An upper air disturbance helped trigger a severe thunderstorm during the afternoon of the 18th in the Lehigh Valley.
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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.
An upper air disturbance helped trigger a severe thunderstorm during the afternoon of the 18th in the Lehigh Valley.
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 18, 2:05 PM EST, 1 hour 31 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 305 PM EDT WED JUN 18 2008 .SYNOPSIS... A TROUGH OVER THE EASTERN UNITED STATES WILL REMAIN IN PLACE THROUGH EARLY NEXT WEEK. SEVERAL DISTURBANCES WILL ROTATE THROUGH THE TROUGH AND WILL KEEP CHANCES OF SHOWERS AND THUNDERSTORMS EACH DAY. A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS WILL OCCUR SUNDAY INTO EARLY MONDAY AS AN AREA OF LOW PRESSURE MOVES FROM THE SOUTHEASTERN STATES TO NEW ENGLAND AND A COLD FRONT CROSS THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AN UPPER LEVEL LOW OVER CANADA AND LINGERING UPR TROF WILL REMAIN IN PLACE AND AT LEAST ONE STRONG VORT IS FCST TO MOVE ACRS THE REGION. LATEST RADAR IMAGERY SHOWS FAIRLY ORGANIZED SHOWERS AND TSTMS IN CNTRL AND WRN PA AND LESS ORGANIZED ACTIVITY IN ERN PA AND NRN NJ. ANY TSTMS COULD PRODUCE GUSTY WINDS, HEAVY RAIN AND SMALL HAIL. LATEST MODEL DATA HAS A WK BNDRY FCST TO MOVE THRU BY 00Z OR SHORTLY THEREAFTER AND THE VORT MOVG THRU THIS EVENING AS WELL. PRECIP CHCS WILL CONTINUE UNTIL THESE FEATURES MOVE THRU. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... SAME SONG, SLIGHTLY DIFFERENT VERSE...THE PERSISTENT WX PATTERN CONTINUES WITH THE UPR TROF OVER THE ERN CONUS. HOWEVER, THERE DOES NOT APPEAR TO BE ANY SIG S/WVS OR OTHER FOCUSING MECHANISMS FOR SHOWERS/TSTMS ON THURSDAY OR THURSDAY NIGHT. HOWEVER, WITH THE COLD AIR ALOFT, DUE TO THE UPPER RIDGE, CERTAINLY CAN NOT RULE OUT A DIURNAL SHWR OR TSTM BUT THINK OVERALL AREAL COVERAGE ON THURSDAY WILL BE FAIRLY LIMITED. WITH ABUNDANT CLOUD COVER AND CYCLONIC FLOW EXPECTED AGAIN, TEMPS SHUD REMAIN BLO NORMAL AND MOS GUID LOOKS REASONABLE. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... THE UPPER LEVEL TROUGH WILL REMAIN OVER THE AREA INTO EARLY NEXT WEEK. THE TROF WILL GRADUALLY FLATTEN OUT OVER THE WEEKEND, AS HIGH PRESSURE BUILDS TO THE SOUTH. HOWEVER, THE TROUGH WILL RE-AMPLIFY LATE SUNDAY THROUGH TUESDAY AS A SFC LOW DEVELOPS OVER THE SERN STATES ON SUNDAY AND MOVES INTO NEW ENG EARLY MONDAY. THE COLD FRONT ASSOCIATED WITH THE LOW WILL CROSS THE REGION ON MONDAY WITH A SECONDARY FRONT ON TUESDAY. BEHIND THIS FRONT, THE PERSISTENT UPR TROF WILL FINALLY BEGIN TO MOVE EWD AND OUT OF THE AREA BY MIDWEEK. DUE TO THE PROXIMITY OF THE UPPER TROF, THE EARLY PART OF THE PERIOD WILL FEATURE SOME LOW PRECIP CHANCES, MAINLY FOR DIURNAL SHOWERS/TSTMS WITH DAYTIME HEATING AND UPPER LEVL INSTABILITY. THE BEST CHANCE FOR PRECIP APPEARS TO BE FROM SUNDAY AFTERNOON INTO EARLY MONDAY AS THE AFOREMENTIONED SFC LOW AND CDFNT MOVE ACROSS THE REGION. LOW PRECIP CHCS WILL CONTINUE INTO TUESDAY, WITH THE SECONDARY FRONT, BEFORE HIGH PRESSURE STARTS TO BUILD IN FROM THE S AND W. TEMPS LOOK TO BE AT OR SLIGHTLY ABV SEASONAL NORMS THRU THE PD AND MOS GUID WAS GENERALLY ACCEPTED. && .AVIATION /17Z WEDNESDAY THROUGH SUNDAY/... DESTABILIZATION, ALONG WITH AN ADVANCING SHORT WAVE, IS BRINGING CLOUDS AND SCATTERED SHOWERS INTO THE AREA. HAVE INCLUDED A CB CLOUD GROUP IN THE AFTERNOON AND EARLY EVENING HOURS AT ALL TAF SITES TO ACCOUNT FOR ANY THUNDERSTORM ACTIVITY THAT MAY PASS BY. HAVE ALSO INCLUDED A VCSH FROM EARLY EVENING INTO THE LATE EVENING HOURS TO ACCOUNT FOR ANY LINGERING SHOWER ACTIVITY. BASICALLY VFR CONDITIONS THEN EXPECTED FROM LATE TONIGHT INTO THU AFTERNOON AS SLIGHTLY DRIER AIR MOVES IN OVER THE REGION. OUTLOOK... MAINLY DRY WEATHER AND VFR CONDITIONS ARE EXPECTED FROM THURSDAY AFTERNOON INTO SATURDAY. WEAK LOW PRESSURE DEVELOPING OVER THE MID ATLANTIC REGION MAY BRING SOME SHOWERS TO PARTS OF OUR REGION DURING THE LATTER HALF OF THE WEEKEND. && .MARINE... LOW PRESSURE LOCATED OVER QUEBEC WILL PERSIST INTO THE WEEKEND. A SERIES OF WEAK FRONTS ASSOCIATED WITH THIS LOW WILL CROSS THE FORECAST WATERS INTO SATURDAY. AN AREA OF LOW PRESSURE COULD DEVELOP OVER THE MID ATLANTIC REGION EARLY SUNDAY. WIND SPEED AND WIND DIRECTION WILL VARY BETWEEN W AND S DURING THE FORECAST PERIOD. WIND SPEEDS SHOULD REMAIN MOSTLY IN THE 10 KNOT OR LESS RANGE, BUT HIGHER SPEEDS ARE POSSIBLE LATE SATURDAY INTO MONDAY DEPENDING ON IF AND WHERE A LOW PRESSURE SYSTEM HAPPENS TO DEVELOP. SEAS COULD APPROACH 5 FT ON SUNDAY, AGAIN DEPENDING ON THE CHARACTERISTICS OF THIS POSSIBLE LOW. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && SYNOPSIS...NIERENBERG NEAR TERM...NIERENBERG SHORT TERM...NIERENBERG LONG TERM...NIERENBERG AVIATION...MIKETTA MARINE...MIKETTA
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 334 AM EDT WED JUN 18 2008 DEZ001>004-MDZ008-012-015-019-020-NJZ001-007>010-012>027-PAZ054-055- 060>062-067>071-190745- 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- 334 AM EDT WED JUN 18 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL DELAWARE...NORTHERN DELAWARE...SOUTHERN DELAWARE...EASTERN MARYLAND...NORTHEAST MARYLAND...CENTRAL NEW JERSEY...NORTHERN NEW JERSEY...SOUTHERN NEW JERSEY...EAST CENTRAL PENNSYLVANIA...NORTHEAST PENNSYLVANIA AND SOUTHEAST PENNSYLVANIA. .DAY ONE...TODAY AND TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON. ANY THUNDERSTORM THAT DEVELOPS MAY HAVE GUSTY WINDS OR SOME SMALL HAIL. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. ANZ430-431-450>455-190745- 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- 334 AM EDT WED JUN 18 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS AND DELAWARE BAY WATERS. .DAY ONE...TODAY AND TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON. ANY THUNDERSTORM THAT DEVELOPS MAY HAVE GUSTY WINDS OR SOME SMALL HAIL. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 155 PM EDT WED JUN 18 2008 NJZ001-008-181900- MORRIS-SUSSEX- 155 PM EDT WED JUN 18 2008 ...A STRONG THUNDERSTORM WILL AFFECT MORRIS AND SUSSEX COUNTIES... AT 148 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 33 MILES NORTHWEST OF PATERSON...MOVING EAST AT 14 MPH. THE THUNDERSTORM WILL BE NEAR OGDENSBURG AROUND 210 PM... SUSSEX...FRANKLIN AROUND 215 PM...HAMBURG AROUND 220 PM...LAKE TELEMARK AROUND 230 PM...GREEN POND AROUND 235 PM AND BOONTON AROUND 250 PM. WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM. RNS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 325 PM EDT WED JUN 18 2008 PAZ054-060-061-181945- BERKS-CARBON-LEHIGH- 325 PM EDT WED JUN 18 2008 ...A STRONG THUNDERSTORM WILL AFFECT BERKS...CARBON AND LEHIGH COUNTIES... AT 318 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 22 MILES NORTH OF READING...MOVING EAST AT 33 MPH. THE THUNDERSTORM WILL BE NEAR NEW TRIPOLI AROUND 335 PM AND EMERALD AROUND 345 PM. WIND GUSTS TO 40 MPH...SMALL HAIL AND A BRIEF PERIOD OF HEAVY RAIN ARE POSSIBLE WITH THIS STORM. RNS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 333 PM EDT WED JUN 18 2008 PAZ067-070-182000- CHESTER-DELAWARE- 333 PM EDT WED JUN 18 2008 ...A STRONG THUNDERSTORM WILL AFFECT CHESTER AND DELAWARE COUNTIES... AT 330 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 15 MILES NORTH OF NEWARK...MOVING EAST AT 23 MPH. THE THUNDERSTORM WILL BE NEAR MARSHALLTON...DOWNINGTOWN AROUND 345 PM...WESTTOWN AND CHEYNEY AROUND 400 PM. WIND GUSTS TO 40 MPH...SMALL HAIL AND A BRIEF PERIOD OF HEAVY RAIN ARE POSSIBLE WITH THIS STORM. RNS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 356 PM EDT WED JUN 18 2008 NJZ010-012-182030- MIDDLESEX-SOMERSET- 356 PM EDT WED JUN 18 2008 ...A STRONG THUNDERSTORM WILL AFFECT MIDDLESEX AND SOMERSET COUNTIES... AT 348 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 5 MILES WEST OF NEW BRUNSWICK...MOVING EAST AT 20 MPH. THE THUNDERSTORM WILL BE NEAR EDISON...FORDS AROUND 415 PM... PERTH AMBOY AND WOODBRIDGE AROUND 430 PM. WIND GUSTS TO 40 MPH...SMALL HAIL AND A BRIEF PERIOD OF HEAVY RAIN ARE POSSIBLE WITH THIS STORM. LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING. MOVE TO SAFE SHELTER IMMEDIATELY. RNS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 400 PM EDT WED JUN 18 2008 PAZ067-068-070-071-182045- CHESTER-DELAWARE-MONTGOMERY-PHILADELPHIA- 400 PM EDT WED JUN 18 2008 ...A STRONG THUNDERSTORM WILL AFFECT CHESTER...DELAWARE...MONTGOMERY AND PHILADELPHIA COUNTIES... AT 354 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 13 MILES NORTH OF WILMINGTON...MOVING EAST AT 26 MPH. THE THUNDERSTORM WILL BE NEAR GRADYVILLE...UPPER PROVIDENCE TOWNSHIP AROUND 415 PM...MORRIS PARK...MILLBOURNE AROUND 430 PM... TEMPLE UNIVERSITY AND CENTER CITY AROUND 445 PM. WIND GUSTS TO 40 MPH...SMALL HAIL AND A SHORT PERIOD OF HEAVY RAIN ARE POSSIBLE WITH THIS STORM. LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING. MOVE TO SAFE SHELTER IMMEDIATELY. RNS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 402 PM EDT WED JUN 18 2008 NJZ001-008-182030- MORRIS-SUSSEX- 402 PM EDT WED JUN 18 2008 ...A STRONG THUNDERSTORM WILL AFFECT MORRIS AND SUSSEX COUNTIES... AT 354 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 32 MILES NORTHEAST OF BETHLEHEM...MOVING NORTHEAST AT 40 MPH. THE THUNDERSTORM WILL BE NEAR FIVE POINTS... PELLETTOWN AROUND 415 PM...HAMBURG AND SUSSEX AROUND 430 PM. WIND GUSTS TO 40 MPH...SMALL HAIL AND A SHORT PERIOD OF HEAVY RAIN ARE POSSIBLE WITH THIS STORM. LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS. REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING. MOVE TO SAFE SHELTER IMMEDIATELY. RNS
The national radar mosaic for the moment the first event began.
1 thunderstorm wind. Local standard time, as filed.
A severe thunderstorm tore down large tree limbs and wires in Macungie and Upper Saucon Township.
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: 114601.