


Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
800 FXUS61 KLWX 111425 AAA AFDLWX Area Forecast Discussion...UPDATED National Weather Service Baltimore MD/Washington DC 1025 AM EDT Fri Jul 11 2025 .SYNOPSIS... A weak front will remain nearby through the weekend with daily showers and thunderstorms expected. A cold front pushes through the forecast area early next week with another front approaching the region by the end of the week. && .NEAR TERM /THROUGH TONIGHT/... 12Z IAD sounding showed that atmosphere has dried out considerably with PWATs nearly half inch lower since 24 hrs ago. Significant drying/warming is also seen in the mid levels on the three GOES WV channels. For today, height rises should keep coverage isolated to widely scattered along the Blue Ridge and Appalachian Mountains. Cell motion will be slow around 5 kt, so some brief heavy rain is possible. Previous afd... Weak upper level troughing shifts offshore throughout the day as a front remains to the north. Upper level ridging slowly builds overhead with temperatures expected to be slightly warmer compared to yesterday. Highs rise into the 80s to low 90s for most with those at higher elevations staying in the 70s. A moist air mass will yield warm dew points with heat indices rising into the mid to upper 90s for most. Warm and moist conditions yield plenty of instability with afternoon showers and thunderstorms expected. Recent model guidance has convective activity primarily staying west of the Blue Ridge, where the Storm Prediction Center has a Marginal risk. Should convection initiate and become strong to severe, damaging wind gusts will be the primary hazard due to conditions favorable for downbursts. Convective activity is expected to dwindle this evening with the loss of daytime heating. Dry conditions and low temperatures in the 60s and 70s are expected across the forecast area. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... Weak high pressure builds to the southwest through the weekend as a low pressure system and associated cold front approach from the central plains. Diurnally driven showers and thunderstorms are expected each afternoon with precipitation chances increasing each day. Despite weak forcing aloft, a warm and moist airmass will lead to plenty of instability across the forecast area. Sunday has the highest chances for strong to severe thunderstorms with the Storm Prediction Center having a Marginal Risk for the forecast area. Damaging wind gusts will be the primary threat due to a threat for downburst within convection. High temperatures over the weekend will be in the upper 80s to low 90s each day with only higher elevations staying in the low 80s. Overnight low temperatures drop into the 60s for most west of the Blue Ridge and low to mid 70s elsewhere. && .LONG TERM /MONDAY THROUGH THURSDAY/... The period begins with a weakening mid-level trough of low pressure over the Great Lakes region, while a cold front approaches from the northwest. Ahead of the cold front, Monday is expected to be an active weather day with high PWATs and moderate CAPE available for numerous thunderstorms. Cloud cover from this convection and the approaching front should limit daytime temperatures to the mid 80s (70s in the mountains), mitigating heat concerns. Despite this reprieve, chances for isolated flash flooding and/or severe weather on Monday will need to be monitored in the coming days. By Tuesday morning, the front is expected to stall across or just south of the area as weak southerly flow around a Bermuda High advects warm, moist air northward into the region. As the week progresses, temperatures should increase to seasonably warm values with most areas seeing low temperatures in the 70s and high temperatures in the mid-upper 80s outside of the highest elevations. Daily chances of showers and thunderstorms are expected, with the highest coverage occurring over the southern and western counties. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... VFR conditions continue through the weekend with the exception of reduced visibilities and ceilings during afternoon showers and thunderstorms. Winds remain out of the south/southeast each day, blowing around 5 knots each afternoon through the weekend. In addition to flight restrictions, gusty winds and lightning are possible during thunderstorms. Monday will likely be the most impactful weather day of the period, with numerous showers and thunderstorms expected near all TAF sites. Brief MVFR conditions are possible with any convection, some of which may be severe. Outside of storms, winds on Monday will be light from the S and SW, becoming N with the passage of a weakening cold front overnight into Tuesday. Tuesday through Thursday will feature light and variable winds, with daily chances for showers and thunderstorms. KCHO and KMRB will have the higher chances for convection each afternoon. && .MARINE... Southerly winds are expected to remain below Small Craft Advisory criteria through the weekend, blowing 5 knots or less. Showers and thunderstorms over the waters are possible each afternoon, leading to a SMW threat, albeit low, each day. Otherwise, no marine hazards are expected. Prevailing winds throughout the week are expected to remain below 10- 15kts, though funneling of southerly winds across the Lower Chesapeake may lead to gustier winds Thursday. Marine hazards are possible with any thunderstorms entering the waters each afternoon and evening. Some storms may be severe on Monday and require SMWs. && .TIDES/COASTAL FLOODING... A prolonged period of southerly winds will lead to elevated tidal anomalies over the weekend. This carries most of the tidal locations into Action stage, particularly during the higher of the two astronomical high tide cycles. Sensitive locations, such as Annapolis, are forecast to hit Minor stage during the high tide cycle Sunday morning. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...AVS NEAR TERM...LFR SHORT TERM...AVS LONG TERM...CPB AVIATION...LFR/CPB MARINE...LFR/CPB TIDES/COASTAL FLOODING...AVS