A hot and humid air mass developed over the Mid Atlantic ahead of a strong cold front on August 25th. Temperatures climbed into the mid 90s by noon.
Every event with a place to put it; 7 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 hot and humid air mass developed over the Mid Atlantic ahead of a strong cold front on August 25th. Temperatures climbed into the mid 90s by noon. These temperatures combined with high humidity created heat index values around 105. Showers and thunderstorms developed during the late afternoon as the cold front approached the region. Some of these storms became severe, producing large hail and damaging winds that downed trees and power lines.
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 25, 10:18 AM EST, 42 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1118 AM EDT SAT AUG 25 2007
.SYNOPSIS...
HIGH PRESSURE OVER THE CAROLINAS AND A COLD FRONT OVER THE ST.
LAWRENCE RIVER DRIFTING SE. HOT AND HUMID CONDITIONS SATURDAY
ACROSS THE MID ATLANTIC STATES. THUNDERSTORMS EXPECTED DURING THE
AFTERNOON AND EVENING TODAY AND SUNDAY. THE COLD FRONT WILL MOVE
THROUGH THE REGION SUNDAY AND STALL OVER SOUTHERN VIRGINIA. HIGH
PRESSURE WILL BUILD IN BY MID NEXT. ANOTHER COLD FRONT IS LIKELY
BY WEEKS END.
&&
.NEAR TERM /UNTIL 10 PM THIS EVENING/...
THE MID ATLANTIC IS SHAPING UP FOR ONE OF THE HOTTEST DAYS OF THE
YEAR...ESPECIALLY FACTORING IN THE HIGH HUMIDITY WITH CURRENT
DEWPOINTS IN THE L70S WITH A FEW MID 70S. THIS TREND EXPECTED TO
LINGER THRU THE AFTN WITH TEMPS ALREADY IN THE MID TO U80S ACROSS
THE I-95 CORRIDOR AND THE SHENANDOAH VALLEY BEFORE 11AM. LIGHT
SOUTHERLY WINDS FOR MUCH OF THE AFTN CONTRIBUTING TO THE MOISTURE
POOLING AND WIDESPREAD HAZINESS.
HIGH AMOUNTS OF AVAILABLE CONVECTIVE ENERGY ON THE 12Z IAD
SOUNDING...NEARLY 4000 J/KG. SLIGHTLY MORE STEERING FLOW WITH THE
APPROACHING SHORTWAVE...CURRENTLY DRAPED ACROSS THE SOUTHERN GREAT
LAKES. FAVORABLE LAPSE RATES AND LOW CONV INHIBITION WILL MAKE FOR
SOME ISOLATED STRONG AND POSSIBLY SEVERE STORMS. LL INVERSION STRONG
ENOUGH TO HOLD OFF CONVECTION FOR EARLY AFTN...A FEW ISOLATED IN THE
MTNS WITH TERRAIN EFFECTS AIDING IN INITIATION. STORMS THAT DEVELOP
THIS AFTN WILL CREATE BETTER ENVIRONMENTAL FORCING FOR CONVECTION
THAT DOESN/T BREAK THE CAP UNTIL MAX HEATING THIS AFTN. CLEARING
SKIES ACROSS THE REGION WILL BE FAVORABLE FOR MAX HEATING.
&&
.SHORT TERM /10 PM THIS EVENING THROUGH SUNDAY NIGHT/...
CD FNT ACROSS NRN VA/MD ARND 06Z. OBVIOUSLY W/ ATMOSPHERE AS JUICED
AS THIS ONE WL BE THIS COMBO WL LKLY LEAD TO CNVCTN THIS EVE.
ARW/WRF DVLPS STORMS ON THE MTNS LATE THIS AFTN WHICH WL SPREAD E
DURG EVE HRS. XTRM NWRN PART OF THE CWA IS OUTLOOKED SVR. WOULDNT
BE SURPRISED TO SEE THIS MOVED FURTHER SE LATER TDA.
WOODY
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
A COLD FRONT WILL APPROACH THE AREA ON SUN AND PUSH SOUTH OF THE
AREA BY MON. A WEAK WAVE FORMING ALG THE FRONT WILL ENHANCE THE
THREAT FOR SHRAS. HIGH PRES WILL BUILD FOR THE MIDDLE OF NEXT WEEK.
ANOTHER FRONTAL BDRY WILL APPROACH THE AREA LATE THU AND STALL OFF
THE ATLC COAST.
ROSA
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
ISOLATED AFTN TSTRMS ACROSS THE MTNS...BECOMING MORE WIDESPREAD
QUICKLY THROUGHOUT THE AFTN...SPREADING TO LOCATIONS OUTSIDE THE
FOOTHILLS AND PIEDMONT. CU FIELD SHOULD BECOME WIDESPREAD BEFORE MAX
HEATING...THEN VCTS FOR DC METRO TAF SITES LATER IN THE AFTN WITH
BETTER EASTWARD MOVEMENT OF CONVECTION LATER TODAY.
NMRS RW AND TRW PSBL SUN. HIGH PRES RETURNS MON NGT-WED.
&&
.MARINE...
WINDS AGAIN ACROSS THE BAY STAYING JUST BELOW SCA CRITERIA TODAY AND
TONIGHT. WEAK FRONTAL PASSAGE OVERNIGHT TONIGHT AND EARLY SUNDAY
WITH CHANNELING EFFECTS OF SOUTHERLY WINDS UP THE CHESAPEAKE
STRONGEST BEFORE FROPA...THEN A NW/ERLY SHIFT ON SUNDAY MORNING.
MORE TSTRMS EXPECTED SUNDAY AFTN/EVENING.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR DCZ001.
MD...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR MDZ003>007-
009>011-013-014-016>018.
VA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR VAZ025>031-
036>042-050>057.
WV...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR WVZ051>053.
MARINE...NONE.
&&
SYNOPSIS...GMS
NEAR TERM...GMS
AVIATION...GMS
MARINE...GMSHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1121 AM EDT SAT AUG 25 2007 ANZ530>537-DCZ001-MDZ003>007-009>011-013-014-016>018-501-502- VAZ021-025>031-036>042-050>057-WVZ050>055-501>504-261000- 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- DISTRICT OF COLUMBIA-WASHINGTON-FREDERICK MD-CARROLL- NORTHERN BALTIMORE-HARFORD-MONTGOMERY-HOWARD-SOUTHERN BALTIMORE- PRINCE GEORGES-ANNE ARUNDEL-CHARLES-ST. MARYS-CALVERT- EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-HIGHLAND- AUGUSTA-ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE- NELSON-ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-FAUQUIER-LOUDOUN- ORANGE-CULPEPER-PRINCE WILLIAM/MANASSAS/MANASSAS PARK-FAIRFAX- ARLINGTON/FALLS CHURCH/ALEXANDRIA-STAFFORD-SPOTSYLVANIA- KING GEORGE-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-PENDLETON-HARDY- WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL- 1121 AM EDT SAT AUG 25 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR MARYLAND WEST OF THE EASTERN SHORE INCLUDING THE CHESAPEAKE BAY AND EAST OF GARRETT COUNTY...EASTERN WEST VIRGINIA...NORTHERN AND CENTRAL VIRGINIA... WASHINGTON DC AND THE TIDAL POTOMAC RIVER. .DAY ONE...THIS AFTERNOON AND TONIGHT A HEAT ADVISORY IS IN EFFECT MAINLY ALONG AND EAST OF THE INTERSTATE 81 CORRIDOR. HEAT INDEX VALUES WILL BE AROUND 105 DEGREES THIS AFTERNOON. SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE LATER THIS AFTERNOON AND EVENING. THUNDERSTORMS WILL HAVE THE POTENTIAL TO BECOME SEVERE...CAPABLE OF PRODUCING DAMAGING WIND GUSTS AND LARGE HAIL. HEAVY RAINFALL WILL ALSO BE POSSIBLE. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ONCE AGAIN ON SUNDAY AS A COLD FRONT DROPS SOUTH OVER THE MID ATLANTIC REGION. A FEW OF THE THUNDERSTORMS MAY BECOME SEVERE...PRODUCING LARGE HAIL AND DAMAGING WIND GUSTS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NECESSARY BOTH TODAY AND SUNDAY.
The Sterling radar (KLWX), 161 km away, was scanning. The volume nearest the first event began at 18:42 UTC.
16 thunderstorm wind, 9 heat, 4 hail. Local standard time, as filed.
Automated Surface Observations reported high temperatures and relative humidities that produced heat index values of 105 and above.
Automated Surface Observations reported high temperatures and relative humidities that produced heat index values of 105 and above.
Automated Surface Observations reported high temperatures and relative humidities that produced heat index values of 105 and above.
Automated Surface Observations reported high temperatures and relative humidities that produced heat index values of 105 and above.
Automated Surface Observations reported high temperatures and relative humidities that produced heat index values of 105 and above.
Automated Surface Observations reported high temperatures and relative humidities that produced heat index values of 105 and above.
Automated Surface Observations reported high temperatures and relative humidities that produced heat index values of 105 and above.
Automated Surface Observations reported high temperatures and relative humidities that produced heat index values of 105 and above.
Automated Surface Observations reported high temperatures and relative humidities that produced heat index values of 105 and above.
Shenandoah County Emergency Management reported trees down in Strasburg, VA.
A Cooperative Observer reported golf ball size hail in Dale Enterprise, VA.
The Fire and Rescue Department reported trees down on power lines along Millwood Avenue in the City of Winchester.
A Trained Spotter measured winds at 60 mph. The Frederick Emergency Operations Center reported trees down in Stephens City.
A Trained Spotter reported penny size hail in Stephens City, VA. Frederick County Emergency Management also reported hail in the same area.
Page County Emergency Management reported numerous trees down at the intersection of Old Stanley Road and Forest Drive and Old Stanley Road as well as Pond Avenue. Ten homes were damaged by trees and one storage facility was destroyed. A trailer camper was blown over. Power lines were also downed.
Clarke County Emergency Management reported trees down in Boyce, VA.
Madison County Emergency Management reported trees down in Rochelle, VA.
Fauquier County Emergency Management reported trees down in the central and western parts of the county.
A Trained Spotter measured wind gusts of 59 and 66 mph in Lovettsville, VA.
Rappahannock County Emergency Management reported trees down in Castleton, VA.
Fauquier County Emergency Management reported trees down in Markham, VA.
Culpeper County Emergency Management reported trees down in Griffinsburg, VA.
A Trained Spotter reported trees and power lines down in the City of Staunton.
Prince William County Emergency Management reported trees down in Dumfries, VA.
A Trained Spotter reported penny size hail northeast of Charlottesville, VA.
A Trained Spotter reported penny size hail in Haywood, VA.
Broadcast media contact reported trees down north of Ruckersville, VA. Route 29 was closed north of Route 33 due to downed trees on the road.
A Trained Spotter reported a tree down on a house near the intersection of Burke Road and Burke Lake Road.
Fairfax County Emergency Management reported a tree down on a house on Hamlet Street in Springfield, VA.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Virginia in 2007Every state in 2007This day in weather historyWarnings in Virginia, August 2007
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: 51939, 51940, 51941, 51942, 51943, 51944, 51945, 51946, 51947, 51959, 51960, 51961, 52065, 52083, 52066, 52067, 52068, 52069, 52070, 52071, 52072, 52073, 52074, 52075, 52076, 52077, 52078, 52079, 52081.