Area Forecast Discussion
Issued by NWS Sterling, VA
Issued by NWS Sterling, VA
112 FXUS61 KLWX 270142 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 942 PM EDT Sun Jul 26 2026 .WHAT HAS CHANGED... Added more emphasis on the severe threat for the rest of the evening, as it has increased compared to the previous forecast. && .KEY MESSAGES... - Severe storms tonight, drier Monday, then a strong cold front yields a chance at severe weather on Tuesday. - Drier conditions return mid to late week. && .DISCUSSION... KEY MESSAGE 1...Severe storms tonight, drier Monday, then a strong cold front yields a chance at severe weather on Tuesday. Current water-vapor satellite imagery and the 00z upper-air maps from from the evening balloon launches depict a potent shortwave diving through the region from NW to SE this evening. With a fair amount of instability still left (1000-1500 SBCAPE), this is sparking a few storms. With mid-level lapse rates in the 6-7 C/km range, 30-40 kts of 0-6 km shear, and cold advection occurring at 500mb, a decent hail setup is taking place right now. Central VA will see the best chance for severe hail, as shear drops off markedly to the NW, as does the instability. A few severe thunderstorms have already occurred, and we could see a few more before the night is done. Can`t even rule out a few 60 mph wind gusts with DCAPE values in the 600-800 J/kg range, which is sufficient for some severe downdrafts. Warmer and slightly more unstable conditions are expected Monday, but shortwave ridging aloft may limit thunderstorm coverage. Overall, it looks like less coverage Monday afternoon than today. A deepening shortwave-trough will drop from the eastern Great Lakes into our area Tue afternoon pushing a strong cold front through the area Tue evening. Strong height falls coupled with strengthening winds aloft will lead to greater thunderstorm coverage and storm organization with a much greater risk of severe thunderstorms. Damaging wind gusts appear to be primary risk due to expected fast storm motions, but isolated tornadoes can`t never be ruled out in NW flow. Convection should start exiting the area quickly after 00Z Wed. One caveat is potential for showers and thunderstorms early Tue morning, which may leave behind plenty of clouds and limit instability through the day Tue. KEY MESSAGE 2...Drier conditions return mid to late week. In the wake of Tuesday`s frontal boundary, the associated low will slowly meander towards the northeast over the next couple of days. This should reduce rain chances overall, but spotty showers and thunderstorms remain possible as this low slowly slides offshore of New England late in the week. High pressure moves in overhead towards the end of the week bringing drier air and similar conditions overall as the week prior, with highs in the low to mid 80s. Heading into next weekend, a broad area of low pressure begins to form over the Midwest and track eastward. As temperatures gradually rise towards more normal July averages, this could bring additional shower and thunderstorm chances to the region. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... A few thunderstorms have developed this evening, as was expected, primarily affecting areas south of CHO at the moment. A few pop-up showers can be seen developing along the Blue Ridge now, which could impact IAD and DCA in the coming hours if they continue to develop. Storms could bring some gusty winds, frequent cloud-to-ground lightning, and even some small hail. Less coverage is expected Monday. Severe thunderstorms are likely Tue afternoon with damaging wind gusts and temporary flight restrictions. Prevailing VFR conditions are anticipated the second half of the week. Northwest winds could produce gusts up to 25 kts on Wednesday before diminishing some overnight. && .MARINE... A few storms over the Blue Ridge currently could make it to the waters later this evening. However, the threat for hazardous condtions is much lower the further north and east you go in the forecast area, as shear and instability drop off markedly. Still, can`t rule out a showers over the waters this evening, potentially necessitating an MWS for 20-30 mph gusts and perhaps small hail. Isolated thunderstorms are possible Monday, but upper-level ridging should minimize that threat. SCA conditions are likely Monday afternoon through the middle of the week. Numerous to widespread thunderstorms Tue afternoon which may require SMWs. Strong wind gusts greater than 50 knots, frequent lightning, and hail will all be threats to boaters during this time. SCA conditions could persist through Thursday afternoon before winds diminish overall. Southwest winds shift northwest on Wednesday. && .TIDES/COASTAL FLOODING... Coastal FLood Advisory in effect for Anne Arundel County for the early Monday morning high tide. Strengthening southerly flow combined with a near Full Moon will lead to minor coastal flooding around the time of high tides the next several mornings. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...Coastal Flood Advisory from 2 AM to 8 AM EDT Monday for MDZ014. VA...None. WV...None. MARINE...None. && $$ DISCUSSION...LFR/DHOF/CJL AVIATION...LFR/DHOF/CJL MARINE...LFR/DHOF/CJL