A slow moving cold front helped trigger a few severe thunderstorms across southeastern Pennsylvania on the evening of the 23rd.
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 PHI wrote it up.
A slow moving cold front helped trigger a few severe thunderstorms across southeastern Pennsylvania on the evening of the 23rd.
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 Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Jun 23, 9:16 PM EST, 49 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1016 PM EDT MON JUN 23 2008 .SYNOPSIS... A COLD FRONT WILL MOVE ACROSS EASTERN PENNSYLVANIA, NORTHEASTERN MARYLAND, DELAWARE AND NEW JERSEY TONIGHT. A SECONDARY TROUGH WILL CROSS THE AREA TUESDAY. HIGH PRESSURE IS FORECAST TO BUILD IN FOR TUESDAY NIGHT AND WEDNESDAY. A WARM FRONT IS EXPECTED TO LIFT SLOWLY THROUGH OUR REGION WEDNESDAY NIGHT AND THURSDAY. ANOTHER COLD FRONT IS SLATED TO ARRIVE SATURDAY NIGHT. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... THE SURFACE BOUNDARY WAS ENTERING OUR NORTHWESTERN LOCALES LATE THIS MONDAY EVENING WHILE THE TRAILING MID LEVEL TROF WAS JUST ENTERING WESTERN PA. THERE WAS AN ASSOCIATED UPPER LEVEL JET. CAPES WERE DROPPING SLOWLY AND THE LOWER LEVEL WIND FIELD WASNT VERY IMPRESSIVE, BUT THE UPPER LEVEL SUPPORT, THE LOWER LEVEL FORCING /LOWER LEVEL FRONTOGENESIS WAS WEAK BUT DID EXIST/ AND THE INSTABILITY WERE ENOUGH TO KEEP ACTIVITY FIRING. AS THE NIGHT PROGRESSES, THE INSTABILITY WILL WEAKEN MORE BUT THE MID AND UPPER LEVEL DYNAMICS WILL PERSIST. THAT SHOULD RESULT IN WEAKENING STORMS BUT LIKELY WILL NOT ALLOW ACTIVITY TO DISSAPEAR COMPLETELY. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... THE UPPER LEVEL TROUGH THAT EXTENDED FROM THE EASTERN GREAT LAKES REGION TO THE TENNESSEE RIVER VALLEY THIS AFTERNOON SHOULD CONTINUE TO DRIFT TO THE EAST. THE AXIS OF THE TROUGH IS EXPECTED TO PASS OVERHEAD AROUND MIDDAY ON TUESDAY. WITH THE UPPER LEVEL FEATURE AND WITH SOME MARGINAL INSTABILITY LINGERING OVER OUR AREA, WE HAVE CONTINUED TO MENTION THE CHANCE FOR SHOWERS AND THUNDERSTORMS FOR TUESDAY. DRIER AIR WILL BUILD IN FROM THE WEST FOR TUESDAY NIGHT AND WEDNESDAY, RESULTING IN A MOSTLY CLEAR SKY. THE CENTER OF HIGH PRESSURE IS EXPECTED TO PASS OFF THE COAST ON WEDNESDAY. A RETURN FLOW OF MORE HUMID AIR WILL BECOME ESTABLISHED OVER OUR REGION BEGINNING ON WEDNESDAY NIGHT. WITH THE INCREASING HUMIDITY AND INSTABILITY ON THURSDAY, WE HAVE MAINTAINED THE MENTION OF A CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... THE UPPER PATTERN IS FORECAST TO FLATTEN A BIT BY THE END OF THE WEEK. ANOTHER TROUGH IS ANTICIPATED TO DIG OVER THE NORTH CENTRAL STATES AND THE GREAT LAKES REGION OVER THE WEEKEND. THE TROUGH IS EXPECTED TO SET UP OVER THE EASTERN STATES FOR THE EARLY PART OF NEXT WEEK, KEEPING TEMPERATURES FROM GETTING EXCESSIVELY HOT. A WARM FRONT THAT IS EXPECTED TO LIFT THROUGH OUR REGION ON WEDNESDAY NIGHT AND THURSDAY MAY STALL JUST TO OUR NORTH FOR THURSDAY NIGHT INTO FRIDAY. AS A RESULT, WE WILL KEEP CHANCE POPS IN THE FORECAST. ANOTHER COLD FRONT FROM THE NORTHWEST IS SLATED TO ARRIVE ON SATURDAY NIGHT. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... EXCEPT FOR SCATTERED SHOWERS AND THUNDERSTORMS THAT MOVE THROUGH THE AREA THROUGH MIDNIGHT, VFR CONDITIONS SHOULD PREVAIL THROUGH TUESDAY. THE SCATTERED SHOWERS AND THUNDERSTORMS WILL BE MOVING OUT OF MARYLAND AND CENTRAL PENNSYLVANIA AND HEAD RAPIDLY EAST. HOWEVER, SINCE IT IS NOW PAST SUNSET, WE HAVE LOST THE DAYTIME HEATING AND THE STORMS SHOULD WEAKEN AS THEY HEAD EAST. I HAVE INCLUDED A PERIOD OF CB CLOUDS THIS EVENING WITH THE ANTICIPATED TIMING OF POTENTIAL TSTMS, BUT I DONT THINK MOST AREAS WILL SEE ANY. WITH THE RETURN OF DAYTIME HEATING ON TUESDAY, DRY AIR WILL BE IN PLACE, BUT THE MIXING INDUCED BY THE DAYTIME HEATING WILL RESULT IN GUSTY WINDS DUE TO SOME OF THE WINDS FROM ALOFT BEING MIXED DOWNWARD TO THE GROUND. LOOKING BEYOND 00Z WEDNESDAY...THE NEXT THREAT OF TSTMS WOULD BE ON THURSDAY AND FRIDAY. && .MARINE... CONDITIONS ARE FORECAST TO REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA THROUGH THE FORECAST PERIOD. THE LOOSE GRADIENT AHEAD OF THE APPROACHING WEAK COLD FRONT FOR TONIGHT IS NOT FORECAST TO GENERATE 25 KNOTS OR 5 FOOT SEAS, AT LEAST OUTSIDE OF CONVECTION, AND WAVEWATCH HANDLES THIS NICELY WITH 3 FOOT SEAS FORECAST FOR BUOY 44009. A LIGHT WEST TO WEST-NORTHWEST FLOW TUESDAY SHOULD RETURN TO SOUTHWEST OR SOUTH AS THE WEEK WEARS ON, BUT AGAIN, SPEEDS SHOULD REMAIN BELOW CRITERIA AS WEAK HIGH PRESSURE PREVAILS. A WARM FRONT APPROACHING LATER THIS WEEK MAY IMPACT MARINE CONDITIONS, AND MODEL GUIDANCE WILL BE MONITORED FOR ANY CHANGES IF THE FLOW BECOMES MORE SOUTHEAST AND INCREASES. WAVEWATCH HAS BEEN HABITUALLY RAMPING SEAS UP TO 5 FEET TOWARD THE END OF ITS FORECAST CYCLE FOR THE PAST SEVERAL DAYS, AND DOES SO AGAIN FOR SATURDAY NIGHT AND SUNDAY. FOR NOW, SEAS WILL BE KEPT UNDER 5 FEET THROUGHOUT. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && SYNOPSIS...DELISI NEAR TERM...DELISI SHORT TERM...IOVINO LONG TERM...IOVINO AVIATION...STAUBER
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 430 PM EDT MON JUN 23 2008 DEZ001>004-MDZ008-012-015-019-020-NJZ001-007>010-012>027-PAZ054-055- 060>062-067>071-241000- NEW CASTLE-KENT DE-INLAND SUSSEX-DELAWARE BEACHES-CECIL-KENT MD- QUEEN ANNES-TALBOT-CAROLINE-SUSSEX-WARREN-MORRIS-HUNTERDON-SOMERSET- MIDDLESEX-WESTERN MONMOUTH-EASTERN MONMOUTH-MERCER-SALEM-GLOUCESTER- CAMDEN-NORTHWESTERN BURLINGTON-OCEAN-CUMBERLAND-ATLANTIC-CAPE MAY- ATLANTIC COASTAL CAPE MAY-COASTAL ATLANTIC-COASTAL OCEAN- SOUTHEASTERN BURLINGTON-CARBON-MONROE-BERKS-LEHIGH-NORTHAMPTON- CHESTER-MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA- 430 PM EDT MON JUN 23 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PARTS OF EASTERN PENNSYLVANIA AND NEW JERSEY, DELAWARE AND NORTHEASTERN MARYLAND. .DAY ONE...THIS EVENING AND TONIGHT SCATTERED THUNDERSTORMS ARE EXPECTED INTO TONIGHT. SOME OF THE THUNDERSTORMS THIS EVENING MAY BE ACCOMPANIED BY STRONG WIND GUSTS AND HAIL, ALONG WITH HEAVY RAIN AND FREQUENT LIGHTNING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED. ANZ430-431-450>455-241000- DELAWARE BAY WATERS NORTH OF EAST POINT NJ TO SLAUGHTER BEACH DE- DELAWARE BAY WATERS SOUTH OF EAST POINT NJ TO SLAUGHTER BEACH DE- COASTAL WATERS FROM SANDY HOOK TO MANASQUAN INLET NJ OUT 20 NM- COASTAL WATERS FROM MANASQUAN INLET TO LITTLE EGG INLET NJ OUT 20 NM- COASTAL WATERS FROM LITTLE EGG INLET TO GREAT EGG INLET NJ OUT 20 NM- COASTAL WATERS FROM GREAT EGG INLET TO CAPE MAY NJ OUT 20 NM- COASTAL WATERS FROM CAPE MAY NJ TO CAPE HENLOPEN DE OUT 20 NM- COASTAL WATERS FROM CAPE HENLOPEN TO FENWICK ISLAND DE OUT 20 NM- 430 PM EDT MON JUN 23 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE COASTAL WATERS OF NEW JERSEY AND DELAWARE AND FOR DELAWARE BAY. .DAY ONE...THIS EVENING AND TONIGHT SCATTERED THUNDERSTORMS ARE EXPECTED INTO TONIGHT. SOME OF THE THUNDERSTORMS THIS EVENING MAY BE ACCOMPANIED BY STRONG WIND GUSTS AND HAIL, ALONG WITH HEAVY RAIN AND FREQUENT LIGHTNING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 712 PM EDT MON JUN 23 2008 MDZ012-015-240015- KENT-QUEEN ANNES- 712 PM EDT MON JUN 23 2008 ...A STRONG THUNDERSTORM WILL AFFECT KENT AND QUEEN ANNES COUNTIES... AT 711 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM NEAR CAPE ST. CLAIR...MOVING EAST AT 25 MPH. THE THUNDERSTORM WILL BE NEAR OVERTON...CENTREVILLE AROUND 730 PM...CARVILLE...HOPE AROUND 745 PM...SUDLERSVILLE AND GALENA AROUND 800 PM. VERY HEAVY RAIN WILL FALL FROM THIS STORM...AND WILL CAUSE WATER TO POND ON ROADS AND QUICKLY FILL ROADSIDE DITCHES AND SMALL STREAMS. WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM. EXPECT INTENSE LIGHTNING FROM THIS STORM. DO NOT SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM APPROACHES. NIERENBERG
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 909 PM EDT MON JUN 23 2008 NJZ016>018-021-022-240215- ATLANTIC-CAMDEN-CUMBERLAND-GLOUCESTER-SALEM- 909 PM EDT MON JUN 23 2008 ...A STRONG THUNDERSTORM WILL AFFECT ATLANTIC...CAMDEN... CUMBERLAND...GLOUCESTER AND SALEM COUNTIES... AT 905 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 10 MILES SOUTH OF WILMINGTON...MOVING EAST AT 21 MPH. THE THUNDERSTORM WILL BE NEAR WOODSTOWN...ALLOWAY AROUND 930 PM...ELMER...MULLICA HILL AROUND 945 PM...CLAYTON...GLASSBORO AROUND 1000 PM...WILLIAMSTOWN AND VICTORY LAKES AROUND 1015 PM. WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM. EXPECT INTENSE LIGHTNING FROM THIS STORM. DO NOT SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM APPROACHES. ADDITIONAL SHOWERS OR ISOLATED THUNDERSTORMS ARE POSSIBLE THROUGH 11 PM. NIERENBERG
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1003 PM EDT MON JUN 23 2008
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0731 PM TSTM WND DMG GRASONVILLE 38.96N 76.19W
06/23/2008 QUEEN ANNES MD COUNTY OFFICIAL
TREES AND WIRES DOWN
0750 PM TSTM WND DMG GRASONVILLE 38.96N 76.19W
06/23/2008 QUEEN ANNES MD COUNTY OFFICIAL
TREES AND WIRES DOWN
0757 PM TSTM WND DMG CENTREVILLE 39.04N 76.07W
06/23/2008 QUEEN ANNES MD COUNTY OFFICIAL
TREES AND WIRES DOWNED
&&SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 1033 PM EDT MON JUN 23 2008 PAZ060>062-067>069-240330- BERKS-BUCKS-CHESTER-LEHIGH-MONTGOMERY-NORTHAMPTON- 1033 PM EDT MON JUN 23 2008 ...STRONG THUNDERSTORMS WILL AFFECT BERKS...BUCKS... CHESTER...LEHIGH...MONTGOMERY AND NORTHAMPTON COUNTIES... AT 1031 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 18 MILES NORTHWEST OF READING...MOVING NORTHEAST AT 26 MPH. THE THUNDERSTORM WILL BE NEAR STRAUSSTOWN...BERNVILLE AROUND 1045 PM...HAMBURG...CENTERPORT AROUND 1100 PM... LENHARTSVILLE...FLEETWOOD AROUND 1115 PM...WANAMAKERS AND NEW TRIPOLI AROUND 1130 PM. WIND GUSTS TO 40 MPH ARE POSSIBLE WITH THIS STORM. EXPECT INTENSE LIGHTNING FROM THIS STORM. DO NOT SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM APPROACHES. NIERENBERG
The Philadelphia radar (KDIX), 133 km away, was scanning. The volume nearest the first event began at 03:06 UTC.
3 thunderstorm wind. Local standard time, as filed.
A severe thunderstorm tore down several large tree limbs and a couple of trees in Lower Alsace and Exeter Townships.
A severe thunderstorm knocked down a few trees in and around the Pottstown and Spring City.
The gust front from the severe thunderstorm in Montgomery County knocked over a few trees and wires in Schuylkill and East Vincent Townships.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2008Every state in 2008This day in weather historyWarnings in Pennsylvania, June 2008
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: 114604, 114605, 114606.