds will result in slight increases in water level anomalies over the next several days. While flooding is unlikely for most areas, Annapolis may near minor flood thresholds during the overnight high tides. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...ADS NEAR TERM...ADS SHORT TERM...ADS LONG TERM...AVS AVIATION...ADS/AVS MARINE...ADS/AVS TIDES/COASTAL FLOODING...ADS