An approaching warm front helped produce severe thunderstorms and also caused some lightning damage across northern Delaware.
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.
An approaching warm front helped produce severe thunderstorms and also caused some lightning damage across northern Delaware.
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 Jul 27, 2:00 PM EST, 5 hours 10 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 300 PM EDT FRI JUL 27 2007 .SYNOPSIS... THE AIRMASS OVER THE NEXT NEXT SEVERAL DAYS WITH BE VERY WARM AND HUMID WITH HEAVY RAIN AND THE POTENTIAL FOR STRONG THUNDERSTORMS. AS A FRONTAL BOUNDARY WILL REMAIN OVER THE REGION THROUGH THE WEEKEND AS AN LOW MOVES EAST INTO NEW YORK STATE BY SATURDAY EVENING. && .NEAR TERM /THROUGH TONIGHT/... TEMPERATURES THIS AFTERNOON CLIMBING THROUGH THE 80S AND MAY EVEN HIT 90 FOR A SHORT TIME THIS AFTERNOON. SO FAR THIS JULY HAVE ONLY REACHED 90 FIVE TIMES IN PHL. SEVERE WEATHER TO OUR WEST ATTM MAY BE SHIFTING EAST WITH SOME NEW CELLS FORMING RIGHT OVER THE CWA. WW555 BUTTS UP AGAINST OUR WESTERN ZONES AND, GIVEN THE DESTABILIZING ATMOSPHERE OVER US, MAY BE EXTENDED FARTHER EAST OR THE SVR THREAT BECOMES A LOCALIZED FLOOD THREAT. THE SHORT WAVE IGNITING THE STORMS TO THE WEST WILL ROTATE NORTHEAST AND BE OVER THE DELAWARE VALLEY BY 00Z AND INTO NORTH JERSEY BY 06Z. OTHER SHOWERS AND THUNDERSTORMS ARE FORMING ON THE SEABREEZE FRONT OVER NJ AND DEL AND WILL PRODUCE SOME GOOD LOCALIZED RAINS, BEFORE THE MAIN THRUST COMES THROUGH THIS EVENING. THE K VALUES ON THE GFS REACH 40 CERTAINLY INDICATIVE OF A HEAVY RAIN EVENING THIS EVENING. STRONG GRADIENT EXISTS TO THE COAST WITH 28 OFF THE NJ COAST WHICH IS AT THE TSTM THRESHOLD. PWS ARE AT OR SLIGHTLY ABOVE 2 INCHES. IN THIS ENVIRONMENT, THAT TRANSLATES TO 4 INCHES OF RAIN IN SOME AREAS. THE DEW POINTS ARE IN THE MID 60S SOUTHERN POCONOS AND NEAR 70 MOST OTHER AREAS. JUST OFFSHORE, 44009 HAS A DEW POINT OF 76 WITH WINDS DIRECTED ONSHORE. WITH THE WATER TEMPERATURES AVERAGING THEIR HIGHEST SO FAR SINCE JUNE 1 ALONG THE NJ AND DELAWARE COASTS(MID 70S)THERE IS PLENTY OF MOISTURE CONTRIBUTING TO AN EXTENDED THREE-FOUR DAY PERIOD OF VERY HUMID CONDITIONS AND THE POTENTIAL FOR HEAVY RAIN. A STATIONARY FRONT WILL SET UP ALONG THE DELAWARE VALLEY AND BE THE FOCUS OF PRECIPITATION THROUGH THIS EVENING AND AGAIN ON TONIGHT. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... THE ONLY SIGNIFICANT CHANGE THROUGH SUNDAY WILL BE THE MOVEMENT OF THE UPPER LOW WHICH BECOMES AN OPEN SATURDAY NIGHT. RIDGE IN THE WEST BUILDS SLIGHTLY NORTH WHICH IS KEEPING THE TROUGH IN PLACE OVER THE EASTERN U.S. THROUGH SUNDAY NIGHT. SHOWERS AND THUNDERSTORMS CONTINUE IN OUR CWA AND THE AIRMASS REMAINS VERY UNSTABLE. LOWS TONIGHT INTERIOR SECTIONS WILL DROP INTO THE MID 60S BUT REMAIN UP A FEW DEGREES ALONG THE COAST WITH SOUTHEAST WINDS OFF THE OCEAN. A TONGUE OF 90 DEGREE TEMPERATURES WILL BE LOCATED FROM NORTHEAST MARYLAND THROUGH NORTHERN DELAWARE AND MAY JUST REACH PHL. A FRESH SOUTHEAST WIND FROM THE DELAWARE BAY WILL HOLD THOSE TEMPERATURES FROM GETTING TOO MUCH HIGHER. THE MAIN CONCERN ON SATURDAY WILL BE HOW MUCH INTERACTION THERE WILL BE FROM OUTFLOW BOUNDARY FROM TODAYS ACTIVITY AND THE DEVELOPING SEABREEZE. GFS SHOWS A PRONOUNCED VORT MAX TAIL EXTENDING DOWN JUST EAST OF THE DELAWARE RIVER AT THE PEAK HEATING OF THE DAY. 50H TEMPERATURES ARE SLIGHTLY COOLER(-9.8) AND LIS OF -4, K-VALUES OF 34-36 FROM NORTH JERSEY DOWN TO SOUTHERN DELAWARE. WEAK SURFACE CONVERGENCE ALL POINT TO A LOCALIZED HEAVY RAIN EVENT IN NEW JERSEY. LOWS SATURDAY NIGHT A FEW DEGREES HIGHER INTO THE LOW TO MID 70S IN THE MAJOR METRO AREAS AND MID 60S IN THE SOUTHERN POCONOS. && .LONG TERM /MONDAY THROUGH THURSDAY/... AS THE RIDGE CONTINUES TO SLOWLY BUILD ALONG THE FRONT RANGE, THE UPPER LOW MAY CLOSE OFF AGAIN OVER PENNSYLVANIA SUNDAY NIGHT BEFORE DRIFTING SOUTHEAST TO THE DELMARVA BY MONDAY NIGHT. THE RIDGE MAKES VERY LITTLE PROGRESS IF YOU FOLLOW THE 576 THICKNESS CONTOUR AS IT IS SUPPRESSED TO THE SOUTH THEN INTO THE WESTERN GREAT LAKES. WE NEVER DO GET INTO EXTENDED REAL HOT WEATHER FOR THE FORESEEABLE FUTURE, BUT IT WILL REMAIN HUMID. THERE IS AN INTERESTING PAPER BY GALARNEAU/BOSART ET AL ON CLIMATOLOGY OF THICKNESS HIGHS AND LOWS. THE GFS TRIES TO SPIN UP A COASTAL LOW BY TUESDAY BUT THIS HAS BEEN DISMISSED FOR THE TIME BEING AS NOTHING ATTM SUPPORTS THIS SYSTEM SLOWLY DOWN. OTHERWISE CLIMATOLOGY PRETTY MUCH SAYS IT TEMPERATURE WISE AND REMAINING ON THE HUMID SIDE WITH A CHANCE OF SHOWERS AND TSTMS FROM TIME TO TIME. BUT THEN AGAIN, IT IS SUMMER && .AVIATION /17Z FRIDAY THROUGH TUESDAY/... .AVIATION /BE SURE TO INCLUDE THE OUTLOOK/... AN UNSTABLE AIRMASS REMAINS OVER THE REGION AND TODAYS DAYTIME HEATING WILL JUST MAKE THE AIRMASS MORE UNSTABLE THIS AFTN. TSTMS HAVE ALREADY BROKEN OUT IN CENTRAL PA SW TO WRN MD AND WV WITH A SVR TSTMS WATCH IN THAT AREA. THERE IS THE POSSIBILITY OF SVR TSTMS AT ANY OF THE TAF SITES THIS AFTN AS THE AREA OF TSTMS TO THE WEST PROGRESSES EAST AND MOVES/DVLPS OVER THE REGION. THE MOST LIKELY TIME FOR TSTMS IS 20Z-24Z. HOWEVER, EVEN BEFORE 20Z, ISOLATED TSTMS WERE DEVELOPING ALONG SEABREEZES AND BAYBREEZES. ANY TSTMS THAT FORM COULD CONTAIN DAMAGING WINDS, AND TORRENTIAL DOWNPOURS AS WELL AS FREQUENT LIGHTNING. THE TSTMS SHOULD WEAKEN AFTER SUNSET AND DISSIPATE TOWARD MIDNIGHT. THEN LATE TONIGHT, I EXPECT A REDEVELOPMENT OF LOWER CLOUDS AND LIGHT FOG, SIMILAR TO WHAT HAPPENED THIS MORNING. FOR NOW, THE TAFS SHOW MVFR CONDITIONS OF 15 HND FT CIG AND 4 MI VSBY, BUT IFR CONDITIONS COULD ALSO DEVELOP. LATE SAT MRNG, A RETURN TO VFR CONDITIONS SHOULD OCCUR AS DAYTIME HEATING DISSIPATES ANY LOWER CLOUDS. && .MARINE... A BROAD SOUTH TO SOUTHEAST FLOW SHOULD CONTINUE OVER THE REGION THIS WEEKEND. THEN A COLD FRONT WILL DROP SLOWLY SOUTH THROUGH THE REGION MONDAY AFTERNOON AND NIGHT ALLOWING A WIND SHIFT TO THE NE. UNTIL THE FRONT MOVES THROUGH, THERE WILL BE THE CHC FOR SHOWERS AND TSTMS. AFTER FRONTAL PASSAGE, SHOWERS COULD LINGER INTO TUESDAY. WIND SPEEDS ARE EXPECTED TO REMAIN MOSTLY BELOW 15 KNOTS THROUGH THE PERIOD. THE PROLONGED NE FLOW FOR TUE AND WED COULD ALLOW SOME INCR IN THE SEAS, FOR NOW 4 FT WILL BE MENTIONED ON THE OCEAN. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...NONE. NJ...NONE. DE...NONE. MD...NONE. MARINE...NONE. && SYNOPSIS/NEAR-SHORT-LONG TERM...EBERWINE AVIATION/MARINE...RNS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 433 PM EDT FRI JUL 27 2007 DEZ003-004-NJZ013-014-020-022>027-282045- INLAND SUSSEX-DELAWARE BEACHES-WESTERN MONMOUTH-EASTERN MONMOUTH- OCEAN-ATLANTIC-CAPE MAY-ATLANTIC COASTAL CAPE MAY-COASTAL ATLANTIC- COASTAL OCEAN-SOUTHEASTERN BURLINGTON- 433 PM EDT FRI JUL 27 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN DELAWARE...CENTRAL NEW JERSEY AND SOUTHERN NEW JERSEY. .DAY ONE...TONIGHT THE RIP CURRENT RISK FOR THE SOUTHERN HALF OF NEW JERSEY IS MODERATE. LIFE GUARDS REPORT SEVERAL RESCUES THIS AFTERNOON. SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON AND WILL BE ACCOMPANIED BY HEAVY RAIN, AND THERE IS ALSO A THREAT OF SOME OF THE STORMS BECOMING SEVERE. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. DEZ001-002-MDZ008-012-015-019-020-NJZ001-007>010-012-015>019-021- PAZ054-055-060>062-067>071-282045- NEW CASTLE-KENT DE-CECIL-KENT MD-QUEEN ANNES-TALBOT-CAROLINE-SUSSEX- WARREN-MORRIS-HUNTERDON-SOMERSET-MIDDLESEX-MERCER-SALEM-GLOUCESTER- CAMDEN-NORTHWESTERN BURLINGTON-CUMBERLAND-CARBON-MONROE-BERKS-LEHIGH- NORTHAMPTON-CHESTER-MONTGOMERY-BUCKS-DELAWARE-PHILADELPHIA- 433 PM EDT FRI JUL 27 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL DELAWARE...NORTHERN DELAWARE...EASTERN MARYLAND...NORTHEAST MARYLAND...CENTRAL NEW JERSEY...NORTHERN NEW JERSEY...SOUTHERN NEW JERSEY...EAST CENTRAL PENNSYLVANIA...NORTHEAST PENNSYLVANIA AND SOUTHEAST PENNSYLVANIA. .DAY ONE...TONIGHT SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON AND WILL BE ACCOMPANIED BY HEAVY RAIN, AND THERE IS ALSO A THREAT OF SOME OF THE STORMS BECOMING SEVERE. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. ANZ430-431-450>455-282045- 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- 433 PM EDT FRI JUL 27 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL WATERS AND DELAWARE BAY WATERS. .DAY ONE...TONIGHT NO HAZARDOUS WEATHER IS EXPECTED TONIGHT. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. EBERWINE
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 527 PM EDT FRI JUL 27 2007 PAZ060-272230- BERKS- 527 PM EDT FRI JUL 27 2007 ...A LINE OF STRONG THUNDERSTORMS WILL AFFECT BERKS COUNTY... AT 520 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE OF STRONG THUNDERSTORM 18 MILES WEST OF READING...MOVING EAST AT 15 MPH. THE THUNDERSTORM WILL BE NEAR ROBESONIA AROUND 535 PM... BERNVILLE AROUND 540 PM...CENTERPORT AROUND 600 PM... LEESPORT...SHOEMAKERSVILLE...HAMBURG AROUND 605 PM... TEMPLE...LAURELDALE AROUND 610 PM AND LENHARTSVILLE AROUND 620 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. SZATKOWSKI
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 549 PM EDT FRI JUL 27 2007 PAZ054-272245- CARBON- 549 PM EDT FRI JUL 27 2007 ...A STRONG THUNDERSTORM WILL AFFECT CARBON COUNTY... AT 541 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 26 MILES SOUTH OF WILKES-BARRE...MOVING EAST AT 20 MPH. THE THUNDERSTORM WILL BE NEAR WEATHERLY AROUND 555 PM...JIM THORPE...LEHIGHTON AROUND 605 PM...WEISSPORT EAST AROUND 610 PM... CHRISTMANS...BELTZVILLE STATE PARK AROUND 625 PM...PENN FOREST RESERVOIR AND ALBRIGHTSVILLE AROUND 635 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. PREVIOUS HEAVY RAINS HAVE FALLEN IN THE COUNTY EARLIER THIS AFTERNOON. PLEASE BE ON THE LOOKOUT FOR RAPIDLY RISING WATERS. WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM. SZATKOWSKI
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 629 PM EDT FRI JUL 27 2007 PAZ055-280000- MONROE- 629 PM EDT FRI JUL 27 2007 ...A STRONG THUNDERSTORM WILL AFFECT MONROE COUNTY... AT 623 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 24 MILES SOUTHEAST OF WILKES-BARRE...MOVING EAST AT 15 MPH. THE THUNDERSTORM WILL BE NEAR JONAS AROUND 640 PM...LONG POND...POCONO PINES AROUND 655 PM...REEDERS...MOUNT POCONO AROUND 715 PM...SCOTRUN AROUND 720 PM...PARADISE VALLEY AROUND 730 PM... ARLINGTON HEIGHTS...ANALOMINK AND HERNYVILLE AROUND 735 PM. 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. SZATKOWSKI
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 744 PM EDT FRI JUL 27 2007 NJZ001-007>009-280115- HUNTERDON-MORRIS-SUSSEX-WARREN- 744 PM EDT FRI JUL 27 2007 ...STRONG THUNDERSTORMS WILL AFFECT HUNTERDON...MORRIS...SUSSEX AND WARREN COUNTIES... AT 738 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 37 MILES EAST OF SCRANTON TO 12 MILES EAST OF BETHLEHEM...MOVING EAST AT 20 MPH. THE THUNDERSTORMS WILL BE NEAR MILFORD...BLAIRSTOWN AROUND 750 PM... PLEASANT VALLEY...HOPE...OXFORD...FRENCHTOWN AROUND 755 PM... WASHINGTON...HAMPTON AROUND 800 PM...HAINESVILLE AND FIVE POINTS AROUND 805 PM. WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THESE STORMS. VERY HEAVY RAINFALL WITH PONDING OF WATER ON ROADWAYS CAN ALSO BE EXPECTED. EXPECT INTENSE LIGHTNING FROM THESE STORMS. DO NOT SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM APPROACHES. SZATKOWSKI
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
749 PM EDT FRI JUL 27 2007
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0600 PM TSTM WND DMG STRAUSSTOWN 40.49N 76.18W
07/27/2007 BERKS PA COUNTY OFFICIAL
TREES AND POWER LINES DOWN
&&
EBERWINESPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE MOUNT HOLLY NJ 805 PM EDT FRI JUL 27 2007 PAZ068>071-280200- BUCKS-DELAWARE-MONTGOMERY-PHILADELPHIA- 805 PM EDT FRI JUL 27 2007 ...STRONG THUNDERSTORMS WILL AFFECT BUCKS...DELAWARE...MONTGOMERY AND PHILADELPHIA COUNTIES... AT 759 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 13 MILES EAST OF BETHLEHEM TO 10 MILES NORTHWEST OF WILMINGTON...MOVING EAST AT 20 MPH. THE THUNDERSTORMS WILL BE NEAR ELAM...CHEYNEY...BEDMINSTER... FRICKS AROUND 810 PM...CONCORDVILLE...GRADYVILLE...PIPERSVILLE... LANSDALE AROUND 815 PM...TINICUM AND NORTH WALES AROUND 820 PM. WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THESE STORMS. VERY HEAVY RAINFALL CAN ALSO BE EXPECTED WITH THESE STORMS. EXPECT INTENSE LIGHTNING FROM THESE STORMS. DO NOT SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS...MOVE INDOORS WHEN A THUNDERSTORM APPROACHES. SZATKOWSKI
The national radar mosaic for the moment the first event began.
1 lightning, 1 thunderstorm wind. Local standard time, as filed.
The combination of lightning strikes and damaging winds caused about 5,200 homes and businesses to lose power across New Castle County.
Severe thunderstorms tore down a few trees and wires across northern New Castle County from Prices Corner in Christina Hundred eastward. The combination of lightning and damaging winds caused about 5,200 homes and businesses in New Castle County to lose power.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Delaware in 2007Every state in 2007This day in weather historyWarnings in Delaware, July 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: 51469, 51471.