A strong cold front triggered severe thunderstorms across north-central Pennsylvania from the mid-afternoon into the evening hours. The severe storms produced several reports of thunderstorm wind damage.
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 strong cold front triggered severe thunderstorms across north-central Pennsylvania from the mid-afternoon into the evening hours. The severe storms produced several reports of thunderstorm wind damage.
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 21, 2:01 PM EST, 24 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 301 PM EDT WED JUL 21 2010 .SYNOPSIS... A FRONT WILL MOVE NORTH OF THE REGION DURING THE DAY BEFORE PUSHING BACK TO THE SOUTH EARLY TONIGHT. THIS SHOULD ALLOW FOR A DRY DAY ON THURSDAY. THAT SAME BOUNDARY WILL RETURN NORTH ON THURSDAY NIGHT...LEADING TO VERY WARM TEMPERATURES FOR FRIDAY AND SATURDAY. A COLD FRONT WILL THEN MOVE THROUGH LATER IN THE WEEKEND. && .NEAR TERM /UNTIL 10 PM THIS EVENING/... THE VERY WARM 8-10C AIR AT 700 HPA APPEARS TO CONTINUE TO KEEP SOUTHERN AREAS CAPPED AND THUS MOSTLY SUNNY AND THUNDER FREE. FARTHER NORTH AND IN THE NORTHWEST...LESS STABLE AIR HAS ALLOWED STORMS TO FORM AND EVOLVE. MOST GET FAIRLY BIG AND A FEW HAVE PERSISTED AND DEVELOPED SOME ROTATION. NO BIG STORMS OR REPORTS OF PROBLEMS. THE NORTHERN TWO THIRDS OF THE AREA ARE UNDER A SEVERE THUNDERSTORM WATCH. SO FAR BEEN SPOTTY BUT IT IS ONLY MID- AFTERNOON. WILL HAVE TO WATCH AND MONITOR STORMS AND SEE HOW IT EVOLVES AS THE FRONT IS STILL TO OUR WEST. CONVECTION SHOULD DIMINISH AND SLIGHTLY DRIER AIR MOVES INTO TONIGHT. TEMPS SHOULD FALL INTO THE MID 60S IN THE NW AND MID 70S IN THE SOUTHEAST BEFORE 10 PM. && .SHORT TERM /10 PM THIS EVENING THROUGH FRIDAY NIGHT/... ANY RESIDUAL CONVECTION SHOULD END BEFORE OR JUST 1-2 HOURS INTO THIS PERIOD. CLEARING SKIES AND COOLER OVERNIGHT. HIGH PRESSURE AT THE SURFACE...A PASSING RIDGE...AND ABOVE NORMAL 850 AND 700 HPA TEMPS FOR THURSDAY SHOULD KEEP THE CONVECTION DOWN. 850 HPA TEMPS CLIMB TO OVER 18C ALONG MD BORDER. HOT AFTERNOON. WARM AIR AT 700 HPA MOVES IN OVER NIGHT THURSDAY INTO FRIDAY. 850 HPA TEMPS PEAK NEAR 20C SOME MODELS SHOW 22C OVER SOUTHERN AND SE AREAS. FRIDAY SHOULD BE A HOT DAY. && .LONG TERM /SATURDAY THROUGH TUESDAY/... GLOBAL MODELS SHOW A SHORTWAVE TROUGH MOVING EWD ACROSS THE NRN ROCKIES INTO THE UPR MS VLY ON DY4...CONTINUING EWD THROUGH THE GREAT LKS AND INTO THE NORTHEAST BY DY6. MEANWHILE THE SUBTROPICAL RIDGE WILL REMAIN ANCHORED OVER THE SOUTHEAST STATES. SLIGHTLY LOWER HEIGHTS ARE PROJECTED IN MEAN OVER THE NORTHEAST BY EARLY NEXT WEEK...WITH PERHAPS MORE PRONOUNCED TROUGHING AND ASSOCIATED COOLER TEMPERATURES TOWARD THE END OF THE MONTH...AS THE SUBTROPICAL RIDGE SLOWLY RETROGRADES WWD INTO THE LWR MS VLY AND SOUTH-CENTRAL PLAINS. NUMEROUS SHOWERS AND THUNDERSTORMS WILL LIKELY ACCOMPANY A COLD FRONT PUSHING SEWD ACROSS THE GRT LKS INTO THE MID-ATLC SAT/SUN. FRIDAY AND SATURDAY STILL LOOK LIKE THE WARMEST DAYS WITH HEAT INDEX/APPARENT TEMPERATURES POSSIBLY EXCEEDING 100F OVER THE LOWER SUSQ VALLEY. HAVE ADDED MENTION TO THE HWO TO ACCOUNT FOR THIS POTENTIAL HEAT-RELATED HAZARD. THE MODELS REMAIN AT ODDS WITH THE EVOLUTION OF THE WEEKEND FRONTAL SYSTEM INTO NEXT WEEK. && .AVIATION /19Z WEDNESDAY THROUGH MONDAY/... SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE TO PUSH EASTWARD ACROSS THE NORTHERN HALF OF THE STATE THIS MORNING. AFTER THE SHOWERS CLEAR THE REGION...THE LOW CLOUD DECKS AND THE MVFR FOG WILL LIFT...ALLOWING FOR CONDITIONS TO BECOME PREDOMINANTLY VFR. AT AROUND 15Z...ANOTHER BATCH OF SHOWERS AND THUNDERSTORMS WILL BEGIN DEVELOP...AS A WARM FRONT REMAINS JUST TO THE NORTH OF THE STATE. THIS PATTERN WILL GIVE THUNDERSTORMS THE POTENTIAL TO BECOME SEVERE AS THEY MOVE EASTWARD ACROSS THE STATE. NONETHELESS...MOST AIRFIELDS SHOULD BE UNDER MAINLY VFR CONDITIONS THROUGHOUT THE DAY...WITH SOME LOCALIZED MVFR AND IFR IN SHRA/TSRA. THE SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CLEAR THE REGION SOON AFTER SUNSET...ALLOWING FOR THE RETURN OF LOW CEILINGS AND MVFR FOG ACROSS PARTS OF THE REGION AFTER 06Z. OUTLOOK... THU...MAINLY VFR. THU NIGHT-SUN...MAINLY VFR...WITH MVFR POSS IN SCTD SHRA/TSRA. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && SYNOPSIS...DANGELO NEAR TERM...GRUMM SHORT TERM...GRUMM LONG TERM...STEINBUGL AVIATION...MARTIN/KOZAR
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 135 PM EDT WED JUL 21 2010 PAZ024>028-033>036-056-063>065-221745- CAMBRIA-BLAIR-HUNTINGDON-MIFFLIN-JUNIATA-SOMERSET-BEDFORD-FULTON- FRANKLIN-PERRY-CUMBERLAND-ADAMS-YORK- 135 PM EDT WED JUL 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON. THE PREDOMINATE HAZARD WILL BE DAMAGING WINDS...WITH LARGE HAIL AND OR EVEN AN ISOLATED BRIEF TORNADO A SECONDARY THREAT. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ON FRIDAY. APPARENT TEMPERATURES IN EXCESS OF 95 TO 100 DEGREES ARE POSSIBLE ON FRIDAY AND SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND EVENING. PAZ004>006-010>012-037-041-042-221745- WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-TIOGA- NORTHERN LYCOMING-SULLIVAN- 135 PM EDT WED JUL 21 2010 ...SEVERE THUNDERSTORM WATCH 507 IN EFFECT UNTIL 8 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. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ON FRIDAY AND SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL LIKELY BE NEEDED THIS AFTERNOON AND EVENING. PAZ017>019-045-046-049>053-057>059-066-221745- CLEARFIELD-NORTHERN CENTRE-SOUTHERN CENTRE-SOUTHERN CLINTON- SOUTHERN LYCOMING-UNION-SNYDER-MONTOUR-NORTHUMBERLAND-COLUMBIA- DAUPHIN-SCHUYLKILL-LEBANON-LANCASTER- 135 PM EDT WED JUL 21 2010 ...SEVERE THUNDERSTORM WATCH 507 IN EFFECT UNTIL 8 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. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ON FRIDAY. APPARENT TEMPERATURES IN EXCESS OF 95 TO 100 DEGREES ARE POSSIBLE ON FRIDAY AND SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL LIKELY BE NEEDED THIS AFTERNOON AND EVENING. MS
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE STATE COLLEGE PA 151 PM EDT WED JUL 21 2010 PAZ004-211830- WARREN PA- 151 PM EDT WED JUL 21 2010 ...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN WARREN COUNTY... AT 150 PM EDT...A STRONG THUNDERSTORM WAS 20 MILES NORTH OF OIL CITY...MOVING EAST AT 30 MPH. WIND GUSTS TO 30 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS STORM. THIS STORM WILL BE NEAR GRAND VALLEY AROUND 200 PM...GARLAND AROUND 210 PM...TIDIOUTE AROUND 215 PM AND CHAPMAN STATE PARK AROUND 230 PM. THIS WILL IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 6...ROUTE 62... STATE ROAD 59. LAT...LON 4188 7908 4164 7905 4163 7962 4182 7963 FORECASTER: RHG
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
156 PM EDT WED JUL 21 2010
PAZ012-045-211830-
NORTHERN CLINTON PA-SOUTHERN CLINTON PA-
156 PM EDT WED JUL 21 2010
...A STRONG THUNDERSTORM WILL AFFECT CENTRAL CLINTON COUNTY...
AT 155 PM EDT...A STRONG THUNDERSTORM WAS NEAR KEATING...MOVING
SOUTHEAST AT 30 MPH.
WIND GUSTS TO 40 MPH AND SMALL HAIL ARE POSSIBLE WITH THIS STORM.
DOPPLER RADAR HAS INDICATED SOME ROTATION WITH THIS STORM. THIS
STORM WILL BE NEAR HYNER AROUND 215 PM AND GLEN UNION AROUND 225 PM.
THIS WILL IMPACT STATE ROAD 120.
LAT...LON 4126 7741 4105 7753 4124 7791 4126 7791
4125 7793 4129 7801 4136 7793
FORECASTER: STEINBUGLSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE STATE COLLEGE PA 157 PM EDT WED JUL 21 2010 PAZ005-006-211830- MCKEAN PA-POTTER PA- 157 PM EDT WED JUL 21 2010 ...A STRONG THUNDERSTORM WILL AFFECT NORTHERN MCKEAN AND NORTHWESTERN POTTER COUNTIES... AT 155 PM EDT...A STRONG THUNDERSTORM WAS NEAR BRADFORD...MOVING EAST AT 35 MPH. WIND GUSTS TO 30 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS STORM. THIS STORM WILL BE NEAR CYCLONE AROUND 205 PM...REW AROUND 210 PM... SMETHPORT AROUND 215 PM...CORYVILLE AROUND 220 PM...PORT ALLEGANY AROUND 225 PM AND SHINGLEHOUSE AROUND 230 PM. THIS WILL IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 6...ROUTE 219... STATE ROAD 46...STATE ROAD 59...STATE ROAD 446. LAT...LON 4197 7793 4173 7796 4182 7886 4200 7883 FORECASTER: RHG
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
232 PM EDT WED JUL 21 2010
PAZ005-010-211900-
ELK PA-MCKEAN PA-
232 PM EDT WED JUL 21 2010
...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN ELK AND SOUTHERN
MCKEAN COUNTIES...
AT 227 PM EDT...A STRONG THUNDERSTORM WAS NEAR KANE...MOVING EAST AT
30 MPH.
WIND GUSTS TO 30 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS STORM.
THIS STORM WILL BE NEAR WILCOX AROUND 245 PM...MOUNT JEWETT AROUND
250 PM AND KINZUA BRIDGE STATE PARK AROUND 255 PM.
THIS WILL IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 6...ROUTE 219...
STATE ROAD 66.
LAT...LON 4177 7839 4162 7837 4162 7842 4154 7843
4154 7895 4172 7896
FORECASTER: RHGSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE STATE COLLEGE PA 239 PM EDT WED JUL 21 2010 PAZ005-006-037-211915- MCKEAN PA-POTTER PA-TIOGA PA- 239 PM EDT WED JUL 21 2010 ...A STRONG THUNDERSTORM WILL AFFECT CENTRAL POTTER...EAST CENTRAL MCKEAN AND WEST CENTRAL TIOGA COUNTIES... AT 236 PM EDT...A STRONG THUNDERSTORM WAS 20 MILES SOUTHEAST OF BRADFORD...MOVING EAST AT 35 MPH. WIND GUSTS TO 30 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS STORM. THIS STORM WILL BE NEAR ROULETTE AROUND 245 PM...COUDERSPORT AROUND 255 PM...LYMAN RUN STATE PARK AROUND 305 PM AND GALETON AROUND 315 PM. THIS WILL IMPACT ROUTE 6. LAT...LON 4180 7755 4158 7761 4171 7840 4189 7836 FORECASTER: RHG
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
252 PM EDT WED JUL 21 2010
PAZ004>006-010>012-211915-
CAMERON PA-ELK PA-MCKEAN PA-NORTHERN CLINTON PA-POTTER PA-WARREN PA-
252 PM EDT WED JUL 21 2010
...A STRONG THUNDERSTORM WILL AFFECT CAMERON...NORTHERN ELK...
NORTHWESTERN CLINTON...SOUTHEASTERN WARREN...SOUTHWESTERN MCKEAN AND
SOUTHWESTERN POTTER COUNTIES...
AT 250 PM EDT...A STRONG THUNDERSTORM WAS 14 MILES SOUTHWEST OF
KANE...MOVING EAST AT 40 MPH.
WIND GUSTS TO 30 MPH AND PEA SIZE HAIL ARE POSSIBLE WITH THIS STORM.
THIS STORM WILL BE NEAR JAMES CITY AROUND 305 PM...WILCOX AROUND 310
PM AND JOHNSONBURG AROUND 315 PM.
THIS WILL IMPACT THE FOLLOWING MAJOR ROADS...ROUTE 219...STATE ROAD
66...STATE ROAD 120...STATE ROAD 255.
LAT...LON 4158 7791 4126 7802 4145 7897 4162 7896
4162 7898 4163 7913 4167 7912
FORECASTER: RHGThe State College radar (KCCX), 66 km away, was scanning. The volume nearest the first event began at 19:27 UTC.
10 thunderstorm wind, 1 funnel cloud. Local standard time, as filed.
Thunderstorm winds estimated near 60 mph knocked down trees in Truman.
Thunderstorm winds estimated near 60 mph knocked down trees near Ridgway.
Thunderstorm winds estimated near 60 mph knocked down trees in Emporium.
Thunderstorm winds estimated near 60 mph knocked down trees along Ridge Road and Gratzmar Avenue in Renovo.
Thunderstorm winds estimated near 60 mph knocked down trees along Gillingham Road in Girard Township.
The Clearfield County 911 Center reported a funnel cloud sighted between Winburne and Lanse.
NWS meteorologists surveyed significant thunderstorm wind damage in the Centre Hall area. Thunderstorm winds estimated between 60 and 70 mph knocked down numerous trees and wires near the junction of Route 144 and Sinking Creek Road. Several utility poles were knocked down along Route 45 west of Old Fort. Sporadic tree damage was found in an area approximately two miles wide by four miles long, starting a few miles southwest of Centre Hall on Brush Valley Road. Minor roof damage to two structures was also observed. The downed utility poles and wires closed State Route 45 in both directions between Route 144 near Centre Hall and U.S. 322 at Oak Hall. The downed wires also resulted in over 500 power outages.
Thunderstorm winds estimated near 60 mph knocked down trees and wires in Juniata and Oliver Townships near Newport.
Thunderstorm winds estimated near 60 mph knocked down trees near New Ringgold.
Thunderstorm winds estimated near 60 mph knocked down trees along Summer Valley Road (State Route 865).
Thunderstorm winds estimated near 60 mph knocked down trees in Schuylkill Haven.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2010Every state in 2010This day in weather historyWarnings in Pennsylvania, July 2010
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: 238006, 238007, 238008, 238017, 238018, 237997, 238015, 238016, 237998, 238002, 238004.