A broken line of severe thunderstorms formed ahead of a cold front during the late afternoon, and produced localized wind damage and heavy rainfall across portions of east-central Pennsylvania. The heavy rain combined with above normal soil moisture and high stream-flows contributed to flash flooding.
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 broken line of severe thunderstorms formed ahead of a cold front during the late afternoon, and produced localized wind damage and heavy rainfall across portions of east-central Pennsylvania. The heavy rain combined with above normal soil moisture and high stream-flows contributed to flash flooding.
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 May 3, 3:01 PM EST, 59 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 401 PM EDT TUE MAY 3 2011 .SYNOPSIS... A PLUME OF DEEP...TROPICAL MOISTURE EXTENDED FROM THE WESTERN GULF OF MEXICO...TO THE OHIO VALLEY AND LOWER GREAT LAKES. THIS MOISTURE WILL INTERACT WITH A STATIONARY FRONTAL BOUNDARY OVER PENNSYLVANIA TO BRING A SOAKING RAIN TO MUCH OF THE AREA THIS AFTERNOON AND TONIGHT. A WARMER AND MORE UNSTABLE AIRMASS ACROSS THE SOUTHEASTERN HALF OF THE STATE WILL LEAD TO THE DEVELOPMENT OF SCATTERED STRONG...TO POTENTIALLY SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING. THE FRONT WILL PUSH EAST OF THE REGION EARLY WEDNESDAY MORNING. UNSEASONABLY COLD AIR WILL OCCUR WEDNESDAY INTO EARLY THURSDAY WITH NUMEROUS SHOWERS ACROSS THE NORTHERN AND WESTERN MOUNTAINS...AND SCATTERED SHOWERS ELSEWHERE. A BRIEF PERIOD OF FAIR..DRY WEATHER WILL OCCUR ON THURSDAY. UNSETTLED WEATHER WILL FOLLOW FOR FRIDAY THROUGH THE UPCOMING THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... ALSO SENT WCN...SEVERE WATCH FOR MUCH OF THE AREA UNTIL 10 PM. EXPANDED FLASH FLOOD WATCH. BUILDING 925-850 MB THETA-E RIDGE INTO THE S CENTRAL MTNS IS CAUSING SIGNIFICANT BACKBUILDING OF CELLS OVER THE AREA. RADAR ESTIMATES OF 0.75" ALREADY BEING SEEN IN BEDFORD COUNTY. STRONG SHEAR AND FAVORABLE STORM PROPAGATION WILL CAUSE BACKBUILDING AND LANDLOCKED CELLS TO CONTINUE TO PRODUCE HEAVY RAIN OVER THE SAME AREAS THIS AFTERNOON INTO THIS EVENING AND HAVE EXPANDED THE EXISTING FLASH FLOOD WATCH SOUTHWARD AND WESTWARD TO INCLUDE MUCH OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. WATCHING SVR STORM POTENTIAL FROM THE MID SUSQUEHANNA RIVER VALLEY THROUGH THE SOUTH CENTRAL MOUNTAINS LATE THIS AFTERNOON AND EVENING...ALONG WITH ISOLATED TOR POTENTIAL. SHOULD LLVL MOISTURE BE OVERDONE IN NEAR TERM MESO MODELS...SHEAR MAY OVERWHELM CAPE AT LEAST FOR A TIME. ALL THE PREVIOUS PARAMETERS BEAR WATCHING. STRONG 0-1 KM SHEAR...STORM RELATIVE HELICITY IN EXCESS OF 250 M*2/S*2... LOW LCLS AND BLOSSOMING CAPES POTENTIALLY IN EXCESS OF 1500 J/KG...STRONG MOISTURE FLUX INTO THE MID TO LOWER SUSQ. VALLEY AFT 18Z AND EHIS BETWEEN 1 AND 2.5 SFC LATE THIS AFTERNOON AND EARLY THIS EVENING (FROM HRRR...RUC13 AND NAM12) ALL POINT TO SIGNIFICANTLY ELEVATED SVR AND TOR THREAT. SPOKE WITH SPC AND ONE LIMITING FACTOR MAY BE BOUNDARY LAYER MOISTURE AS SFC DEWPOINTS ARE CURRENTLY LINGERING AROUND THE LOWER 60S IN THE WARM SECTOR. THIS IS PRE-CONVECTION AND BEFORE STRONG MOISTURE FLUX IS SIMULATED TO ARRIVE AS PER 3KM HRRR. WILL CONTINUE TO WATCH CLOSELY. SLIGHTLY LESS LLVL MOISTURE MAY NOT YIELD LOW ENOUGH LCLS FOR TORS...BUT SRH WILL PROVIDE SUFFICIENT SHEAR/ROTATION FOR ORGANIZED SUPERCELLS AND AREAS OF WIND DAMAGE. INITIAL CELLS ARE NOW FIRING OFF ELEVATED HEAT SOURCES OVER BEDFORD...FULTON AND FRANKLIN COUNTIES AS EXPECTED. THIS FIRST CLUSTER OF STORMS WILL CROSS THE MID SUSQ. RIVER VALLEY THIS AFTERNOON AND ANOTHER SHOULD FORM ALONG THE COLD FRONT ITSELF...LIKELY TRACKING ACROSS THE SAME AREAS AS THE PREVIOUS CONVECTION TRAVERSED. THEREFORE...FLASH FLOOD WATCH FOR THE MID SUSQ. RIVER VALLEY IS STILL LOOKING REALLY GOOD. OPTED TO EXPAND FURTHER SOUTH THROUGH SCHUYLKILL...DAUPHIN...JUNIATA... PERRY AND CUMBERLAND COUNTIES. AS THE LOW LIFTS NE OF THE STATE TONIGHT...THE TRAILING STRONG COLD FRONT WILL PUSH EAST ACROSS THE SUSQ VALLEY. STEADY RAIN AND TSRA WILL GRADUALLY DIMINISH ACROSS THE EASTERN PART OF THE CWA AS UNSEASONABLY COLD AIR SURGES INTO THE COMMONWEALTH. 850 MB TEMPS DIPPING TO -2 TO -3C BY 12Z WED ACROSS THE LAURELS AND NW MTNS WILL BE COLD ENOUGH TO SUPPORT AT LEAST SOME WET SNOWFLAKES MIXING IN WITH THE LINGERING RAIN SHOWERS. ELSEWHERE...RAIN SHOWERS WILL OCCUR THROUGH DAYBREAK WED. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... THE UPPER LOW MOVING ACROSS THE AREA WILL KEEP SOME SHOWERS ACROSS THE AREA ON WED...ESPECIALLY DURING THE MORNING HOURS. TOOK OUT SNOW FOR WED MORNING...NOT REALLY COLD ENOUGH. TEMPS WILL BE BELOW NORMAL. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... DID NOT MAKE MANY CHANGES. STILL EXPECT SOME SHOWERS WED NIGHT...GIVEN DEFORMATION ZONE WITH THE UPPER LEVEL LOW. TEMPS COLD ENOUGH FOR SOME WET SNOW ACROSS THE HIGHER ELEVATIONS. FOR THU...WILL START OUT CLDY AND BREEZY...BUT SHOULD BE DRY AND NOT A BAD DAY. TEMPS STILL A FEW DEGREES BELOW NORMAL A CHC OF SHOWERS ON FRIDAY...WITH WEAK SYSTEM MOVING ACROSS THE AREA. STILL THINK MOST OF SATURDAY WILL BE DRY WITH WEAK RIDGING. THERE WILL BE A CHC OF SHOWERS ON SUNDAY...BEST CHC ACROSS THE FAR SW...AS A SYSTEM MOVES SOUTH OF PA. DECIDED TO KEEP MOST OF MONDAY INTO TUE DRY. A LOT OF SPREAD IN MODEL SOLUTIONS...BUT THINK THERE IS ENOUGH HINTS THAT WARM FRONT WILL STAY SOUTH AND WEST OF CENTRAL PA. VERY WARM AIR BUILDING ACROSS THE PLAINS IS OF CONCERN... SOMETHING TO WATCH...AS IT COULD BUST MAX TEMP FCST...AND ALSO BE A SOURCE OF AN ELEVATED MIXED LAYER FOR POINTS EAST. REGARDLESS OF WHERE THE WARM FRONT STALLS...THERE COULD AN INTENSE TEMP GRADIENT ACROSS IT...WITH SOME ACTIVE WEATHER. SOMETHING TO WATCH IN THE UPCOMING WEEK. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... NEARLY STATIONARY FRONTAL BOUNDARY STRETCHING SW-NE ACROSS CENTRAL PENNSYLVANIA EARLY THIS AFTERNOON WILL SLOWLY MOVE EASTWARD THIS AFTERNOON AND EVENING. A WAVE OF LOW PRESSURE MOVING ALONG IT WILL BRING AN INCREASE IN SHOWERS AND THUNDERSTORMS TO MUCH OF THE AREA THIS LATE AFTERNOON AND EVENING. BFD HAS BEEN IN THE COLDER AIR ALL DAY...THUS JUST SHOWERS THERE. OVERALL...LOOKING AT MVFR AND AT TIMES IFR CONDITIONS INTO EARLY WED...BEFORE CONDITIONS GRADUALLY BEGIN TO IMPROVE. OUTLOOK... WED...IFR-MVFR WITH LLWS POSSIBLE...IMPROVING CONDITIONS LATE. THU...NO SIG WX EXPECTED. FRI-SUN...MAINLY VFR. INTERMITTANT MVFR CIGS IN SCT SHRA. && .CTP WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH THROUGH WEDNESDAY MORNING FOR PAZ006-012-018- 019-025>028-034>037-041-042-045-046-049>053-056>059-063. && SYNOPSIS...DEVOIR/LAMBERT NEAR TERM...DEVOIR/MARTIN SHORT TERM...MARTIN LONG TERM...MARTIN AVIATION...DEVOIR/MARTIN/RXR
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 421 PM EDT TUE MAY 3 2011 PAZ004-005-010-011-017-042030- WARREN-MCKEAN-ELK-CAMERON-CLEARFIELD- 421 PM EDT TUE MAY 3 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT. WIDESPREAD RAINFALL OF 1 TO 2 INCHES WILL PRODUCE MINOR FLOODING OF POOR DRAINAGE AREAS THIS AFTERNOON AND TONIGHT. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED A THIS TIME. PAZ012-018-042030- NORTHERN CLINTON-NORTHERN CENTRE- 421 PM EDT TUE MAY 3 2011 ...FLASH FLOOD WATCH IN EFFECT THROUGH WEDNESDAY MORNING... ...SEVERE THUNDERSTORM WATCH 263 IN EFFECT UNTIL 10 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. FLASH FLOOD WATCH. SEVERE THUNDERSTORM WATCH. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLASH FLOOD WATCH. A FLASH FLOOD WATCH IS IN EFFECT UNTIL 8 AM WEDNESDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT HEAVY RAINFALL...HAIL...AND STRONG WINDS. PAZ006-042030- POTTER- 421 PM EDT TUE MAY 3 2011 ...FLASH FLOOD WATCH IN EFFECT THROUGH WEDNESDAY 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. FLASH FLOOD WATCH. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLASH FLOOD WATCH. A FLASH FLOOD WATCH IS IN EFFECT UNTIL 8 AM WEDNESDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT HEAVY RAINFALL. PAZ019-026>028-034>036-045-056>059-063-042030- SOUTHERN CENTRE-HUNTINGDON-MIFFLIN-JUNIATA-BEDFORD-FULTON-FRANKLIN- SOUTHERN CLINTON-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-CUMBERLAND- 421 PM EDT TUE MAY 3 2011 ...FLASH FLOOD WATCH IN EFFECT THROUGH WEDNESDAY MORNING... ...SEVERE THUNDERSTORM WATCH 263 IN EFFECT UNTIL 10 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. FLASH FLOOD WATCH. SEVERE THUNDERSTORM WATCH. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLASH FLOOD WATCH. A FLASH FLOOD WATCH IS IN EFFECT UNTIL 8 AM WEDNESDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT HEAVY RAINFALL...HAIL...AND STRONG WINDS. PAZ024-033-042030- CAMBRIA-SOMERSET- 421 PM EDT TUE MAY 3 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT. THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED. PAZ064>066-042030- ADAMS-YORK-LANCASTER- 421 PM EDT TUE MAY 3 2011 ...SEVERE THUNDERSTORM WATCH 263 IN EFFECT UNTIL 10 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...WEDNESDAY THROUGH MONDAY. THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT HEAVY RAINFALL...HAIL...AND STRONG WINDS. PAZ025-042030- BLAIR- 421 PM EDT TUE MAY 3 2011 ...FLASH FLOOD WATCH IN EFFECT THROUGH WEDNESDAY 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. FLASH FLOOD WATCH. IN ADDITION...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT. THE MAIN SEVERE WEATHER THREAT WILL BE IN THE FORM OF STRONG...AND POSSIBLY LOCALIZED DAMAGING WIND GUSTS AND ISOLATED OCCURRENCES OF LARGE HAIL. HOWEVER...STRONG AND VEERING WINDS JUST A FEW THOUSAND FEET ABOVE GROUND COULD LEAD TO A FEW ISOLATED TORNADOES ACCOMPANYING THE STRONGER THUNDERSTORMS ACROSS THE MIDDLE SUSQUEHANNA VALLEY. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLASH FLOOD WATCH. A FLASH FLOOD WATCH IS IN EFFECT UNTIL 8 AM WEDNESDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT HEAVY RAINFALL...HAIL...AND STRONG WINDS. PAZ037-041-042-046-049>053-042030- TIOGA-NORTHERN LYCOMING-SULLIVAN-SOUTHERN LYCOMING-UNION-SNYDER- MONTOUR-NORTHUMBERLAND-COLUMBIA- 421 PM EDT TUE MAY 3 2011 ...FLASH FLOOD WATCH IN EFFECT THROUGH WEDNESDAY MORNING... ...SEVERE THUNDERSTORM WATCH 263 IN EFFECT UNTIL 10 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. FLASH FLOOD WATCH. SEVERE THUNDERSTORM WATCH. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY. PLEASE LISTEN TO NOAA WEATHER RADIO OR GO TO WEATHER.GOV/STATECOLLEGE ON THE INTERNET FOR MORE INFORMATION ABOUT THE FOLLOWING HAZARDS. FLASH FLOOD WATCH. A FLASH FLOOD WATCH IS IN EFFECT UNTIL 8 AM WEDNESDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT HEAVY RAINFALL...HAIL...AND STRONG WINDS. MARTIN
The State College radar (KCCX), 46 km away, was scanning. The volume nearest the first event began at 21:01 UTC.
4 flash flood, 2 thunderstorm wind. Local standard time, as filed.
Flash flooding closed Sugar Grove Road east of Huntingdon in Henderson Township.
Flash flooding closed PA 26 at the intersection of PA 164 between Martinsburg and Saxton.
Flash flooding closed Back Maitland Road (SR 2004) in Derry Township northeast of Lewistown.
Flash flooding closed Ridge Road (SR 4004) in West Beaver Township near McClure.
Thunderstorm winds estimated near 60 mph knocked down trees in Riverside.
Thunderstorm winds estimated near 60 mph knocked down a barn and trapped 40 cattle inside. The winds also knocked down five large pine trees.
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, May 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: 292862, 292863, 292864, 292865, 288384, 288382.