Area Forecast Discussion
Issued by NWS Sterling, VA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KLWX 081425 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1025 AM EDT Thu Jun 8 2023 .SYNOPSIS... An upper low will continue to circulate to our north through Friday, before progressing offshore on Saturday. An area of low pressure will approach the area from the Great Lakes early next week. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
1030 AM Update: Thick smoke has continued to build into portions of the area this morning, with updates in Air Quality Alerts for the District of Columbia as the AQI`s continue to increase (>325 in localized areas). A few showers and thunderstorms have developed across the far SE areas of our northern VA counties and into southern MD. These storms should be remain below severe criteria, while bringing some gusty winds of 15-20 knots intermittently over the next couple of hours before dissipating. Smoke should improve heading into the afternoon hours from north to south but is expected to at least linger into Friday. Previous Discussion Follows: An upper low will continue to circulate to our north across Upstate NY/New England today. Meanwhile, a shortwave disturbance will rotate through the base of the upper low`s circulation, tracking across the southern half of Virginia this morning into the early afternoon hours. In response, surface convergence is expected to be on the increase from the Fredericksburg area to southern Maryland this morning. Around 500-1000 J/kg of CAPE is expected to build across southern Maryland this morning in response to daytime heating. A few showers are already present in this area (as of 3 AM), but further development of showers and thunderstorms is expected late this morning into very early this afternoon. These showers and storms should progress off to the east by mid- late afternoon as the aforementioned shortwave passes off to our east. Elsewhere, dry conditions are expected today. Temperatures will run a bit below normal, with mid to upper 70s common (upper 60s in the mountains). The other main story today will be the continued presence of wildfire smoke. A plume of very thick smoke is descending down from the north in northerly flow this morning. Visibilities have dropped to 1.5-3 miles across northern Maryland. This thick smoke is expected to continue to progress southward over the next several hours. Gradual improvement may occur during the afternoon hours as winds turn northwesterly and deeper mixing ensues. Yet another plume of smoke may descend down into the area tonight. Please refer to airnow.gov or local environmental agencies for the latest air quality information.
-- End Changed Discussion --
&& .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... The aforementioned upper low will continue to circulate to our north through the day tomorrow. Another disturbance rotating through the southern periphery of the circulation will sharpen up and progress through the area tomorrow. This will lead to the development of showers, and potentially even a few thunderstorms across the entire area tomorrow afternoon. Smoke may once again be present across the area, and temperatures will continue to run below normal, with highs in the low to mid 70s for most (60s in the mountains). The upper low that has been situated to our north for several days now will finally start to progress off toward the east on Saturday. This will lead to height rises aloft, and mostly sunny skies. Temperatures will run a bit closer to normal, with highs in the upper 70s and low 80s for most. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... Shortwave ridging will build over the region Sunday ahead of next closed upper low forming over the western Great Lks early next week. Associated to this closed upper low, a low pressure center and associated cold front will bring widespread showers and thunderstorms late Sunday night through Monday night before cdfnt exits the area early Tue. Overall, guidance has trended wetter and more unstable for Monday, but risk for flooding rains and severe wx still remains low. A brief dry window appears likely Tue behind frontal passage, but upper low passing north of the region Tue night will bring renewed chance of showers and thunderstorms Tue afternoon && .AVIATION /14Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
A plume of thicker smoke is descending down in northerly flow early this morning. Visibility went VIFR at BWI earlier this morning but has sense improved to MVFR. Other terminals will continue to linger around 1 to 1 1/2SM through the morning hours. CHO may even reach IFR later this morning, but have kept them MVFR for now. Gradual improvement is expected through the afternoon hours, with most sites returning back to VFR as winds turn northwesterly, and deeper mixing commences once again. Recent model guidance hints that another plume of smoke may descend down into the area tonight. As a result, visibilities in most TAFs have been dropped to MVFR during that time. Smoke may linger through much of Friday as well, albeit likely not as thick as what is currently ongoing. Outside of smoke, the next potential weather impact to the terminals will be showers, and a few thunderstorms Friday afternoon. Winds will be out of the north this morning, and then northwest this afternoon through Saturday. Dry Sunday. Widespread showers and thunderstorms Monday with flight restrictions likely at time.
-- End Changed Discussion --
&& .MARINE... Prevailing sub-SCA level winds are expected over the waters through Saturday. Winds will generally be out of the northwest, but may be out of the south for a short time later this afternoon into this evening for the middle Bay and lower tidal Potomac. Smoke will cause reduced visibility over the waters through at least Friday. A few showers and storms may move over the wider waters of the lower tidal Potomac and middle Bay late this morning into early this afternoon. Special Marine Warnings may be needed for any of the stronger storms. SCA conditions are likely Saturday night into Monday night. T-storms are likely on Monday. && .TIDES/COASTAL FLOODING... Sensitive tide locations will reach Action Stage during the highest diurnal tide over the next couple of days. Tidal anomalies should remain low, and no flooding is currently forecast. However, sensitive locations like Annapolis and DC SW Waterfront will be close. && .LWX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
DC...None. MD...None. VA...None. WV...None. MARINE...None.
-- End Changed Discussion --
&& $$ SYNOPSIS...KJP NEAR TERM...ADS/KJP/ADM SHORT TERM...KJP LONG TERM...LFR AVIATION...LFR/KJP/ADM MARINE...LFR/KJP TIDES/COASTAL FLOODING...KJP

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.