A mid-level disturbance located over central Pennsylvania along with a corridor of instability and ascent along and in the lee of the Appalachians ahead of a low pressure trough moving eastward from the Upper Ohio Valley contributed to the development of isolated severe thunderstorms. Localized wind damage and marginally severe hail was reported in Clearfield, Centre and Franklin Counties.
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 mid-level disturbance located over central Pennsylvania along with a corridor of instability and ascent along and in the lee of the Appalachians ahead of a low pressure trough moving eastward from the Upper Ohio Valley contributed to the development of isolated severe thunderstorms. Localized wind damage and marginally severe hail was reported in Clearfield, Centre and Franklin Counties.
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 Aug 14, 2:53 PM EST, 57 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 353 PM EDT SUN AUG 14 2011 .SYNOPSIS... A DEEP UPPER LEVEL TROUGH WILL DOMINATE THE WEATHER OVER OUR REGION FOR THE NEXT FEW DAYS PRODUCING TIMES OF SHOWERS AND THUNDERSTORMS THROUGH MONDAY. THE HEAVIEST RAINFALL SHOULD BE TO OUR EAST. THE UPPER TROUGH WEAKENS TOWARD THE MIDDLE OF THE WEEK BEFORE ANOTHER SURGE OF NORTHERN STREAM ENERGY REINFORCES THIS AUTUMN-LIKE TROUGH LATER NEXT WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 700-850 MB DEFORMATION HAS SHIFTED NORTHWARD THIS AFTERNOON TAKING THE LARGE AREA OF MODERATE TO LOCALLY HEAVY RAINFALL INTO NY STATE AND THE POCONO PLATEAU REGION...AS WELL AS THE MIDDLE TO LOWER SUSQUEHANNA RIVER VALLY. RADAR PRECIPITATION ESTIMATES OF 2 TO 3 INCHES IN SOME AREAS WITH MINOR FLOODING CONCERNS...BUT OVERALL CENTRAL PA HAS COME THROUGH UNSCATHED TO THIS POINT. AS THE UPPER LOW CIRCULATION APPROACHES FROM OHIO...LOW TOPPED OPEN CELLULAR CONVECTION HAS DEVELOPED OVER WESTERN PA AND WILL AFFECT CENTRAL AND WESTERN AREAS THIS AFTERNOON AND EVENING. OVERALL POPS IN GOOD SHAPE...AS IS THE DISTRIBUTION OF QPF FAVORING EASTERN AND NORTHERN AREAS EARLY TONIGHT. MINOR FLOODING IS MOST LIKELY ACROSS FAR EASTERN AREAS...WHERE SMALL STREAM RESPONSES WILL BE APPRECIATIVE BUT ARE EXPECTED TO REMAIN BELOW FLOOD AT THIS TIME. STILL A MINOR SEVERE WEATHER THREAT THIS EVENING ALONG THE MD BORDER WHERE SUNBREAKS CONTINUE...BUT IT DOES NOT APPEAR THAT CAPE WILL BE SUBSTANTIAL ENOUGH FOR WIDESPREAD SEVERE WEATHER THREAT THIS EVENING. DECREASING SHOWER ACTIVITY EXPECTED AFTER THE DIURNAL MAXIMUM AS THE UPPER LOW DROPS OVER WV AND SFC AND 850 MB TROF BECOME SITUATION OVER ERN PA AND NEW JERSEY. THIS WILL KEEP AT LEAST CHC POPS IN PLACE OVERNIGHT ALONG WITH AREAS OF MAINLY LIGHT FOG. LOWS TONIGHT MAINLY IN THE 60S AND HIGHS MONDAY IN THE 70S. && .SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/... HEAVY RAIN FOCUS THROUGH MONDAY WILL BE ALONG THE EASTERN SEABOARD... WELL EAST OF CENTRAL PA...AS ANOMALOUS PW PLUME 2" OR GREATER REMAINS ALIGNED FROM DELAWARE TO COASTAL NEW JERSEY. SOME BACKING OF THE DEEPER PW IS LIKELY ON MONDAY...WITH EASTERLY FLOW OFF OF THE ATLANTIC HELPING TO KEEP LIKELY TO CATEGORICAL POPS OVER EASTERN AREAS MON AFTN. FOR MOST OF CENTRAL PA...LIGHTER PRECIP IN THE FORM OF SCT SHRA/TSRA WILL ACCOMPANY PASSAGE OF UPPER LVL TROF. LITTLE DIURNAL TEMP RANGE EXPECTED DUE TO CLOUD COVER AND ABUNDANT LOW LVL MOISTURE. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... RATHER STRONG UPPER LEVEL LOW OVER WESTERN LAKE ERIE EARLIER... NOW JUST SOUTH OF CLE. BULK OF STEADY RAIN OVER...BUT SHOWERS AND STORMS WILL PERSIST INTO MONDAY EVENING...AND MOST LIKELY OVERNIGHT MONDAY NIGHT. LEFT SOME IN FAR EASTERN AREAS FOR TUE AM. TOOK MENTION OUT FOR TUE AFT...AS SYSTEM EDGES A LITTLE FURTHER EAST. SHOULD HAVE A DRY DAY ON WED...AS HIGH PRESSURE PREVAILS. SOME CHC OF A SHOWER OR STORM LATER THU INTO FRIDAY...AS A WEAK COLD FRONT MOVES SE. TOOK MENTION OF SHOWERS AND STORMS OUT FOR THE WEEKEND. FIRST WEAK FRONT SHOULD BE SE OF OUR AREA...NEXT COLD FRONT IS STILL NW OF OUR AREA...BASED ON HPC CHARTS. && .AVIATION /20Z SUNDAY THROUGH FRIDAY/... VARIABLE CONDITIONS WILL CONTINUE INTO TONIGHT AS SCT SHRA AND TSTMS AFFECT CENTRAL PA. MANY SOUTHERN LOCATIONS WILL SEE VFR CONDS THIS AFTERNOON AND EVENING...WITH SCT MVFR CIGS AND SHRA/TSRA REDEVELOPING WITH ASSISTANCE FROM THE LOW LEVEL SOLAR HEATING. PRECIP COVERAGE SLOWLY DIMINISHES THIS EVENING AS SHOWERS BECOME MORE HIT AND MISS. BUT WITH UPPER LOW MOVING OVERHEAD...CONDITIONS WILL DETERIORATE WITH MVFR FOG EXPECTED BY 06Z AND THEN SOME IFR CIGS/FOG DEVELOPING AFTER THAT FOR MON MORNING. SHOWERY WEATHER AND VARIABLE CONDITIONS /MAINLY MVFR-IFR/ CONTINUES THROUGH TUE. OUTLOOK... MON-TUE...MVFR-IFR IN AREAS OF SHOWERS. WED-THU...MAINLY VFR. FRI...MVFR WITH SCT SHRA/TSRA. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && SYNOPSIS...DEVOIR/FITZGERALD NEAR TERM...DEVOIR/FITZGERALD SHORT TERM...DEVOIR LONG TERM...GRUMM/MARTIN AVIATION...DEVOIR/RXR
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 959 AM EDT SUN AUG 14 2011 PAZ051>053-057>059-151400- MONTOUR-NORTHUMBERLAND-COLUMBIA-DAUPHIN-SCHUYLKILL-LEBANON- 959 AM EDT SUN AUG 14 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TODAY AND TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS TODAY MAY CREATE LOCALLY HEAVY DOWNPOURS. WIDESPREAD FLOODING IS NOT EXPECTED...BUT MINOR FLOODING IS POSSIBLE IN SPOTS WHERE THUNDERSTORMS LINGER. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. SCATTERED SHOWERS AND THUNDERSTORMS TONIGHT AND MONDAY MAY CREATE LOCALLY HEAVY DOWNPOURS. WIDESPREAD FLOODING IS NOT EXPECTED...BUT MINOR FLOODING IS POSSIBLE IN SPOTS WHERE THUNDERSTORMS LINGER. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PAZ004>006-010>012-017>019-024>028-037-041-042-045-046-049-050-056- 063-151400- WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD- NORTHERN CENTRE-SOUTHERN CENTRE-CAMBRIA-BLAIR-HUNTINGDON-MIFFLIN- JUNIATA-TIOGA-NORTHERN LYCOMING-SULLIVAN-SOUTHERN CLINTON- SOUTHERN LYCOMING-UNION-SNYDER-PERRY-CUMBERLAND- 959 AM EDT SUN AUG 14 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TODAY AND TONIGHT. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PAZ033>036-064-151400- SOMERSET-BEDFORD-FULTON-FRANKLIN-ADAMS- 959 AM EDT SUN AUG 14 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TODAY AND TONIGHT. A STORM SYSTEM APPROACHING FROM OHIO WILL PRODUCE NUMEROUS THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A SLIGHT RISK THAT A FEW OF THESE STORMS COULD PRODUCE DAMAGING WIND GUSTS OR LARGE HAIL. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PAZ065-066-151400- YORK-LANCASTER- 959 AM EDT SUN AUG 14 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TODAY AND TONIGHT. A STORM SYSTEM APPROACHING FROM OHIO WILL PRODUCE NUMEROUS THUNDERSTORMS ACROSS THE AREA TODAY. THERE IS A SLIGHT RISK THAT A FEW OF THESE STORMS COULD PRODUCE DAMAGING WIND GUSTS OR LARGE HAIL. IN ADDITION...LOCALIZED FLOODING IS POSSIBLE FROM HEAVY DOWNPOURS. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. SCATTERED SHOWERS AND THUNDERSTORMS TONIGHT AND MONDAY MAY CREATE LOCALLY HEAVY DOWNPOURS. WIDESPREAD FLOODING IS NOT EXPECTED...BUT MINOR FLOODING IS POSSIBLE IN SPOTS WHERE THUNDERSTORMS LINGER.THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE STATE COLLEGE PA 442 PM EDT SUN AUG 14 2011 PAZ063-142115- CUMBERLAND PA- 442 PM EDT SUN AUG 14 2011 ...A STRONG THUNDERSTORM WILL AFFECT WESTERN CUMBERLAND COUNTY... AT 439 PM EDT...A STRONG THUNDERSTORM WAS NEAR NEWVILLE...MOVING SOUTHEAST AT 10 MPH. WIND GUSTS TO 50 MPH ARE POSSIBLE WITH THIS STORM. VERY HEAVY RAIN WILL FALL FROM THIS STORM...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 STORM WILL AFFECT WALNUT BOTTOM. THIS WILL IMPACT THE FOLLOWING CENTRAL PENNSYLVANIA INTERSTATES...THE PENNSYLVANIA TURNPIKE BETWEEN MILE MARKERS 206 AND 218...I-81 BETWEEN MILE MARKERS 29 AND 44. THIS WILL ALSO IMPACT ROUTE 11. LAT...LON 4016 7715 4001 7741 4014 7758 4026 7744 FORECASTER: DANGELO
The State College radar (KCCX), 38 km away, was scanning. The volume nearest the first event began at 20:48 UTC.
7 thunderstorm wind, 2 hail. Local standard time, as filed.
Thunderstorm winds estimated near 60 mph knocked down trees and utility wires near Clearfield.
Thunderstorm winds estimated near 60 mph knocked down trees and utility wires in Antrim township east of Greencastle.
Thunderstorm winds estimated near 60 mph knocked down several tree limbs in Washington Township. Some debris blocked roads.
Thunderstorm winds estimated near 60 mph knocked down several large tree limbs in Quincy Township north of Waynesboro.
Thunderstorm winds estimated near 60 mph knocked down several large limbs near Waynesboro.
Thunderstorm winds estimated near 60 mph knocked down trees in Wayne Heights just east of Waynesboro.
Thunderstorm winds estimated near 60 mph knocked down trees along Monterey Lane east of Rouzerville.
Pea to nickel size hail (<0.75 to 0.88 inch diameter) reported by NWS Employee in Stormstown.
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, August 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: 322305, 322298, 322299, 322300, 322301, 322303, 322304, 322296, 322297.