169 FXUS61 KLWX 271923 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 323 PM EDT Sun Jul 27 2025 .SYNOPSIS... A warm front lifts north of the forecast area this afternoon as weak surface high pressure builds to the southwest through Tuesday. A cold front approaches from the Great Lakes Wednesday before moving through the region on Thursday, bringing a noticeable change in airmass for the weekend. && .NEAR TERM /THROUGH TONIGHT/... Showers and thunderstorms are currently tracking across the forecast area with additional storms moving in from the west. Strong to severe thunderstorms have been and will continue to be capable of producing damaging winds, torrential rainfall, and frequent lightning. As the second round of storms move towards the metros, areas that saw rain earlier today will be vulnerable to flash flooding. PWATS nearing or exceeding 2" will lead to heavy rainfall, mainly east of the Blue Ridge. Precipitation will move out of the area this evening with dry conditions expected overnight. Low temperatures will be in the 70s for most with higher elevations dipping in the 60s. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... Monday and Tuesday will offer a brief respite from the daily shower and thunderstorm chances. Weak high pressure building to the southwest accompanied by weak upper level ridging will yield primarily dry conditions. That being said, there is a slight chance to a chance of precipitation Monday afternoon west of the Blue Ridge as shortwave energy passes to the north. Areas along and east of the Blue Ridge will remain dry throughout the day. Conditions remain dry throughout the day Tuesday with surface high pressure continuing to build to the south. Warm and humid conditions continue Monday and Tuesday with high temperatures in the upper 80s to 90s both days. Higher elevations will stay in the low to mid 80s. Humid conditions will yield heat index values of 100 to 105 at lower elevations. Overnight low temperatures will be in the 70s for most with those along and west of the Alleghenies dipping into the 60s. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Hot and humid conditions will continue Wednesday with highs reaching the mid to perhaps upper 90s. While dew points may mix down a bit, heat index values of 100-110 will remain possible. A shortwave trough moving through the Great Lakes will help push a cold front southward, but it may not reach the area until Wednesday night. Thus there is some uncertainty with the coverage of thunderstorms during the day, as there may just be some remnant activity that settles in overnight. The front will be nearly overhead Thursday, and a wave of low pressure may track along it. This will likely result in greater coverage of precipitation. While there may be a risk for some stronger storms either day, a heavy rain/flood threat may evolve Thursday as convection potentially trains near the front in a moisture rich airmass. While still muggy, heat should be less of a concern Thursday with more clouds and the front nearby. The frontal zone may remain close enough by on Friday for additional chances of showers, although it will be cooler and cloudier and the main boundary will be well to the south. Over the weekend, conditions should improve as strong high pressure builds to the north. Temperatures will drop below normal, and dew points will be more comfortable in the 50s to around 60. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... Showers and thunderstorms are currently moving southeast of the terminals with visible satellite as of 2:30PM showing cumulus clouds developing in their wake. While the strongest of the expected convection today has moved through, pulse storms are possible again through the evening. Confidence is lower on location and timing, so kept it at a prob30. For KMRB and KCHO, chances for showers and thunderstorms are highest. Within strong to severe thunderstorms, damaging wind gusts, torrential rainfall, and frequent lightning are the primary hazards possible across all terminals. Thunderstorm chances diminish overnight with the loss of daytime heating with VFR conditions expected. Winds stay out of the west, blowing 5 to 10 knots before becoming light and variable overnight. Shower and thunderstorm chances remain for KMRB and KCHO on Monday with terminals further east expected to remain dry. Prevailing VFR conditions are forecast across all terminals, although brief periods of flight restrictions are possible during precipitation at KMRB and KCHO. Winds remain out of the north/northwest Monday and Tuesday, blowing around 5 knots before becoming light and variable overnight. A cold front will approach late Wednesday and stall over the area Thursday. Some thunderstorms may reach the area Wednesday, but there will be a greater chance Thursday. Sub-VFR ceilings and lingering showers will be possible Thursday night into Friday. && .MARINE... SMWs will likely be needed this afternoon and into the evening as thunderstorms track across the waters. Strong winds and frequent lightning are the main hazards expected today. Outside of convection, winds stay below SCA criteria with no marine hazards expected. No hazardous marine conditions are expected Monday and Tuesday as winds remain below SCA criteria. Winds remain light, blowing around 5 knots out of the north/northwest both days. Southerly channeling may result in marginal advisory conditions along the bay Wednesday evening. A few thunderstorms are possible as a cold front approaches Wednesday night, with greater potential for thunderstorms Thursday. As the front slowly pushes south, Small Craft Advisories may be needed Friday in northerly flow. && .TIDES/COASTAL FLOODING... Tides remain elevated over the next several high tide cycles, partially due to the recent new moon, and partially due to light flow not really allowing water to exit southward out of the Chesapeake Bay. No areas are forecast to hit minor at this time, but sensitive tidal locations will continue to reach Action Stage during the high tide cycles through mid-week. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...Heat Advisory until 8 PM EDT this evening for DCZ001. MD...Heat Advisory until 8 PM EDT this evening for MDZ013-016>018. VA...Heat Advisory until 8 PM EDT this evening for VAZ037>039-050- 051-053>057-502-527. WV...None. MARINE...None. && $$ SYNOPSIS...AVS NEAR TERM...AVS SHORT TERM...AVS LONG TERM...ADS AVIATION...ADS/AVS/CJL MARINE...ADS/AVS TIDES/COASTAL FLOODING...LWX