Isolated severe thunderstorms produced a few instances of wind damage over central and western Maryland.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS LWX wrote it up.
Isolated severe thunderstorms produced a few instances of wind damage over central and western Maryland.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Baltimore/Washington wrote its last area forecast discussion before the first event at Aug 26, 9:18 AM EST, 4 hours 22 minutes earlier.
Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 1018 AM EDT Thu Aug 26 2021 .SYNOPSIS... High pressure will remain situated near our region through the end of the week. A front will drop down into the region from the Great Lakes late Friday into Saturday and stall nearby through early next week. Another front may impact our region midway through next week. && .NEAR TERM /THROUGH TONIGHT/... Previous Discussion.... Upper-level and surface high pressure will remain over the Atlantic through tonight, and a southerly flow around this system will usher in more hot and humid conditions this afternoon, and it will remain warm and humid tonight. There is some weak shortwave energy aloft, which can be seen on the water vapor imagery, and with a light surface flow, there will be terrain circulation along with a surface trough between the Appalachians and the Blue Ridge. Low-level moisture continues to be prevalent with dewpoints well into the 60s and 70s. The increased dewpoints along with weak shortwave energy will cause moderate instability, with 1500-2500 J/KG of MLCAPE most likely. The surface trough and terrain circulation will combine with the increased instability for scattered to numerous showers and thunderstorms this afternoon and evening. Convection is most likely to develop between the Appalachians and Blue Ridge Mountains this afternoon. Convection may propagate east of the Blue Ridge toward the metro areas late this afternoon and evening. Also for the metro areas, an isolated t-storm is also this afternoon ahead of activity approaching from the west due to boundaries associated from the nearby Bay and Potomac River. Shear and mid-level lapse rates will remain weak, but there will be enough instability alone for a few strong to perhaps severe storms (damaging wind gusts being the primary threat). Also, with slow storm motion, a localized flood threat is possible as well, especially near and west of the Blue Ridge where convection will be more widespread, and any storm could remain nearly stationary over the terrain/convective boundaries before a cold pool eventually takes over. Heat indices will most likely top off in the upper 90s to lower 100s (hottest values near and east of Interstate 95). Confidence is too low for any heat headlines at this time. Convection should dissipate overnight with the loss of daytime heating, but it will remain warm and humid. Patchy fog is also expected, and some fog may be locally dense especially in areas that receive rainfall this afternoon and evening. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... Upper-level high pressure will remain nearby for Friday, bringing more hot and humid conditions with max temps into the 90s for many locations and heat indices most likely in the upper 90s to lower 100s (hottest values around and east of Interstate 95). A weak cold front will approach from the north, but it should stay to the north for Friday. However, a pressure trough will be present while more shortwave energy passes nearby to the north. Therefore, more popup showers and thunderstorms are possible. Some may be strong to severe due to moderate instability, despite weak shear and mid-level lapse rates. The best chance for storms appear that it will be near and north of Interstate 66 and US 50, where heights will be a bit lower closer to the shortwave energy. However, with a light flow and terrain circulation, bay and river breezes as well as mountains may trigger a few storms farther south as well. The shortwave will likely pass by to the north Friday night into early Saturday. There is some disagreement among guidance as to how strong this shortwave will be along with its exact track. If it is stronger and farther south, then it may have a reflection down to the low-levels or even surface, which means that low-level forcing may tap into the warm and humid air bringing a better chance for showers and thunderstorms Friday night, despite loss of daytime heating. If this scenario plays out, heavy rain could be an issue. However, if the shortwave is weaker, then precipitation will dissipate overnight with the loss of daytime heating. Current forecast leans a little closer to the second scenario, but this will have to be monitored closely. The shortwave will slowly slide to the east Saturday, but a weak cold front will likely move into the area from the north and east. The boundary will separate marine air from the hot and humid airmass that has been in place. With a wind shift over the area, this will enhance the chances for showers and thunderstorms. Some storms may be strong to perhaps severe, especially along and southwest of the boundary, and some storms may produce heavy rainfall anywhere. Convection should dissipate Saturday night in coverage, but low clouds and areas of fog are possible. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... The upper ridge will begin to break down Sunday into next week, with subtle height falls occurring during this time period. Given the continued head and humidity across the region, thunderstorms will again be possible each afternoon. This will be more of the typical afternoon pop-up activity, primarily focused on the terrain circulations west of the Blue Ridge and the Bay/river breezes to the east. Isolated severe storms and instances of flooding are possible across the region during this time. The forecast for the middle of the week next week is a bit more uncertain at this time. The National Hurricane Center is monitoring a tropical disturbance in the Caribbean right now, which may impact the Gulf Coast this weekend. This system will then come in our general direction by mid-week. So, will have to monitor any tropical development in the coming days and see how guidance trends in regards to any potential impacts for our region. For now though, far too many questions in the forecast to say anything for certain. For now, keeping chance POPs in Tue/Wed. Monitor hurricanes.gov for updates on the tropical weather outlook in the coming days. && .AVIATION /14Z THURSDAY THROUGH MONDAY/... Previous Discussion.... Scattered thunderstorms are expected this afternoon and evening. The best chance for a storm will be across KMRB and KCHO, but storms are possible across the rest of the terminals as well. Gusty winds may accompany any storm. For Friday and Saturday, thunderstorms are possible each day, especially during the afternoon and evening hours (although convection may persist Friday night for some of the terminals). Patchy fog is expected Friday night into Saturday, and low clouds/fog may be more widespread Saturday night. Generally expecting light and variable surface flow Sunday into Monday outside of any thunderstorms. Expecting VFR conditions during this period, again outside of thunderstorms. Could also see early morning fog each morning, which will be most likely in areas that see rain the prior day. && .MARINE... Previous Discussion... High pressure over the Atlantic will cause a light southerly or onshore flow through Friday night. A boundary will move into the area from the north and east Saturday and it will stall out nearby. As of now, it appears that the gradient should be light, keeping winds below SCA levels for most of the time. Showers and thunderstorms are possible each day through Saturday night. The best chance for thunderstorms will be in the afternoon/evening hours each day, and gusty winds may accompany any storm that develops. For Friday night, showers and thunderstorms may hang around into the overnight hours, but confidence is low at this time. Generally light (and variable) flow is expected outside of showers and thunderstorms Sunday into Monday, so no SCAs expected during this period, but could see an SMW or two being necessary for any thunderstorms that may develop over the waters. && .TIDES/COASTAL FLOODING... Tide levels are forecast to remain slightly elevated over the next several days. Although flooding is not explicitly forecast, caution (or near minor) stages are possible at more vulnerable tidal locations such as DC SW Waterfront and Annapolis through the end of the week. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...None. && SYNOPSIS...BJL NEAR TERM...BJL/KLW SHORT TERM...BJL LONG TERM...CJL AVIATION...KLW/CJL MARINE...KLW/CJL TIDES/COASTAL FLOODING...BJL
Hazardous Weather Outlook National Weather Service Baltimore MD/Washington DC 518 AM EDT Thu Aug 26 2021 ANZ530>543-DCZ001-MDZ008-011-013-014-016>018-504-506-508- VAZ052>057-271000- Chesapeake Bay north of Pooles Island MD- Chesapeake Bay from Pooles Island to Sandy Point MD- Chesapeake Bay from Sandy Point to North Beach MD- Chesapeake Bay from North Beach to Drum Point MD- Chesapeake Bay from Drum Point MD to Smith Point VA- Tidal Potomac from Key Bridge to Indian Head MD- Tidal Potomac from Indian Head to Cobb Island MD- Tidal Potomac from Cobb Island MD to Smith Point VA- Patapsco River including Baltimore Harbor- Chester River to Queenstown MD-Eastern Bay- Choptank River to Cambridge MD and the Little Choptank River- Patuxent River to Broomes Island MD- Tangier Sound and the inland waters surrounding Bloodsworth Island-District of Columbia-Cecil-Southern Baltimore- Prince Georges-Anne Arundel-Charles-St. Marys-Calvert- Central and Southeast Montgomery-Central and Southeast Howard- Southeast Harford-Prince William/Manassas/Manassas Park-Fairfax- Arlington/Falls Church/Alexandria-Stafford-Spotsylvania- King George- 518 AM EDT Thu Aug 26 2021 This Hazardous Weather Outlook is for the Maryland portion of the Chesapeake Bay, Tidal Potomac River, and I-95 corridor through central Maryland, northern Virginia, and District of Columbia. .DAY ONE...Today and Tonight A severe thunderstorm capable of producing damaging wind gusts is possible this afternoon and evening. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Isolated severe thunderstorms or instances of flash flooding are possible during the afternoon and evening hours each day. Heat indices up to 105 degrees are possible Thursday afternoon. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed, especially later this week. MDZ003>006-503-505-507-VAZ025>031-036>040-050-051-501-502-505>508- WVZ050>053-055-271000- Washington-Frederick MD-Carroll-Northern Baltimore- Northwest Montgomery-Northwest Howard-Northwest Harford-Augusta- Rockingham-Shenandoah-Frederick VA-Page-Warren-Clarke-Nelson- Albemarle-Greene-Madison-Rappahannock-Orange-Culpeper- Northern Fauquier-Southern Fauquier-Western Loudoun- Eastern Loudoun-Northern Virginia Blue Ridge- Central Virginia Blue Ridge-Hampshire-Morgan-Berkeley-Jefferson- Hardy- 518 AM EDT Thu Aug 26 2021 This Hazardous Weather Outlook is for portions of eastern West Virginia, northern and central Virginia, and central and western Maryland. .DAY ONE...Today and Tonight A few severe storms capable of producing damaging wind gusts are possible this afternoon and evening. Isolated instances of flash flooding are possible as well. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Isolated severe thunderstorms or instances of flash flooding are possible during the afternoon and evening hours each day. Heat indices may approach 100 degrees Thursday afternoon. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed, especially later this week. MDZ001-501-502-VAZ503-504-WVZ501>506-271000- Garrett-Extreme Western Allegany-Central and Eastern Allegany- Western Highland-Eastern Highland-Western Grant-Eastern Grant- Western Mineral-Eastern Mineral-Western Pendleton- Eastern Pendleton- 518 AM EDT Thu Aug 26 2021 This Hazardous Weather Outlook is for the Allegheny Front counties in western Maryland, eastern West Virginia, and Highland County Virginia. .DAY ONE...Today and Tonight A few severe storms capable of producing damaging wind gusts are possible this afternoon and evening. Isolated instances of flash flooding are possible as well. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Isolated severe thunderstorms or instances of flash flooding are possible during the afternoon and evening hours each day. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed, especially later this week.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
141 PM EDT THU AUG 26 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0135 PM MARINE TSTM WIND QUANTICO MARINE CORP 38.51N 77.30W
08/26/2021 E39 MPH PRINCE WILLIAM VA AWOS
&&
EVENT NUMBER LWX2105606
DHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
213 PM EDT THU AUG 26 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0148 PM TSTM WND DMG 3 ENE GARRISONVILLE 38.51N 77.37W
08/26/2021 STAFFORD VA DEPT OF HIGHWAYS
TREE DOWN ON NORTHBOUND US-1 JEFFERSON DAVIS HIGHWAY
NEAR VA-637 TELEGRAPH ROAD.
&&
EVENT NUMBER LWX2105607
DHPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
215 PM EDT THU AUG 26 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0143 PM TSTM WND DMG 1 WSW TRIANGLE 38.54N 77.34W
08/26/2021 PRINCE WILLIAM VA EMERGENCY MNGR
TREE DOWN ON ROUTE 1 NEAR THE INTERSECTION WITH JOPLIN
ROAD
&&
EVENT NUMBER LWX2105608
ADMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
217 PM EDT THU AUG 26 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0150 PM TSTM WND DMG 1 W WIDEWATER 38.46N 77.34W
08/26/2021 STAFFORD VA 911 CALL CENTER
TREE DOWN ON POWER LINES IN THE 100 BLOCK OF VA-635
DECATUR ROAD.
&&
EVENT NUMBER LWX2105609
DHThe Sterling radar (KLWX), 74 km away, was scanning. The volume nearest the first event began at 18:37 UTC.
4 thunderstorm wind. Local standard time, as filed.
A tree was reported down on northbound MD-382 Croom Road at River Airport Road.
A tree was reported down on westbound MacArthur Boulevard near Persimmon Tree Road.
A few branches about two inches in diameter blew down along Blenheim Road North.
Numerous trees blew down in the Flintstone area, including along Murrays Branch Road and Williams Road at Stickley Road. Wires blew down near the intersection of Georges Creek Road and Welsh Hill Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 2021Every state in 2021This day in weather historyWarnings in Maryland, August 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 969454, 969455, 969456, 969457.