A long-lived and well-defined thunderstorm complex moved east from central Ohio and crossed southwest and south-central Pennsylvania during the early evening. The leading edge of the thunderstorm complex produced isolated damaging winds in Cambria County.
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 CTP wrote it up.
A long-lived and well-defined thunderstorm complex moved east from central Ohio and crossed southwest and south-central Pennsylvania during the early evening. The leading edge of the thunderstorm complex produced isolated damaging winds in Cambria County.
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 State College, PA wrote its last area forecast discussion before the first event at Jul 11, 5:02 PM EST, 28 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 602 PM EDT MON JUL 11 2011 .SYNOPSIS... A COLD FRONT WILL PUSH SOUTHEAST ACROSS PENNSYLVANIA TONIGHT AND EARLY TUESDAY. THERE IS A CHANCE OF SHOWERS AND STORMS TONIGHT... MAINLY ACROSS WESTERN SECTIONS. A CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE NORTHEAST CONUS DURING THE LATER HALF OF THE WEEK AND REMAIN PARKED OVER THE REGION INTO EARLY FRIDAY. HEAT AND HUMIDITY WILL RETURN TO THE BY LATE FRIDAY...AS THE HIGH MOVES OFF THE COAST. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... SEVERE THUNDERSTORM WATCH 631 ISSUED FOR THE NORTHERN END O THE DERECHO MOVING INTO THE LAURELS. CIRRUS SHIELD CONTINUES TO OVERSPREAD THE AREA PUTTING A BRAKE ON CONTINUED DESTABILIZATION...BUT SUFFICIENT INSTABILITY IN PLACE TO FUEL THE STORMS AS THEY RACE EASTWARD. MAIN THREAT WILL BE ISOLATED SEVERE GUSTS AS THE LINE SPEEDS EAST. CLOUD COVER AND HIGH HUMIDITY SHOULD KEEP TEMPS FROM FALLING ANY LOWER THAN THE L/M70S OVER MOST OF THE AREA TONIGHT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/... DID ADJUST POPS EARLY ON...BASED ON CHANGES MADE TO THE OVERNIGHT PERIOD. SCT TSRA WILL REMAIN POSSIBLE ACROSS THE S TIER EARLY TUESDAY AS FRONT CROSSES THE REGION. HOWEVER...BULK OF MDL DATA INDICATES A DRY AFTERNOON...AS SFC RIDGING AND DRIER AIR FILTER IN BEHIND FRONT. 850 TEMPS NR 20C AND LINGERING HIGH HUMIDITY WILL LIKELY PUSH HEAT INDICES TO ARND 100F ACROSS THE LOWER SUSQ. LATER SHIFTS MAY EVENTUALLY NEED TO ISSUE A HEAT ADVISORY...AS APPARENT TEMPS NEAR THE MD BORDER TOP OUT AROUND 100F FOR A FEW HOURS TUESDAY AFTERNOON. && .LONG TERM /TUESDAY NIGHT THROUGH MONDAY/... NO MAJOR CHANGES MADE TO THE PACKAGE...OTHER THAN TO ADD SLIGHT CHC POPS TO WED. A STRONG UPPER LVL JET MAX AND MAIN PUSH OF COOLER AIR WORKS IN LATER IN THE DAY ON WED...NORTHERN AREAS HAVE THE BEST CHC...BUT WENT 15 PERCENT ALL AREAS. STILL A CHC OF A SHOWER OR STORM LATER FRIDAY INTO SAT...GIVEN WEAKNESS ALOFT AND WARM ADVECTION. RISING HEIGHTS AFTER THIS SHOULD CAP ANY CONVECTION. TEMPS A LITTLE BELOW NORMAL THU AND FRIDAY...BUT BACK ABOVE NORMAL BY LATE IN THE WEEKEND. && .AVIATION /22Z MONDAY THROUGH SATURDAY/... THE CONVECTIVE SYSTEM CURRENTLY PUSHING THROUGH OHIO WILL MOVE INTO CENTRAL PENNSYLVANIA DURING THE EARLY EVENING HOURS. THE SYSTEM IS SLOWLY FALLING APART AS IT MOVES INTO DRIER AIR...BUT THERE IS STILL A CHANCE OF VCTS/VCSH AT ALL SITES... WHICH COULD BRING BRIEF MVFR CONDITIONS. SKIES WILL CLEAR OVERNIGHT AS A HIGH BUILDS OVER THE REGION. AREAS OF REDUCED VISIBILITY RESULTING FROM PATCHY MORNING FOG ARE POSSIBLE...ESPECIALLY IN AREAS THAT SEE RAIN THIS EVENING. EXPECT MAINLY VFR CONDITIONS THROUGH FRIDAY AS HIGH PRESSURE DOMINATES ACROSS THE REGION. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && SYNOPSIS...DEVOIR/LA CORTE/MARTIN NEAR TERM...DEVOIR/LA CORTE/MARTIN SHORT TERM...DEVOIR/MARTIN LONG TERM...MARTIN AVIATION...COLBERT
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 550 PM EDT MON JUL 11 2011 PAZ005-006-011-012-018-019-028-037-041-042-045-046-049>053-056>059- 063>066-122200- MCKEAN-POTTER-CAMERON-NORTHERN CLINTON-NORTHERN CENTRE- SOUTHERN CENTRE-JUNIATA-TIOGA-NORTHERN LYCOMING-SULLIVAN- SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER-MONTOUR- NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-CUMBERLAND- ADAMS-YORK-LANCASTER- 550 PM EDT MON JUL 11 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT. THE PROBABILITY OF WIDESPREAD SEVERE WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PAZ025>027-034>036-122200- BLAIR-HUNTINGDON-MIFFLIN-BEDFORD-FULTON-FRANKLIN- 550 PM EDT MON JUL 11 2011 ...SEVERE THUNDERSTORM WATCH 631 IN EFFECT UNTIL 11 PM EDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. SEVERE THUNDERSTORM WATCH. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PAZ004-010-017-122200- WARREN-ELK-CLEARFIELD- 550 PM EDT MON JUL 11 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT. THE PROBABILITY OF WIDESPREAD SEVERE WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PAZ024-033-122200- CAMBRIA-SOMERSET- 550 PM EDT MON JUL 11 2011 ...SEVERE THUNDERSTORM WATCH 631 IN EFFECT UNTIL 11 PM EDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. SEVERE THUNDERSTORM WATCH. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. 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 STATE COLLEGE PA
538 PM EDT MON JUL 11 2011
PAZ024-025-033-034-112230-
BEDFORD PA-BLAIR PA-CAMBRIA PA-SOMERSET PA-
538 PM EDT MON JUL 11 2011
...STRONG THUNDERSTORMS WILL AFFECT CAMBRIA...SOMERSET...WESTERN
BEDFORD AND WESTERN BLAIR COUNTIES...
A LINE OF STRONG THUNDERSTORMS WILL BE MOVING INTO CAMBRIA AND
SOMERSET COUNTIES BY 500 PM EDT AND BEDFORD AND BLAIR COUNTIES BY 6
PM. THE STRONG THUNDERSTORMS WERE GENERALLY MOVING EAST AT 40 MPH.
WIND GUSTS TO 50 MPH ARE POSSIBLE WITH THESE STRONG THUNDERSTORMS.
EXPECT INTENSE LIGHTNING FROM THESE STRONG THUNDERSTORMS. DO NOT STAY
IN THE OPEN NOR SEEK SHELTER UNDER TREES WHEN LIGHTNING THREATENS...
MOVE INDOORS WHEN A THUNDERSTORM APPROACHES. VERY HEAVY RAIN WILL
FALL FROM THESE STRONG THUNDERSTORMS...AND WILL CAUSE WATER TO POND
ON ROADS AND FILL POOR DRAINAGE AREAS. THE RAIN WILL CAUSE RAPID
RISES ON SMALL STREAMS AND CREEKS.
THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...THE
PENNSYLVANIA TURNPIKE BETWEEN MILE MARKERS 100 AND 138...I-99 NEAR
MILE MARKER 29.
THIS WILL ALSO IMPACT THE FOLLOWING MAJOR ROADS...THE JOHNSTOWN
EXPRESSWAY...ROUTE 22...ROUTE 30...ROUTE 40...ROUTE 219...ROUTE
422...STATE ROAD 56.
LAT...LON 3971 7939 3974 7941 3982 7937 3985 7942
3990 7941 4009 7926 4012 7921 4013 7918
4036 7900 4070 7883 4070 7831 3972 7875
FORECASTER: CERUThe State College radar (KCCX), 104 km away, was scanning. The volume nearest the first event began at 22:32 UTC.
1 thunderstorm wind. Local standard time, as filed.
Thunderstorm winds estimated near 60 mph knocked down trees and utility wires near Westmont.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2011Every state in 2011This day in weather historyWarnings in Pennsylvania, July 2011
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: 312652.