Severe thunderstorms developed across central Pennsylvania as an area of low pressure traveled along a stationary frontal boundary that was draped across the area. A flash flood occurred in Schuylkill County.
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 thunderstorms developed across central Pennsylvania as an area of low pressure traveled along a stationary frontal boundary that was draped across the area. A flash flood occurred in Schuylkill County.
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 31, 9:26 AM EST, 1 hour 49 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 1026 AM EDT SUN MAY 31 2015 .SYNOPSIS... WE ARE UNDER A SLIGHT RISK FOR SEVERE THUNDERSTORMS TODAY AHEAD OF A COLD FRONT THAT WILL SAG SLOWLY SOUTH THROUGH THE REGION TODAY AND TONIGHT. COOLER CONDITIONS WITH LINGERING SHOWERS WILL FOLLOW FOR MONDAY...WITH MUCH COOLER WEATHER SLATED FOR THE MID AND LATE WEEK PERIOD. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 9AM THE COLD FRONT WAS JUST NORTH OF I-80 WITH MOST OF THE FCST AREA UNDER A WARM-HUMID AND INCREASINGLY UNSTABLE AIRMASS. SHORT RANGE HIGH RES GUIDANCE SHOWS THE FRONT DROPPING INTO CENTRAL PARTS OF THE FCST AREA BY MID AFTERNOON...AND THIS IS EXPECTED TO ACT AS THE FOCUS FOR CONVECTION. STRONG HEATING SOUTH OF THE WARM FRONT WILL HELP BOOST CAPES TO BETWEEN ABOUT 1000-1500J IN THE VERY HUMID AIRMASS...PWATS 1-3 STD DEV ABOVE NORMAL. WIND SHEAR IS MARGINAL BUT SHOULD BECOME A BIT MORE ROBUST WITH THE APPROACH OF AN MCV CURRENTLY MOVING OUT OF EASTERN OHIO. RAP SHOWS HIGHER HELICITY AIR FOCUSED ALONG THE EXPECTED POSITION OF THE FRONTAL BOUNDARY THROUGH THE AFTERNOON...THOUGH IT'S NOT INCREDIBLY HIGH SO THE RISK FOR TORNADOES SHOULD BE LOW. THE BIGGEST RISK WILL BE FOR DOWNBURSTS GUSTS AND LOCALLY TORRENTIAL RAINS. 8H TEMPS SOUTH OF THE FRONT WILL REMAIN WARM ENOUGH TO SUPPORT HIGHS IN THE M80S ACROSS THE SOUTHERN VALLEYS. HOWEVER...HEATING OF MOIST/UNSTABLE AIR MASS...COMBINED WITH APPROACH OF SHORTWAVE LIFTING OUT OF OHIO...SHOULD TRIGGER CONVECTION ACROSS THE CENTRAL COUNTIES BY MIDDAY...THUS HOLDING TEMPS DOWN IN THIS AREA TO THE 75-80F RANGE. NORTH OF THE FRONT...LOW LVL CAA...COMBINED WITH CLOUD COVER...WILL LIKELY HOLD TEMPS IN THE L60S ALONG THE NY BORDER. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... SOUTH OF THE APPROACHING CFRONT...CONVECTIVE ENVIRONMENT CHARACTERIZED BY MODERATE CAPE AND RELATIVELY WEAK SHEAR. THUS...WIDESPREAD/ORGANIZED SVR WX SEEMS UNLIKELY. HOWEVER...THE SLOW MOVING NATURE OF THE FRONT COULD ENHANCE THE POTENTIAL FOR LOCALLY HEAVY RAINS. CONVECTION-ALLOWING MDLS HAVE BEEN ADVERTISING THE LIKELIHOOD OF LOCAL AMTS NR 2 INCHES. HOWEVER...GIVEN OUR DRY STRETCH OF WX...THE FLOODING THREAT DOES/T APPEAR ESPECIALLY HIGH. MDL CONSENSUS PLACES THE BEST CHC OF SHRA/TSRA AND GREATEST MEAN QPF ALONG AND JUST S OF FRONT...SPANNING THE CENTRAL COUNTIES ALONG I-80. POPS RANGE FROM LIKELY IN THE NORTH TO CATEGORICAL ACROSS CENTRAL AND SOUTHERN PA SUN AFTN. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... SURFACE FRONT IS MADE TO STALL OVER SRN PA WITH A WAVE OR SEVERAL WAVES RIPPLING ALONG IT INTO EARLY NEXT WEEK. PERSISTENT FORCING AND RICH MOISTURE FEED WITH PW IN THE 1.33" TO 1.8" RANGE BRING THE BEST CHANCE OF WIDESPREAD RAINFALL THAT WE'VE SEEN IN QUITE SOME TIME. STRONGER 0-1KM SW TO SOUTHERLY WINDS AT 850 MB AND WINDS WITH A VEERING PROFILE WILL COMBINE WITH QUITE LOW LCLS TO ENHANCE SPC/S MARGINAL SVR WEATHER THREAT. TO THE NORTH OF THE FRONT...GUIDANCE REMAINS CONSISTENT ON COOLING THINGS DOWN ACROSS NORTH CENTRAL PA...WITH EVEN SOME SIGNIFICANT DRYING POSSIBLE AS DEWPOINTS POTENTIALLY DROP INTO THE 40S. TOO EARLY TO GET HUNG UP ON THE DETAILS AS THEY WILL CHANGE...BUT AS PREVIOUSLY MENTIONED...A COUPLE DAYS OF CLOUDY...COOL AND SHOWERY WX APPEARS ON TAP FOR CENTRAL PA WITH THE STALLED FRONT AND FREQUENT SHOWERS AND CHC OF THUNDERSTORMS. A SLOW DRYING TREND BEGINS BY TUESDAY AS RICH PW PLUME SHIFTS OFFSHORE AND SEVERAL DAYS OF COMFORTABLE TEMPERATURE AND HUMIDITY LEVELS AND LOWER POPS APPEAR TO BE IN THE OFFING. && .AVIATION /14Z SUNDAY THROUGH THURSDAY/... NORTHERN TERMINALS...NORTH OF THE SLOW MOVING COLD FRONT ARE UNDER A SHIELD OF LOW CLOUDS WITH PASSING SHOWERS AND AREAS OF FOG. SOUTH OF THE FRONT...SOME MVFR CLOUDS CONTINUE OVER PARTS OF THE MIDDLE SUSQ VALLEY BUT MOST TERMINALS ARE VFR AND A BIT HAZY. IT WILL BECOME MORE UNSTABLE AS THE DAY MATURES...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO INCREASE IN COVERAGE WITH DAYTIME HEATING. TRIED TO DEPICT MOST LIKELY TIMING FOR TSTMS BASED ON HRRR/COSPA IN 2HR TEMPO GROUPS DURING THE MID- LATE AFTN. SOME STORMS MAY BE SVR CAUSING BRIEF PERIODS OF LIFR. MORE WIDESPREAD RESTRICTIONS ARE PROBABLE TONIGHT INTO MONDAY/TUESDAY...NORTH OF THE FRONT AS IT SAGS SLOWLY INTO THE MID ATL STATES. OUTLOOK... WED-THU...MAINLY VFR. NO SIG WX. && .CTP WATCHES/WARNINGS/ADVISORIES... NONE. && SYNOPSIS...LA CORTE/LAMBERT NEAR TERM...LA CORTE/LAMBERT SHORT TERM...FITZGERALD/LAMBERT LONG TERM...ROSS/GARTNER AVIATION...LA CORTE/STEINBUGL
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 437 AM EDT SUN MAY 31 2015 PAZ010>012-017>019-024>028-033>035-045-046-049>053-056>059-063- 010845- ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD-NORTHERN CENTRE- SOUTHERN CENTRE-CAMBRIA-BLAIR-HUNTINGDON-MIFFLIN-JUNIATA-SOMERSET- BEDFORD-FULTON-SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER- MONTOUR-NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON- CUMBERLAND- 437 AM EDT SUN MAY 31 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TODAY AND TONIGHT. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING. A SLOW MOVING COLD FRONT WILL STALL OUT ALONG INTERSTATE 80 LATE TODAY. THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND FREQUENCY ALONG...AND JUST TO THE NORTH OF THE BOUNDARY THIS AFTERNOON...WITH SOME STORMS CONTAINING LOCALIZED DAMAGING WIND GUSTS AND HAIL. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. PAZ004>006-037-041-042-010845- WARREN-MCKEAN-POTTER-TIOGA-NORTHERN LYCOMING-SULLIVAN- 437 AM EDT SUN MAY 31 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TODAY AND TONIGHT. THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING. A SLOW MOVING COLD FRONT WILL STALL OUT ALONG INTERSTATE 80 LATE TODAY. SHOWERS AND SCATTERED THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND FREQUENCY ALONG THE FRONTAL BOUNDARY THIS AFTERNOON...WITH A FEW OF THE STORMS CONTAINING LOCALIZED DAMAGING WIND GUSTS AND HAIL. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. PAZ036-064>066-010845- FRANKLIN-ADAMS-YORK-LANCASTER- 437 AM EDT SUN MAY 31 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TODAY AND TONIGHT. ISOLATED STRONG THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND EVENING. A FEW OF THE STORMS COULD CONTAIN WIND GUSTS OF 40 TO 50 MPH...HAIL...AND FREQUENT CLOUD TO GROUND LIGHTNING .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS MONDAY AFTERNOON AND EVENING AS A SLOW MOVING COLD FRONT PUSHES SOUTHEAST ACROSS THE REGION. THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND FREQUENCY ALONG...AND JUST TO THE NORTH OF THE BOUNDARY THIS AFTERNOON...WITH SOME STORMS CONTAINING LOCALIZED DAMAGING WIND GUSTS AND HAIL. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. LAMBERT
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1122 AM EDT SUN MAY 31 2015
PAZ004-005-311545-
WARREN PA-MCKEAN PA-
1122 AM EDT SUN MAY 31 2015
...SPECIAL WEATHER STATEMENT...
AT 1120 AM EDT...DOPPLER RADAR INDICATED AN AREA OF SHOWERS AND
THUNDERSTORMS MOVING NORTHEAST THROUGH WARREN AND MCKEAN COUNTIES.
TORRENTIAL DOWNPOURS WILL ACCOMPANY SOME OF THESE SHOWERS AND
THUNDERSTORMS AS THEY MOVE OVER THE AREA THROUGH EARLY AFTERNOON.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
MINOR FLOODING MAY DEVELOP. DO NOT DRIVE INTO WATER COVERING THE
ROADWAY.
&&
LAT...LON 4200 7831 4185 7821 4163 7902 4163 7950
4164 7959 4199 7957
TIME...MOT...LOC 1520Z 240DEG 49KT 4176 7910
LA CORTEThe State College radar (KCCX), 83 km away, was scanning. The volume nearest the first event began at 16:13 UTC.
13 thunderstorm wind, 5 hail, 1 flash flood. Local standard time, as filed.
Thunderstorm winds estimated near 60 mph produced sporadic wind damage across western Elk County.
Thunderstorm winds estimated near 60 mph knocked down trees and wires near the intersection of Great Cove and Timber Ridge Roads near Needmore.
Thunderstorm winds estimated near 60 mph knocked down trees in North Centre Township.
Thunderstorm winds estimated near 60 mph produced sporadic tree damage from Boiling Springs to Mechanicsburg.
Thunderstorm winds estimated near 60 mph knocked down trees and wires near Allen.
Thunderstorm winds estimated near 60 mph knocked down trees in Hoernerstown.
Thunderstorm winds estimated near 60 mph knocked down trees and wires near Palmyra.
Thunderstorm winds estimated near 60 mph knocked down trees and wires near Campbelltown.
Thunderstorm winds estimated near 60 mph knocked down trees and wires near Palmyra.
Thunderstorm winds estimated near 60 mph knocked down numerous large branches near Hershey.
Thunderstorm winds estimated near 60 mph knocked down trees near Bachmanville.
Thunderstorm winds estimated near 60 mph knocked down trees near Annville.
Several homes and a bank were flooded on Center and Progress Avenues in Schuylkill Haven.
Thunderstorm winds estimated near 60 mph knocked down trees and wires near Hebron.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2015Every state in 2015This day in weather historyWarnings in Pennsylvania, May 2015
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: 571388, 571370, 571377, 571373, 571374, 571378, 571375, 571376, 571381, 571389, 571379, 571380, 571382, 571383, 571386, 571387, 571384, 578537, 571385.