


Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
117 FXUS61 KLWX 170133 AAA AFDLWX Area Forecast Discussion...UPDATED National Weather Service Baltimore MD/Washington DC 933 PM EDT Mon Jun 16 2025 .SYNOPSIS... A warm front will lift into the area Tuesday and Wednesday allowing temperatures to rebound while keeping a daily chance for showers and thunderstorms. Severe thunderstorms are possible Thursday into Friday as a strong cold front crosses the region. High pressure returns this weekend with hot and dry conditions expected. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Area will remain wedged overnight with low clouds and drizzle north of the front, particularly along I-95 and showers across the central Shenandoah Valley and portions of the Appalachians. Low clouds with cigs below 500 ft will be common overnight with dense fog at higher elevations. Temperatures will remain steady in the mid to upper 60s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... The stalled frontal boundary south of the area is finally forecast to lift north as a warm front Tuesday morning, then pushing just north of the area Tuesday afternoon. A subtle upper level trough will approach from the Ohio Valley Tuesday, then cross the area on Wednesday. Still, we remain in a moist and unstable airmass south of the warm front through Wednesday. This is going to fuel daily showers and thunderstorms, especially on Wednesday when the upper trough swings through. The risk for severe weather is low, though non-zero as SPC maintains a Marginal Risk (Level 1 out 5) over portions of the Alleghenies and Shenandoah Valley/central Piedmont region for Tuesday. Damaging winds look to be the main threat with storms along with localized flash flooding. Storms should be fairly progressive, but given the antecedent conditions and moist atmosphere at play localized instances of flash flooding cannot be ruled out. For Wednesday, the severe threat looks limited, but depending on the coverage of showers and thunderstorms there could be a lingering flood threat for parts of the area. After several days of well below normal temps we finally return to normal for mid June as highs reach the mid/upper 80s Tuesday, then upper 80s to low 90s on Wednesday. Lows Tuesday night fall back to the upper 60s and low 70s. Fog may be possible during the overnight hours given the very moist airmass overhead and light winds. && .LONG TERM /THURSDAY THROUGH MONDAY/... An upper level trough pivoting across the Great Lakes region will push a potent cold front through the forecast area on Thursday. As high temperatures rise into the low 90s Thursday afternoon, instability increases ahead of the front with showers and thunderstorms expected. Steep low-level lapse rates (7+ C/Km) combined with moderate bulk shear (30-50 kts) lead to some storms being strong to severe. With any severe convection, damaging wind gusts will be the main hazard type. The storm prediction center has the forecast area east of the Allegheny front in a 15% risk for severe weather on Thursday. We will continue to monitor this threat as it gets closer. In the wake of the frontal passage, overnight low temperatures will be in the 60s for most. Surface high pressure builds overhead Friday through the weekend with primarily dry conditions expected each day. High temperatures on Friday will be in the 80s for most with higher elevations staying in the mid to upper 70s. Temperatures gradually warm each day under high pressure with highs on Sunday expected to be in the mid 90s. In addition to warm temperatures, dew points will be in low 70s with apparent temperatures nearing and exceeding 100 degrees possible. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Widespread LIFR CIGs are expected to continue through Tuesday morning across the area with areas of light drizzle dropping visibility to around 2- 3SM. Conditions are expected to improve by early Tuesday afternoon when a warm front lifts north through the area. While VFR conditions return, there could be another round of showers and thunderstorms Tuesday late afternoon to evening. These storms could bring brief periods of sub-VFR conditions. Another round of afternoon to evening showers and thunderstorms are possible on Wednesday. Outside of this activity, VFR conditions are likely to prevail through mid week. Sub-VFR conditions are likely as showers and thunderstorms impact the terminals Thursday afternoon. Reduced CIGs and VSBYs are possible as well as gusty winds. Southwest winds Thursday morning shift to west/northwest behind a cold front moving through the Mid- Atlantic. Winds remain out of the west on Friday. && .MARINE... Winds are forecast to remain below SCA levels through the middle of the week. Though, cannot rule out a few hours each morning of winds occasionally gusting to around 20 knots. A stalled front south of the region will lift north as a warm front on Tuesday. Winds could reach near-SCA levels Wednesday night, mostly in the middle Chesapeake Bay. Rounds of showers and thunderstorms are forecast to move across the waters Tuesday and Wednesday afternoon/evening. These storms likely will pose a threat to mariners from gusty winds and lightning strikes. Thunderstorm activity could linger late in the evening each day. Small Craft Advisory conditions are possible on Thursday as winds gust between 15 and 20 knots. As a cold front approaches and moves across the waters, SMWS are possible during thunderstorms. Winds are expected to remain below SCA criteria on Friday. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && $$ SYNOPSIS...EST NEAR TERM...LFR SHORT TERM...KRR/EST LONG TERM...AVS AVIATION...AVS/LFR MARINE...AVS/LFR