Severe thunderstorm clusters across western Pennsylvania organized into bowing line segments as they moved east-southeast across the southern Alleghenies and Laurel Highlands during the late afternoon and early evening. The line of storms produced isolated wind damage and sub-severe hail.
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.
Severe thunderstorm clusters across western Pennsylvania organized into bowing line segments as they moved east-southeast across the southern Alleghenies and Laurel Highlands during the late afternoon and early evening. The line of storms produced isolated wind damage and sub-severe hail. A more discrete thunderstorm cell just ahead of the main line of storms produced a brief, weak EF0 tornado in Somerset County. An area of locally heavy rain produced flash flooding in York County during the late evening, with areal flooding persisting into the early morning on 8/8.
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 7, 2:26 PM EST, 1 hour 39 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 326 PM EDT WED AUG 7 2013 .SYNOPSIS... AN ACTIVE AND UNSETTLED WEATHER PATTERN WILL DEVELOP ACROSS CENTRAL PENNSYLVANIA INTO THE WEEKEND...AS A FRONTAL SYSTEM FROM THE MIDWEST SLOWLY CROSSES THE REGION AND THEN STALLS NEAR THE MASON- DIXON LINE. A GRADUAL WARMING TREND TO NEAR NORMAL TEMPERATURES IS EXPECTED THROUGH THE END OF THE WEEK. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... CLOUDS HAVING TROUBLE BREAKING UP ACROSS MOST OF CWA THIS AFTERNOON WITH A MORE WINTER LIKE COLD AIR DAMMING PATTERN WITH LOW LEVEL NE AG FLOW WITH FRONTAL BOUNDARY SOUTH OF CWA. HAVE SEEN A FEW LIGHT SHOWERS DEVELOP AND DISSIPATE ACROSS AREA BUT MORE ACTIVE CONVECTION MOVING INTO AREA FROM THE W. ANTICIPATING THESE STORMS WILL WEAKEN AS THE MOVE EASTWARD INTO A MORE STABLE AIR MASS...THOUGH A FEW LOCALLY HEAVY SHORT LIVED DOWNPOURS AND LIGHTNING STRIKES ARE POSSIBLE THROUGH THE EVENING HOURS. TEMPERATURES WILL FALL LITTLE OVERNIGHT MAINLY STAYING IN THE 60S WITH DEWPOINTS NOTICEABLY HIGHER THEN WE'VE SEEN OVER THE LAST COUPLE WEEKS. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... MODELS SHOW A PW SURGE ALONG FRONTAL BOUNDARY APPROACHES THE REGION ON THU AND WILL KEEP THE POPS HIGH FOR SHOWERS AND THUNDERSTORMS ESPECIALLY IN THE AFTERNOON. STILL VARIABILITY IN THE SOLUTIONS AS TO THE LOCATION AND AMOUNTS OF RAINFALL ACROSS THE AREA...BUT SOME LOCALLY HEAVY DOWNPOURS ARE POSSIBLE. HIGH TEMPERATURES WILL BE WARMER WITH MORE SUN EXPECTED. DEWPOINTS WILL BE OPPRESSIVE...LIKELY TOPPING 70 IN MANY SPOTS. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... PERSISTENT SOUTHWEST TO WEST-SOUTHWESTERLY FLOW ALOFT LOOKS TO PERSIST THROUGH THE LONG TERM PERIOD ON THE SOUTHERN EDGE OF AN UPPER LOW OVER HUDSON BAY. SEVERAL PRONOUNCED SHORTWAVES ROTATING AROUND THE UPPER LOW WILL SUPPORT SEVERAL FRONTS MOVING FROM THE GREAT LAKES EAST INTO THE NORTHEAST. AIR FLOW AHEAD OF THE FRONT WILL KEEP THE REGION IN A MOIST AIR FLOW AT LEAST INTO THE WEEKEND...OR UNTIL THE MAIN FRONTAL BOUNDARY PUSHES THROUGH. ATTEMPTS IN RECENT DAYS FOR THE FRONTS/MOISTURE TO BE PUSHED EASTWARD BY OR THROUGH THE WEEKEND CONTINUE TO BE SLOWED BY THE LATEST MODEL RUNS. HAVE THUS LEANED PESSIMISTIC AND KEPT GENERALLY LOW CHANCE OF SHOWERS ACROSS SRN SECTION NOT ONLY THROUGH THE WEEKEND BUT INTO NEXT WEEK AS A FRONT A BOUNDARY LOOKS TO LAY TO THE SOUTH OF PA WITH THE POTENTIAL FOR WAVES OF LOW PRESSURE TO RUN ALONG IT. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... SOUTHEAST FLOW WILL KEEP LOW STRATUS DECK ACROSS THE REGION WITH IFR TO LOW MVFR CIGS PERSISTING THIS AFTERNOON. ADDED A TEMPO TO DEAL WITH BAND OF CONVECTION THAT WILL MOVE ACROSS THE REGION THIS AFTERNOON AND EVENING. SEVERAL ROUNDS OF SHOWERS AND TSTMS EXPECTED THU-FRI AS FRONTAL WAVES MOVE ACROSS REGION. OUTLOOK... THU-FRI...GENERALLY MVFR WITH PERIODS OF SHOWERS/TSTMS. SAT-SUN...RETURN TO MAINLY VFR AS FRONT IS FCST TO BRIEFLY PUSH SWD...HOWEVER THE LATEST MDL RUNS SUGGEST ANOTHER FRONTAL WAVE MAY IMPACT SRN PA LATER SUNDAY. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && SYNOPSIS...ROSS/STEINBUGL NEAR TERM...ROSS SHORT TERM...ROSS LONG TERM...GARTNER AVIATION...ROSS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 359 PM EDT WED AUG 7 2013 PAZ017-024-033-082000- CLEARFIELD-CAMBRIA-SOMERSET- 359 PM EDT WED AUG 7 2013 ...SEVERE THUNDERSTORM WATCH 482 IN EFFECT UNTIL 10 PM EDT THIS EVENING... THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND 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...THURSDAY THROUGH TUESDAY. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. PAZ010-011-018-025-034-082000- ELK-CAMERON-NORTHERN CENTRE-BLAIR-BEDFORD- 359 PM EDT WED AUG 7 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. THUNDERSTORMS WITH GUSTY WINDS ARE POSSIBLE LATE THIS AFTERNOON THROUGH EARLY THIS EVENING. ISOLATED STORMS MAY CONTAIN STRONG GUSTY WINDS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PAZ004>006-012-019-026>028-035>037-041-042-045-046-049>053-056>059- 063>066-082000- WARREN-MCKEAN-POTTER-NORTHERN CLINTON-SOUTHERN CENTRE-HUNTINGDON- MIFFLIN-JUNIATA-FULTON-FRANKLIN-TIOGA-NORTHERN LYCOMING-SULLIVAN- SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER-MONTOUR- NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-CUMBERLAND- ADAMS-YORK-LANCASTER- 359 PM EDT WED AUG 7 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. RXR
The State College radar (KCCX), 66 km away, was scanning. The volume nearest the first event began at 21:04 UTC.
10 thunderstorm wind, 3 hail, 2 funnel cloud, 1 tornado, 1 flash flood. Local standard time, as filed.
Thunderstorm winds estimated near 60 mph knocked down trees and utility wires near DuBois.
Thunderstorm winds estimated near 60 mph knocked down several large trees in Treasure Lake.
Thunderstorm winds estimated near 60 mph knocked down trees along Route 255 southwest of Penfield.
Thunderstorm winds estimated near 60 mph knocked down a large tree along Bennetts Valley Highway (Route 255) near Weedville.
Thunderstorm winds estimated near 60 mph knocked down trees and utility wires in Jackson Township.
Quarter inch hail (1 inch diameter) was reported near Amberson Valley.
A funnel cloud was sighted looking south from Mile Hill Road.
Thunderstorm winds estimated near 60 mph knocked down a few large trees and blew a dilapidated roof off of a barn near Jennerstown along Route 30.
Thunderstorm straight-line winds estimated near 80 mph knocked down the front and back walls and took the roof of a metal barn (the side walls remained standing). A steel wagon in the barn was turned on its side. Pieces of the roof were located several hundred yards to the east in a field along with several downed trees. The damage occurred in Lincoln Township along Keysertown and Bell Lane Road.
Nickel size hail (0.88 inch diameter) was reported in Windber.
Quarter size hail (1 inch diameter) was reported near Amberson Valley.
A funnel cloud was sighted a few miles southeast of Windber.
A storm survey conducted in Quemahoning Township in Somerset County confirmed a brief, weak EF0 tornado occurred a few miles east of Ralphton near Horner Church Road. One home sustained minor damage and one barn roof was partially torn off. Over 2 dozen trees were knocked down or damaged. The estimated maximum wind speed was between 70-80 mph. The maximum path width was 75 yards with a path length of about 0.25 mile. There were no injuries or fatalities.
Thunderstorm winds estimated near 60 mph knocked down a large tree in Windber.
Thunderstorm winds estimated near 60 mph knocked down trees along North Road.
Thunderstorm winds estimated near 60 mph knocked down several trees near Port Royal.
Heavy thunderstorm rains produced flash flooding across portions of southern York County during the late evening and early overnight hours. Spotter reports indicated two inches of rain fell in about 1 hour. Street flooding was reported in Hanover. A water rescue was conducted at the intersection of Seven Valleys Road (State Route 616) and Maple Street in North Codorus Township. A motorist drove her car into Codorus Creek which has flooded over the road. Emergency responders were able to rescue both occupants of the stranded vehicle. This section of the road along Codorus Creek was closed for much of the night.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2013Every state in 2013This day in weather historyThe tornado archive for Pennsylvania, 2013Warnings in Pennsylvania, August 2013
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: 459099, 459097, 459098, 459100, 459101, 459093, 459855, 459102, 459690, 459094, 459095, 459857, 459096, 459108, 459109, 459107, 459117.