A bands of thunderstorms associated with a weakening squall line moved southeast from Lake Erie during the pre-dawn hours and produced isolated wind damage in the western Alleghenies. A tree toppled by the severe winds fell on a house in Somerset, killing a 10-year old female.
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 bands of thunderstorms associated with a weakening squall line moved southeast from Lake Erie during the pre-dawn hours and produced isolated wind damage in the western Alleghenies. A tree toppled by the severe winds fell on a house in Somerset, killing a 10-year old female.
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 24, 11:56 PM EST, 54 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1256 AM EDT THU AUG 25 2011 .SYNOPSIS... STRONG UPPER LEVEL TROUGH AND ASSOCIATED COLD FRONT WILL TRACK EAST FROM THE GREAT LAKES AND OHIO VALLEY INTO THE NORTHEAST AND MID ATLANTIC REGION OVER THE NEXT 36 HOURS. THE COLD FRONT WILL PUSH THROUGH THE KEYSTONE STATE TODAY BRINGING SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL RETURN TO THE AREA ON FRIDAY AND BRING FAIR AND DRY WEATHER. HURRICANE IRENE IS FORECAST TO MOVE NORTH NEAR OR JUST OFFSHORE THE EASTERN SEABOARD...AND COULD IMPACT EASTERN PENNSYLVANIA WITH HEAVY RAIN THIS WEEKEND. FAIR WEATHER WILL RETURN FOR EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... UPDATE FOR SEVERE THUNDERSTORM WATCH 806 IN EFFECT UNTIL 6AM FOR THE N/W MTNS. IMPRESSIVE LINE OF TSTMS WORKING SEWD FROM LAKE ERIE EARLY THIS MORNING ALONG AXIS OF MOD INSTABILITY AND STRONG WSWLY LLJ. VERY STRONG FLOW IN THE LOW LEVELS WILL SUPPORT ISOLATED DAMAGING WIND THREAT IN THE MORE INTENSE BOWING LINE SEGMENTS. THE SEVERE THREAT SHOULD DECREASE FURTHER S/E INTO THE ALLEGHENY FOOTHILLS GIVEN WEAKER INSTABILITY. COSPA/HI RES MDL DATA SUPPORTS THIS FCST TREND AS PCPN ENTERS THE CNTRL MTNS AROUND 09-10Z. PREVIOUS DISCUSSION BELOW. ANOTHER QUIET EVENING FOR NOW ACROSS CENTRAL PA...BUT NOT TOO FAR UPSTREAM IT HAS BECOME ACTIVE AS A TROUGH PUSHING INTO THE EASTERN GLAKS IS IGNITING A LINE OF SCATTERED STORMS FROM SOUTHERN LOWER MICHIGAN NORTHEASTWARD INTO SOUTHERN ONTARIO. TIMING OF DETERMINISTIC MESO MODELS BRINGS THIS INTO MY NORTHWEST COUNTIES BY OR SHORTLY AFTER MIDNIGHT. TSTMS WILL BECOME MORE NUMEROUS AND LIKELY ORGANIZE INTO A LINE AFTER 06Z IN THE NW...WITH POSS OF ISOLD STRONGER WIND GUSTS AS LOW LEVEL JET INCREASES. ALONG A KAOO-KIPT LINE PRECIP CHANCES DON/T SIGNIFICANTLY INCREASE UNTIL AFTER 06Z AS THE BROKEN LINE OF STORMS TRACK EASTWARD...THOUGH THESE SHOULD BE SLOWLY DIMINISHING AS THEY ENTER THE CENTRAL MTNS. THE LOWER SUSQ WILL NOT SEE CONVECTION UNTIL AFTER 12Z. AFTER BREEZY WINDS DIMINISH THIS EVENING...A MILDER NIGHT THAN LAST NIGHT WILL BE IN STORE. TEMPS WILL REMAIN IN THE LOWER/MID 60S IN MOST LOCATIONS. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/... A STRONG UPPER TROUGH AXIS WILL SWEEP EWD ACROSS THE UPPER OH VALLEY/ERN GRT LKS TO A NY TO VA LINE BY 00Z FRI...GRADUALLY WEAKENING AS LEADING JET MAX/DYNAMICS ALOFT EJECT NEWD INTO SERN CANADA. AT THE SURFACE...SWLY FLOW WILL MAINTAIN MOISTURE FLUX/RIBBON OF 1.5-2.0 INCH PWATS AHEAD OF A COLD FRONT WHERE MARGINAL INSTABILITY WILL MATERIALIZE DURING THE DAY. MODELS ARE IN RELATIVELY GOOD AGREEMENT OVERALL WITH THIS SYSTEM...AND SPC NOW HAS AN AREA OF SLIGHT RISK SVR TSTMS FROM NEAR THE EASTERN EDGE OF OUR CWA...EASTWARD. A FAVORABLY MOIST AND INCREASINGLY UNSTABLE AIR MASS PRECEDING FRONTAL LIFT/WAA SHOULD RESULT IN SCT TO NMRS TSTMS. THE THREAT OF SEVERE STORMS STILL LOOKS MARGINAL GIVEN MODEST SHEAR AND POOR MID LEVEL LAPSE RATES. THE GREATEST RISK FOR SEVERE WEATHER IS ACRS THE LWR SUSQ VLY GIVEN JUXTAPOSITION OF BEST INSTABILITY/HEATING AND LLVL MSTR /SFC DEWPTS 65-70F/. STORMS WILL ALSO BE CAPABLE OF PRODUCING LOCALLY HEAVY RNFL GIVEN HI PWATS AND 30-40KT LLJ...BUT THIS MAY COUNTERED TO SOME DEGREE BY PROGRESSIVE NATURE OF THE FROPA. THE EXCEPTION MAY BE OVR SERN PA AS THE GUIDANCE SHOWS A LOCAL RNFL MAX DEVELOPING UNDER THE RIGHT ENTRANCE REGION OF THE UPPER JET. THEREFORE WILL NEED TO WATCH OUT FOR FLOOD/FF THREAT GIVEN WET ANTECEDENT CONDS AND LOWER FFG VALUES. USED A GENERAL COMPROMISE FOR QPF GIVEN GOOD MODEL AGREEMENT WITH A TILT TOWARD THE 00Z ECMWF. STARTING THU NIGHT...EXPECT FAIR AND DRY WEATHER TO PREVAIL ACRS THE KEYSTONE STATE WITH SFC RIDGE AXIS ANCHORED ALONG THE ERN LKS. FOCUS WILL THEN SHIFT TO HURRICANE IRENE OVER THE WEEKEND. ANYWAY...WILL MONITOR THE SITUATION...AS THE AIRMASS JUST TO THE WEST IS QUITE HOT AHD HUMID THIS AFT...AND WITH MODERATE DYNAMICS MOVING ON THU...CONCERN IS THAT SYSTEM MAY BE STRONGER THAN THE CURRENT MODELS HAVE. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... TENDENCY OF THE MODELS IS A LITTLE FURTHER EAST WITH THE HURRICANE. HOWEVER...STILL CLOSE ENOUGH TO BRING SOME SHOWERS AND STORMS TO THE AREA LATER SATURDAY INTO SUNDAY. SYSTEM IS MOVING FAST ENOUGH NOW...THAT LITTLE POTENTIAL FOR RAIN WILL BE LEFT AFTER SUNDAY EVENING. MAIN CHANGE WAS TO EDGE HIGHER POPS JUST A LITTLE TO THE WEST. MAIN CONCERN REMAINS THAT IS SOME HINT IN THE MODEL DATA OF A PRE RNFL EVENT PERHAPS REACHING AS FAR NORTH/WEST AS SE PA BY SAT MORNING...WITH THE GREATEST THREAT OF TROPICAL RNFL SEEMINGLY FROM SAT NGT INTO EARLY SUNDAY. OVERALL THE LATEST TREND IS FOR A MORE EASTERLY...MAINLY OFFSHORE TRACK BEFORE MDL DIFFS ARISE ON POTENTIAL LANDFALL SUNDAY. THERE WILL BE A VERY TIGHT RNFL GRADIENT ON THE WRN SIDE OF THE TROPICAL SYSTEM. WHILE THERE IS STILL PLENTY OF UNCERTAINTY IN THE TRACK OF HURRICANE IRENE AT THESE RANGES...IT LOOKS LIKE PORTIONS OF CENTRAL AND ESPECIALLY WRN PA COULD MAKE IT THROUGH THIS SYSTEM LARGELY UNSCATHED. IRENE IS EVENTUALLY ABSORBED INTO A LG SCALE TROUGH PROGRESSING EWD THROUGH SERN CANADA EARLY NEXT WEEK. SUBSIDENCE AND REBOUNDING HEIGHTS ALOFT IN THE WAKE OF IRENE SHOULD AFFORD A SEASONABLY WARM AND MAINLY DRY START NEXT WEEK. EXPECT MOST OF MONDAY INTO WED TO BE DRY...WITH TEMPS TYPICAL OF LATE AUG. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... HIGH DEWPOINTS ARE SURGING INTO WESTERN PA...HELPING TO SUPPORT THE DEVELOPMENT OF SOME MVFR CIGS OVER THE HIGH TERRAIN TERMINALS LIKE JST-BFD. RADAR SHOWS A LINE OF INTENSE CONVECTION JUST MOVING OVER LAKE ERIE AT THIS HOUR. HIGH RES ARW IS SEEING THIS FEATURE REMARKABLY WELL BUT MAY BE AN HOUR OR TWO FAST...WITH TIMING SUGGESTING IT WILL ENTER THE NWRN MOUNTAINS AROUND 06Z. FROM THERE THE EVOLUTION OF THE LINE COMES INTO QUESTION. THE HRRR WEAKENS IT SIGNIFICANTLY. THE ARW AND THE NAM-PARA SUGGEST CONVECTION BECOMES LESS FOCUSED BUT MORE WIDESPREAD LATER TONIGHT. EITHER WAY CONDITIONS WILL REMAIN PRIMARILY VFR EXCEPT IN AND NEAR CONVECTIVE LINE OVERNIGHT...THOUGH LIGHT FOG AND THE MARGINAL CEILINGS OVER WESTERN HIGH TERRAIN WILL CAUSE SOME RESTRICTIONS FOR A TIME OVERNIGHT. IF WIDESPREAD SHOWERS AND STORMS FORM AS SOME GUIDANCE SUGGESTS...EXPECT MORE EXTENSIVE REDUCED CONDITIONS TO FORM ASSOCIATED WITH THE RAIN. WIDESPREAD CONVECTION WILL CONTINUE TO BRING REDUCTIONS ON THURSDAY UNTIL PRECIP ENDS FROM NW TO SE. OUTLOOK... FRI/SAT...NO SIG WX EXPECTED. SAT NIGHT-SUN...HEAVY RAIN AND STRONG FLIGHT-LEVEL WINDS POSSIBLE EASTERN SECTIONS DUE TO HURRICANE IRENE. MON...PRIMARILY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && SYNOPSIS...MARTIN/RXR/STEINBUGL NEAR TERM...STEINBUGL SHORT TERM...MARTIN/STEINBUGL LONG TERM...MARTIN/STEINBUGL AVIATION...LA CORTE
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 1248 AM EDT THU AUG 25 2011 PAZ012-018-019-025>028-033>036-041-042-045-046-049>053-056>059- 063>066-260500- NORTHERN CLINTON-NORTHERN CENTRE-SOUTHERN CENTRE-BLAIR-HUNTINGDON- MIFFLIN-JUNIATA-SOMERSET-BEDFORD-FULTON-FRANKLIN-NORTHERN LYCOMING- SULLIVAN-SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER-MONTOUR- NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-CUMBERLAND- ADAMS-YORK-LANCASTER- 1248 AM EDT THU AUG 25 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT. THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. A COLD FRONT WILL MOVE ACROSS PENNSYLVANIA TODAY AND MAY PRODUCE STRONG TO LOCALLY SEVERE THUNDERSTORMS. THE GREATEST RISK FOR SEVERE WEATHER IS OVER EASTERN AREAS. IN ADDITION...HEAVY CONVECTIVE RAINFALL IS POSSIBLE WHICH COULD LEAD TO FLOODING. HURRICANE IRENE IS FORECAST TO TRACK ALONG OR JUST EAST OF THE MID ATLANTIC COAST THIS WEEKEND. THIS TROPICAL SYSTEM MAY BRING HEAVY RAIN AND GUSTY WINDS TO EASTERN PENNSYLVANIA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. PAZ004>006-010-011-017-024-037-260500- WARREN-MCKEAN-POTTER-ELK-CAMERON-CLEARFIELD-CAMBRIA-TIOGA- 1248 AM EDT THU AUG 25 2011 ...SEVERE THUNDERSTORM WATCH 806 IN EFFECT UNTIL 6 AM EDT EARLY THIS MORNING... 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...THURSDAY THROUGH TUESDAY. A COLD FRONT WILL MOVE ACROSS PENNSYLVANIA TODAY AND MAY PRODUCE STRONG TO LOCALLY SEVERE THUNDERSTORMS. THE GREATEST RISK FOR SEVERE WEATHER IS OVER EASTERN AREAS. IN ADDITION...HEAVY CONVECTIVE RAINFALL IS POSSIBLE WHICH COULD LEAD TO FLOODING. HURRICANE IRENE IS FORECAST TO TRACK ALONG OR JUST EAST OF THE MID ATLANTIC COAST THIS WEEKEND. THIS TROPICAL SYSTEM MAY BRING HEAVY RAIN AND GUSTY WINDS TO EASTERN PENNSYLVANIA. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT SEVERE WEATHER TO THE NATIONAL WEATHER SERVICE IN STATE COLLEGE.
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1241 AM EDT THU AUG 25 2011
PAZ004-250515-
WARREN PA-
1241 AM EDT THU AUG 25 2011
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHERN WARREN
COUNTY...
AT 1242 AM EDT...A LINE OF STRONG THUNDERSTORMS WAS LOCATED FROM 7
MILES NORTH OF FREWSBURG TO 13 MILES WEST OF ELGIN...MOVING EAST AT
60 MPH.
WIND GUSTS TO 50 MPH AND SMALL HAIL ARE POSSIBLE WITH THESE STORMS.
THESE STORMS WILL AFFECT COLUMBUS...SUGAR GROVE...RUSSELL AND
YOUNGSVILLE.
LAT...LON 4200 7892 4193 7892 4169 7961 4170 7962
4200 7961
FORECASTER:The Buffalo radar (KBUF), 128 km away, was scanning. The volume nearest the first event began at 05:50 UTC.
2 thunderstorm wind. Local standard time, as filed.
Thunderstorm winds estimated near 60 mph knocked down a large limb and utility wires in Warren city.
Thunderstorm winds estimated near 60 mph knocked down a tree which fell onto a residential home on Stepping Stone Road on the south-side of Somerset, causing significant damage. A 10-year old female in the house was killed by the falling tree.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Thunderstorm Wind, Somerset | 2011-08-25 | 10 | Female | Permanent Home | Direct |
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: 326906, 326908.