A strong upper-level disturbance and its associated cold front moved into Maryland on the 25th. Hot and humid conditions ahead of the front led to high amounts of instability.
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.
A strong upper-level disturbance and its associated cold front moved into Maryland on the 25th. Hot and humid conditions ahead of the front led to high amounts of instability. Showers and thunderstorms developed along and ahead of the cold front. Due to the high amounts of instability, thunderstorms were able to mix down strong winds from aloft causing significant amounts of damage across portions of 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 Jul 25, 2:04 PM EST, 3 minutes earlier.
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</html>HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 159 PM EDT SUN JUL 25 2010 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 261000- 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-NORTHERN BALTIMORE-HARFORD- SOUTHERN BALTIMORE-PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS- CALVERT-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX- ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA- KING GEORGE- 159 PM EDT SUN JUL 25 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MARYLAND PORTION OF THE CHESAPEAKE BAY...TIDAL POTOMAC RIVER...AND ADJACENT COUNTIES IN CENTRAL MARYLAND AND NORTHERN VIRGINIA AS WELL AS THE DISTRICT OF COLUMBIA. .DAY ONE...THIS AFTERNOON AND TONIGHT A HEAT ADVISORY IS IN EFFECT UNTIL 8 PM. A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 7PM ACROSS METRO BALTIMORE...AND UNTIL 8PM FOR THE REST OF THE AREA. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON ALONG AND AHEAD OF AN APPROACHING FRONTAL BOUNDARY. THUNDERSTORMS WILL HAVE THE POTENTIAL TO BECOME SEVERE...PRODUCING DAMAGING WIND GUSTS. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE TIDAL POTOMAC AND MARYLAND CHESAPEAKE BAY THIS AFTERNOON AND EVENING. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... THE SKYWARN SPOTTER NETWORK HAS BEEN ACTIVATED THIS AFTERNOON. PLEASE FORWARD ANY STORM REPORTS TO THE NATIONAL WEATHER SERVICE. MDZ003>005-009-010-501-502-VAZ021-025>031-036>040-042-050-051-501- 502-WVZ050>055-501>504-261000- WASHINGTON-FREDERICK MD-CARROLL-MONTGOMERY-HOWARD- EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-HIGHLAND- AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE- NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-LOUDOUN-ORANGE- CULPEPER-NORTHERN FAUQUIER-SOUTHERN FAUQUIER-HAMPSHIRE-MORGAN- BERKELEY-JEFFERSON-PENDLETON-HARDY-WESTERN GRANT-EASTERN GRANT- WESTERN MINERAL-EASTERN MINERAL- 159 PM EDT SUN JUL 25 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN WEST VIRGINIA... NORTHERN AND CENTRAL VIRGINIA...AND CENTRAL AND WESTERN MARYLAND WITH THE EXCEPTION OF GARRETT COUNTY. .DAY ONE...THIS AFTERNOON AND TONIGHT A HEAT ADVISORY IS IN EFFECT UNTIL 8 PM FOR AREAS EAST OF THE BLUE RIDGE MOUNTAINS...PORTIONS OF THE EASTERN WEST VIRGINIA PANHANDLE...CENTRAL MARYLAND AND THE NORTHERN SHENANDOAH VALLEY. SEEN WBCNPWLWX FOR FURTHER DETAILS. A SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 7PM ACROSS NORTHERN MARYLAND... THE POTOMAC HIGHLANDS OF WEST VIRGINIA...AND THE NORTHERN SHENANDOAH VALLEY OF VIRGINIA...AND UNTIL 8PM FOR THE REST OF THE AREA. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON ALONG AND AHEAD OF AN APPROACHING FRONTAL BOUNDARY. THUNDERSTORMS WILL HAVE THE POTENTIAL TO BECOME SEVERE...PRODUCING DAMAGING WIND GUSTS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... THE SKYWARN SPOTTER NETWORK HAS BEEN ACTIVATED THIS AFTERNOON. PLEASE FORWARD ANY STORM REPORTS TO THE NATIONAL WEATHER SERVICE. HTS
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</html>The Dover AFB radar (KDOX), 106 km away, was scanning. The volume nearest the first event began at 19:06 UTC.
70 thunderstorm wind, 2 lightning. Local standard time, as filed.
Widespread branches two inches in diameter were down due to thunderstorm winds.
A wind gust of 58 mph was measured near North Potomac.
A trained spotter estimated thunderstorm wind gusts around 60 mph at Poolesville.
A downed Pine Tree was blocking lanes along Quince Orchard Road. Numerous branches were also down across the roadway.
Tree tops and limbs were down along Apricot Road.
Trees were down along Great Seneca highway near Quince Orchard Road.
A survey revealed snapped and uprooted Hardwood and Softwood trees around North Potomac. Large limbs were snapped and there was considerable branch damage.
A wind gust of 58 mph was measured in Laytonsville.
Numerous trees were snapped.
A tree was uprooted on a car near Gaithersburg High School.
A survey revealed snapped pine trees along with snapped hardwood and softwood trees. Some softwood trees were uprooted.
A survey revealed large limbs snapped and an uprooted pine tree along Glen Road between Travilah Road and Piney Meetinghoure Road.
A large pine tree and several large hardwood limbs were snapped off. A tree was also uprooted nearby.
A large crane at the Montgomery County Public Works was toppled.
Gude Drive near MD Route 355 was partially blocked due to several down trees.
Numerous trees and power lines were down on route 28 between downtown Rockville and Interstate 270.
A tree was down across the Metro Red Line tracks.
A wind gust of 64 mph was reported near Laytonsville.
Tree damage was noted and a power pole was leaning as a result of strong wind.
A fatality occurred due to a lightning strike at the Watkins Pond Community Garden in Rockville.
Numerous tree branches 5 to 7 inches in diameter were down along Karen Drive.
A wind gust of 62 mph was reported in Gaithersburg.
Portions of large trees were down near Derwood.
A wind gust of 61 mph was measured at the Gaithersburg High School.
The main stem of a large tree was snapped.
A tree was reported down at Gude Drive and Maryland Route 28.
A tree was down on west Montgomery Avenue.
Large limbs were down in the vicinity of Democracy Boulevard and Seven Locks Road.
The entrance ramp to Interstate 495 from River Road was closed due to a tree blocking the road.
Large tree limbs were down.
Three very large trees were down on Aspen Hill Road.
A large tree was down on a house along Danville Court.
A tree one foot diameter was down at the 6100 Block of Selvan Road in Bethesda.
Trees were down near Aspen Hill.
Trees twelve inches in diameter were down along Connecticut Avenue between Aspen Hill and Viers Mill Road.
Trees were blocking the exit off the Capital Beltway onto Connecticut Avenue.
U.S. 29 was closed at Southwood Avenue due to a downed tree.
A tree six inches in diameter was down across the intersection of Route 193 and 320.
A wind gust of 66 mph was reported near White Oak.
A concrete grounded fence was blown down on Fenton Street between Wayne Avenue and Bonifant Avenue.
A tree was down over the road and several branches were down.
Numerous trees were damaged with some wires down. Wind speeds were estimated around 70 mph.
A tree fell down onto a minivan along Rhode Island Avenue and Odessa Road.
Trees were uprooted in the GreenCastle Lakes subdivision.
Six buildings at an apartment complex received roof damage, including partial and complete removal of roofs.
Two heavy wooden benches were blown into a parking lot.
A tree fell onto a car.
Ten buildings at an apartment complex sustained substantial roof damage.
Large trees were down and a small shed was destroyed. Shingles were also removed from a roof near Greenbelt.
Several trees twelve inches in diameter were down along Mapes Road and Obrien Road.
Several trees of four to five inches in diameter were down along English Avenue and McKay Street.
Several trees six to eight inches in diameter were down along Mapes Road and Cooper Avenue.
Several large trees were down in the vicinity of Stoneybrook Road and Superior Road.
A wind gust of 60 mph was reported near Glenn Dale.
A tree twenty inches in diameter fell along Old Chapel Road and Waldorf Way.
Numerous branches were down near Bowie. A large Gazebo was also blown across a yard.
A tree fell into a house along River Road and Palisades Boulevard.
A tree twelve inches in diameter was down at the intersection of Morning Dove Road and Tern Wing Road.
A branch ten inches in diameter fell onto a house.
A wind gust of 62 mph was recorded at Annapolis.
A fatality occurred due to lightning about a half mile south of the Bay Bridge. A man was struck by lightning while riding on jet skis.
Numerous trees were down near Cape St. Claire.
A wind gust of 60 mph was recorded near Eastport.
A tree was down along the intersection of Old Washington Road and Oak Manor Road.
A tree was down on Bensville Road and another tree was down between Billingsley Road and Robie Manor Drive.
A tree was down on Pomfret Road.
A tree was down near Bumpy Oak Road and Gwynn Road.
Trees and wires were down near Sandy Point Road and Eagle Pond Place.
A tree was down on Fire Tower Road.
A tree was down on Blossom Point Road.
A tree was down on Somerset Street.
A tree was down on Bel Alton Newton Road.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Lightning, Montgomery | 2010-07-25 | 48 | Male | Under Tree | Direct |
| Lightning, Anne Arundel | 2010-07-25 | 65 | Male | In Water | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 2010Every state in 2010This day in weather historyWarnings in Maryland, July 2010
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: 249204, 249205, 250989, 249210, 249206, 249211, 249209, 249212, 249213, 249214, 249215, 249216, 249217, 249221, 249207, 249208, 249219, 249222, 249223, 255285, 249220, 249417, 249418, 249419, 249452, 249453, 249454, 249457, 249455, 249458, 249456, 249420, 249460, 249461, 249474, 249462, 249467, 249468, 249471, 249465, and more.