A subtropical ridge was over the Mid Atlantic with northwesterly flow leading to hot and humid conditions. This led to a unstable atmosphere and thunderstorms formed.
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 subtropical ridge was over the Mid Atlantic with northwesterly flow leading to hot and humid conditions. This led to a unstable atmosphere and thunderstorms formed.
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 Jun 25, 1:28 PM EST, 6 hours 49 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 228 PM EDT TUE JUN 25 2013 .SYNOPSIS... BERMUDA HIGH PRESSURE WILL PERSIST THROUGH THE MIDDLE OF THIS WEEK. A COLD FRONT WILL APPROACH THE REGION THURSDAY BEFORE STALLING OVER THE AREA FRIDAY. A TROUGH OF LOW PRESSURE WILL IMPACT THE AREA DURING THE WEEKEND AND EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... THE SUBTROPICAL RIDGE REMAINS OVER THE SOUTHERN CONUS WHILE SURFACE HIGH PRESSURE EXTENDS FROM THE SOUTHEASTERN CONUS OUT INTO THE ATLANTIC. A ZONAL FLOW AROUND THE SUBTROPICAL RIDGE WILL CONTINUE OVER OUR AREA THROUGH TONIGHT. A WEST-SOUTHWEST FLOW AROUND THE SURFACE HIGH HAS CAUSED HOT AND HUMID CONDITIONS THIS AFTERNOON. MAX TEMPS WILL RANGE FROM NEAR 80 IN THE MOUNTAINS TO THE LOWER AND MIDDLE 90S ACROSS MOST OTHER LOCATIONS. HEAT INDICES WILL TOP OFF AROUND 100 DEGREES IN THE URBAN CORRIDORS AROUND WASHINGTON DC AND BALTIMORE. THE HEAT AND HUMIDITY HAS LED TO AN UNSTABLE ATMOSPHERE. LATEST MESOANALYSIS SHOWS AROUND 1500 J/KG. HOWEVER...THE CAPPING INVERSION HAS HELD IN PLACE ACROSS MOST AREAS...MOST LIKELY DUE TO A DOWNSLOPING COMPONENT TO THE LOW LEVEL FLOW AND MID-LEVEL SUBSIDENCE BEHIND A DEPARTING VORT MAX. CURRENT THINKING IS THAT SURFACE HEATING ALONG WITH FORCING FROM A SURFACE TROUGH SHOULD BE ENOUGH TO OVERCOME THE CAPPING INVERSION FOR ISOLATED/SCATTERED THUNDERSTORMS THIS AFTERNOON. SOME THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY DAMAGING WIND GUSTS AND LARGE HAIL. TONIGHT...MCS ACTIVITY CONTINUES TO MOVE OVER THE GREAT LAKES AND THE OUTFLOW BOUNDARY FROM THIS ACTIVITY HAS MOVED INTO THE OHIO VALLEY. CONVECTION HAS INITIATED AHEAD THIS BOUNDARY OVER THE OHIO VALLEY. THE CONVECTION IS LIKELY TO BECOME MORE ORGANIZED AS IT PROPAGATES EAST TOWARD OUR WESTERN CWA THIS EVENING. THERE IS LITTLE CERTAINTY AS TO WHETHER OR NOT IT WILL SURVIVE EAST OF THE MOUNTAINS...BUT WITH A WESTERLY FLOW ALOFT AND MODERATE INSTABILITY THERE IS A CHANCE FOR SHOWERS AND THUNDERSTORMS TO IMPACT OUR AREA TONIGHT. SHOULD THE CONVECTION HOLD TOGETHER OR DEVELOP INTO AN MCS...THEN SEVERE THUNDERSTORMS ARE POSSIBLE. THE BEST CHANCE FOR THE STRONGER STORMS WILL BE ACROSS THE NORTHERN PORTION OF THE CWA WHERE THE MID AND UPPER-LEVEL FLOW IS STRONGER. MIN TEMPS WILL RANGE FROM THE UPR 60S W OF THE BLUE RIDGE TO THE LOW 70S EAST OF THE BLUE RIDGE...WITH MID 70S IN URBAN/NEAR SHORE LOCALES. PATCHY FOG IS EXPECTED OVERNIGHT...ESPECIALLY IN THE SHELTERED VALLEYS AND RURAL AREAS. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC OCEAN WEDNESDAY AND A WEST-SOUTHWEST FLOW AROUND THIS SYSTEM WILL CONTINUE TO USHER IN HOT AND HUMID CONDITIONS. HEAT INDICES AROUND 100 DEGREES ARE EXPECTED FOR LOCATIONS EAST OF THE BLUE RIDGE MOUNTAINS. THE HEAT AND HUMIDITY WILL LEAD TO MODERATE AMOUNTS OF INSTABILITY. SHORTWAVE ENERGY IN A WESTERLY FLOW ALOFT ALONG WITH A SURFACE TROUGH WILL ACT AS LIFTING MECHANISMS FOR MORE CONVECTION WEDNESDAY. SOME THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY DAMAGING WIND GUSTS AND LARGE HAIL. LOW PRESSURE AND ITS ASSOCIATED COLD FRONT WILL APPROACH THE AREA WEDNESDAY NIGHT BEFORE MOVING INTO THE REGION THURSDAY. MORE SHOWERS AND THUNDERSTORMS ARE LIKELY LATE WEDNESDAY NIGHT AND THURSDAY. THERE IS AN INCREASED CHANCE FOR SEVERE THUNDERSTORMS DURING THIS TIME DUE TO MODERATE INSTABILITY AND INCREASED SHEAR PROFILES. A FEW SHOWERS AND T-STORMS MAY HANG AROUND OVERNIGHT THURSDAY AS THE FRONT REMAINS NEAR OUR AREA. && .LONG TERM /FRIDAY THROUGH TUESDAY/... THE COLD FRONT WILL DISSIPATE OVERHEAD FRIDAY AND A LONGWAVE UPPER-LEVEL TROUGH IS EXPECTED TO BUILD OVER THE MIDWEST DURING THE WEEKEND THROUGH EARLY NEXT WEEK. SURFACE HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC OCEAN DURING THIS TIME AND A SOUTHERLY FLOW WILL CONTINUE TO USHER IN WARM AND HUMID CONDITIONS. THE WARM AND HUMID AIRMASS WILL COMBINE WITH FORCING FROM THE UPPER-LEVEL TROUGH TO BRING UNSETTLED CONDITIONS DURING THIS TIME. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EVENING. SOME THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE GUSTY WINDS AND HAIL. PATCHY FOG/BR ARE EXPECTED LATE TONIGHT AND EARLY WEDNESDAY MORNING. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THE END OF THE WEEK WITH THE BEST CHANCE IN THE AFTERNOON AND EVENING. MVFR/IFR CONDITIONS ARE POSSIBLE DURING THE EARLY MORNING HOURS EACH DAY. && .MARINE... SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND POSSIBLY TONIGHT. THUNDERSTORMS WILL HAVE THE POTENTIAL TO PRODUCE GUSTY WINDS AND HAIL. SOUTHWEST WINDS ARE EXPECTED THROUGH TONIGHT WITH GUSTS AROUND 15 KNOTS. SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH THE END OF THE WEEK WITH THE BEST CHANCE IN THE AFTERNOON AND EARLY EVENING. HOT AND HUMID CONDITIONS AND A SOUTHERLY FLOW WILL CONTINUE DURING THIS TIME. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && SYNOPSIS...BAJ/HAS NEAR TERM...BJL SHORT TERM...BJL LONG TERM...HAS AVIATION...BJL/HAS MARINE...BJL/HAS
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 905 PM EDT TUE JUN 25 2013 ANZ530>543-DCZ001-MDZ006-007-011-013-014-016>018-VAZ052>057- 261215- 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- 905 PM EDT TUE JUN 25 2013 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...TONIGHT SEVERE THUNDERSTORM WATCH 367 IS IN EFFECT FOR MUCH OF THE INTERSTATE 95 CORRIDOR OF EASTERN MARYLAND AND NORTHERN VIRGINIA...INCLUDING MUCH OF THE MARYLAND CHESAPEAKE BAY AND TIDAL POTOMAC RIVER...THROUGH 2 AM. DAMAGING WIND GUSTS FROM AN APPROACHING LINE OF SEVERE THUNDERSTORM WILL BE THE MAIN THREAT. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY AN ISOLATED SEVERE THUNDERSTORM THREAT IS EXPECTED AGAIN FOR WEDNESDAY AFTERNOON INTO THE EVENING. HEAT INDICES AROUND 100 DEGREES ARE EXPECTED WEDNESDAY AFTERNOON AND EARLY EVENING...ESPECIALLY IN THE URBAN CENTERS OF BALTIMORE AND WASHINGTON DC. AN INCREASED SEVERE THUNDERSTORM THREAT IS EXPECTED IN ASSOCIATION WITH A COLD FRONT THURSDAY AND POSSIBLY FRIDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THURSDAY AND FRIDAY FOR PORTIONS OF THE WATERS. .SPOTTER INFORMATION STATEMENT... SKYWARN HAS BEEN ACTIVATED. PLEASE RELAY REPORTS OF SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE. MDZ003>005-009-010-501-502-VAZ025>031-036>040-042-050-051-501>504- WVZ050>053-055-501>506-261215- WASHINGTON-FREDERICK MD-CARROLL-MONTGOMERY-HOWARD- EXTREME WESTERN ALLEGANY-CENTRAL AND EASTERN ALLEGANY-AUGUSTA- ROCKINGHAM-SHENANDOAH-FREDERICK VA-PAGE-WARREN-CLARKE-NELSON- ALBEMARLE-GREENE-MADISON-RAPPAHANNOCK-LOUDOUN-ORANGE-CULPEPER- NORTHERN FAUQUIER-SOUTHERN FAUQUIER-WESTERN HIGHLAND- EASTERN HIGHLAND-HAMPSHIRE-MORGAN-BERKELEY-JEFFERSON-HARDY- WESTERN GRANT-EASTERN GRANT-WESTERN MINERAL-EASTERN MINERAL- WESTERN PENDLETON-EASTERN PENDLETON- 905 PM EDT TUE JUN 25 2013 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...TONIGHT SEVERE THUNDERSTORM WATCH 365 IS IN EFFECT FOR MUCH OF THE POTOMAC HIGHLANDS AND PORTIONS OF THE NORTHERN SHENANDOAH VALLEY... INCLUDING PORTIONS OF NORTH CENTRAL MARYLAND AND EXTREME NORTHERN VIRGINIA...THROUGH 2 AM. SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS THESES AREAS LATE TONIGHT...WITH DAMAGING WIND GUSTS THE MAIN THREAT. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY AN ISOLATED SEVERE THUNDERSTORM THREAT IS EXPECTED AGAIN FOR WEDNESDAY AFTERNOON INTO THE EVENING. HEAT INDICES WILL APPROACH 100 DEGREES WEDNESDAY AFTERNOON AND EARLY EVENING FOR LOCATIONS EAST OF THE BLUE RIDGE MOUNTAINS. AN INCREASED SEVERE THUNDERSTORM THREAT IS EXPECTED IN ASSOCIATION WITH A COLD FRONT THURSDAY AND POSSIBLY FRIDAY. .SPOTTER INFORMATION STATEMENT... SKYWARN HAS BEEN ACTIVATED. PLEASE RELAY REPORTS OF SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE.
PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
840 PM EDT TUE JUN 25 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0332 PM TSTM WND DMG 2 WNW LEESBURG 39.11N 77.60W
06/24/2013 LOUDOUN VA NWS EMPLOYEE
10-15 LARGE TREES 18-24 INCH DIA UPROOTED LARGE LIMBS
DOWN AND BLOCKING W AND OD TRAIL AT MILE MARKER 37.
&&
CORRECTED LOCATION
EVENT NUMBER LWX1300505
LEEThe Sterling radar (KLWX), 76 km away, was scanning. The volume nearest the first event began at 01:17 UTC.
12 thunderstorm wind. Local standard time, as filed.
There was one tree down in the city and multiple wires down.
There was a tree into a house on Brandenburg Hallow Road.
There were two large trees down blocking Jefferson Pike north of Burkittsville Road.
There were a couple trees knocked onto Sullivan Road. There was damage to Sullivan Road community pool.
There was one large pine tree snapped and several other large limbs downed from other trees. One limb was on a vehicle. The damage was isolated to three homes in the community.
There was a tree down on Grand Valley Road.
There were a few trees down. A wooden swing set toppled over and shudders were off of a house and missing. There was fencing down and a shed moved off its foundation. A vehicle slid onto a curb.
There were several trees snapped and one was on a home.
There was a large tree down blocking northbound lanes of MD 152 at Rochelle Road.
There were a couple of five inch diameter tree limbs broken.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Maryland in 2013Every state in 2013This day in weather historyWarnings in Maryland, June 2013
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: 462595, 462596, 462599, 462604, 462610, 462621, 462606, 462608, 462613, 462614, 462616, 462617.