Strong to severe thunderstorms developed over the upper Ohio Valley during the day on May 31st ahead of surface low pressure that would cross the region in the evening. With moderate instability and shear, several storms produced severe 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 PBZ wrote it up.
Strong to severe thunderstorms developed over the upper Ohio Valley during the day on May 31st ahead of surface low pressure that would cross the region in the evening. With moderate instability and shear, several storms produced severe wind damage. In addition, where shear was enhanced near a stationary boundary, a brief EF-0 tornado touched down in Hermitage, Mercer county Pennsylvania. Damage occurred at and around the Sheetz in Hermitage and a truck was flipped onto it's side in the parking lot.
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 Pittsburgh, PA wrote its last area forecast discussion before the first event at May 31, 2:32 PM EST, 2 hours 38 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 332 PM EDT SUN MAY 31 2015 .SYNOPSIS... LOW PRESSURE WILL CROSS THE UPPER OHIO VALLEY REGION THIS EVENING...WITH COOLER TEMPERATURES IN ITS WAKE EARLY THIS WEEK. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... LOW PRESSURE TRACKING ACROSS THE UPPER OHIO VALLEY WILL CONTINUE TO BRING SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS TO THE AREA THIS EVENING...WITH THE MOST NUMEROUS IN VICINITY OF A SURFACE BOUNDARY NEAR THE I 80 CORRIDOR WHERE THE BEST...ALBEIT WEAK...SHEAR EXISTS. THIS LACK OF SHEAR HAS ALLOWED FOR DISORGANIZED DEVELOPMENT OF STORMS...WITH AN OCCASIONAL PULSE TYPE SEVERE STORM NEAR I 80. EVEN THIS THREAT SHOULD QUICKLY DIMINISH BY THIS EVENING. STRATUS/STRATOCU SHOULD CONTINUE BEHIND THE DEPARTING LOW/SURFACE BOUNDARY TONIGHT. LOWS NEAR OR JUST BELOW AVERAGE ARE EXPECTED. && .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/... THE BOUDARY SHOULD STALL JUST EAST OF THE AREA MONDAY. AN UPPER TROUGH ADVANCING ACROSS THE AREA SHOULD KEEP SHOWERS CHANCES IN THE AREAS ESPECIALLY IN THE AFTERNOON. A CUTOFF UPPER LOW ACROSS THE TN/MS VALLEY REGIONS...WHICH WILL KEEP CLOUDS AND OCCASIONAL SHOWER CHANCES ESPECIALLY FROM PIT SOUTH INTO MID WEEK. TEMPERATURES ARE EXPECTED TO AVERAGE NEAR OR JUST BELOW AVERAGE USING THE LATEST SREF AND GRIDDED MOS NUMBERS. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... BY THURSDAY AFTERNOON THAT UPPER LOW WILL BRING INCREASED SHOWER AND THUNDERSTORM CHANCES EACH AFTERNOON INTO THE EARLY PART OF THE WEEKEND. A WARMING TREND WILL ALSO CONTINUE THROUGH THE END OF THE WEEK WITH TEMPERATURES ONCE AGAIN WELL ABOVE AVERAGE. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... CROSSING LOW PRESSURE IS EXPECTED TO BRING SHOWER AND THUNDERSTORM CHANCES THIS AFTERNOON INTO EARLY EVENING. BRIEF MVFR TO IFR RESTRICTIONS ARE POSSIBLE IN ANY OF THE STORMS. THE LOW IS EXPECTED TO SHIFT EAST OF THE AREA TONIGHT DRAGGING A COLD FRONT THROUGH. WIDESPREAD MVFR TO IFR CONDITIONS ARE EXPECTED BEHIND THE FRONT...CONTINUING INTO MONDAY. .OUTLOOK.../MONDAY NIGHT THROUGH THURSDAY/... RESTRICTIONS COULD PERSIST THROUGH MONDAY NIGHT. RESTRICTION POTENTIAL COULD RETURN BY MID WEEK WITH UPPER LEVEL LOW PRESSURE. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && 07
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE PITTSBURGH PA 338 PM EDT SUN MAY 31 2015 PAZ007>009-013>016-022-023-011945- MERCER-VENANGO-FOREST-LAWRENCE-BUTLER-CLARION-JEFFERSON PA-ARMSTRONG- INDIANA- 338 PM EDT SUN MAY 31 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHWEST PENNSYLVANIA AND WEST CENTRAL PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE THROUGH EARLY THIS EVENING. THE MAIN THREATS ARE DAMAGING WINDS AND LARGE HAIL. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ020-021-029-031-073>076- WVZ001>004-012-021>023-041-011945- GARRETT-TUSCARAWAS-CARROLL-COLUMBIANA-COSHOCTON-HARRISON- JEFFERSON OH-MUSKINGUM-GUERNSEY-BELMONT-NOBLE-MONROE-BEAVER- ALLEGHENY-WASHINGTON-GREENE-WESTMORELAND-WESTMORELAND RIDGES-FAYETTE- FAYETTE RIDGES-HANCOCK-BROOKE-OHIO-MARSHALL-WETZEL-MARION-MONONGALIA- PRESTON-TUCKER- 338 PM EDT SUN MAY 31 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MARYLAND...EAST CENTRAL OHIO...SOUTHWEST PENNSYLVANIA...NORTHERN WEST VIRGINIA AND NORTHERN PANHANDLE OF WEST VIRGINIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. 07
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PITTSBURGH PA
220 PM EDT SUN MAY 31 2015
PAZ009-015-016-311845-
JEFFERSON-CLARION-FOREST-
220 PM EDT SUN MAY 31 2015
...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN JEFFERSON...EASTERN
FOREST AND NORTHEASTERN CLARION COUNTIES...
AT 219 PM EDT...A STRONG THUNDERSTORM WAS 10 MILES SOUTHWEST OF
MARIENVILLE...MOVING NORTHEAST AT 35 MPH.
WIND GUSTS UP TO 50 MPH AND NICKEL SIZE HAIL ARE POSSIBLE WITH THIS
STORM.
LOCATIONS IMPACTED INCLUDE...
MARIENVILLE...LEEPER...FISHER...COOK FOREST STATE PARK...CLEAR CREEK
STATE PARK AND CLARINGTON.
LAT...LON 4144 7896 4144 7897 4145 7898 4145 7906
4142 7907 4142 7909 4134 7909 4135 7908
4136 7903 4135 7902 4138 7897 4136 7895
4123 7923 4137 7937 4163 7900 4163 7896
TIME...MOT...LOC 1819Z 233DEG 29KT 4135 7923
34PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
226 PM EDT SUN MAY 31 2015
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0208 PM HAIL 8 WNW SIGEL 41.33N 79.26W
05/31/2015 M0.88 INCH CLARION PA TRAINED SPOTTER
&&
JDPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
322 PM EDT SUN MAY 31 2015
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0247 PM HAIL 3 SW SIGEL 41.25N 79.15W
05/31/2015 M0.88 INCH JEFFERSON PA TRAINED SPOTTER
&&
NWS PITTSBURGH PA
IRIS SYSTEMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
450 PM EDT SUN MAY 31 2015
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0401 PM TSTM WND DMG 2 N WEST MIDDLESEX 41.20N 80.46W
05/31/2015 MERCER PA 911 CALL CENTER
PART OF SHEETZ GAS STATION CANOPY RIPPED OFF
AND DAMAGED. 2 VEHICLES WERE FLIPPED ON
THEIR SIDE AT THE GAS STATION. SEVERE TREES
WERE ALSO DOWN IN THE TOWN OF HERMITAGE.
&&
24PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PITTSBURGH PA
523 PM EDT SUN MAY 31 2015
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0121 PM FLOOD SHARON 41.23N 80.49W
05/31/2015 MERCER PA PUBLIC
PICTURE SHOWS CONNELLY ROAD FLOODED ON A LOW
SPOT WITH WATER UP TO SOME OF THE HOODS OF
CARS.
&&
NWS PITTSBURGH PA
IRIS SYSTEMPRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE PITTSBURGH PA
541 PM EDT SUN MAY 31 2015
...TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
...DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0401 PM TSTM WND DMG 2 N WEST MIDDLESEX 41.20N 80.46W
05/31/2015 MERCER PA 911 CALL CENTER
PART OF SHEETZ GAS STATION CANOPY RIPPED OFF
AND DAMAGED. 2 VEHICLES WERE FLIPPED ON
THEIR SIDE AT THE GAS STATION. SEVERAL TREES
WERE ALSO DOWN IN THE TOWN OF HERMITAGE. (CORRECTED REMARKS)
&&
NWS PITTSBURGH PA
IRIS SYSTEMThe Pittsburgh radar (KPBZ), 117 km away, was scanning. The volume nearest the first event began at 22:10 UTC.
3 thunderstorm wind. Local standard time, as filed.
State official reported trees down around the city of Fairmont including one on Palatine Ave and Moyer way.
State official reported a tree down on Sugar Lane near Rivesville.
Local media reported partial roof damage to a Napa Auto Parts building on route 7 in Sabraton.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in West Virginia in 2015Every state in 2015This day in weather historyWarnings in West Virginia, 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: 582560, 582561, 582562.