Tornadoes · United States · Pennsylvania · 2012
EF0 tornado, Inez to Sweden Vly, Pennsylvania, May 2, 2012
From Inez to Sweden Vly, this EF0 tornado ran 0.4 miles across Potter County on May 2, 2012, touching down at 9:15 PM EDT and reaching 25 yards wide. It killed nobody, and did $75,000 of property damage.
The rating scale
Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.
The record
- Rating
- EF0
- Date
- May 2, 2012
- Touchdown
- 9:15 PM EDT (01:15 UTC)
- Lifted
- 9:16 PM EDT (01:16 UTC)
- On the ground
- 1 minutes
- Path length
- 0.4 miles (0.6 km)
- Path width
- 25 yards (23 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $75,000
- County
- Potter County
- Touchdown point
- 41.729, -77.973
- Lift-off point
- 41.731, -77.966
- Record number
- 1205021915-01
What the Weather Service recorded
A cluster of Severe Thunderstorms moved across the northern tier of Central Pennsylvania during the evening hours of May 2nd, producing large hail and pockets of wind damage. A weak EF0 tornado was also confirmed in Potter County near Ayers Hill.
Severe thunderstorms spawned a brief tornado near Ayers Hill. A survey team consisting of the National Weather Service and County Emergency Management concluded that the tornado touched down near the intersection of Cherry Tree Lane and First Fork Road /SR 3003/ just west of Ayers Hill. The tornado moved east-northeast intermittently touching down for about a half mile before lifting near Gates Hill Road. There were several witnesses who saw a funnel cloud prior to taking shelter in their homes. Damage included uprooting about 30 trees, damaging two barns, and producing some minor roof damage to 4 homes. In addition, a large trailer was overturned, totaling two vehicles which it landed on. A vehicle was blown off First Fork Road as the tornado moved overhead. Peak winds were estimated at 75 mph, making the tornado an EF0. There were no injuries or fatalities.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 00:38 UTC | 01:30 UTC | Severe Thunderstorm Warning | CTP |
| 00:58 UTC | 02:00 UTC | Severe Thunderstorm Warning | CTP |
| 01:19 UTC | 04:15 UTC | Flood Advisory | CTP |
| 01:56 UTC | 02:30 UTC | Severe Thunderstorm Warning | CTP |
Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.
The forecast that day
The Storm Prediction Center had this point in a Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:56 UTC.
SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.
The air that afternoon
The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.
Buffalo Intl Airport, NY (KBUF), 00:00Z
1.3 hours before the tornado, 146 km from the path. May 3, 2012.
- Mixed-layer CAPE
- 849 J/kg
- Mixed-layer CIN
- -27 J/kg
- Surface CAPE
- 431 J/kg
- Mixed-layer LCL
- 1045 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 349 m²/s²
- 0-3 km storm-relative helicity
- 527 m²/s²
- Significant tornado parameter
- 2.1
- Supercell composite
- 13.2
- 0-3 km lapse rate
- 6.7 K/km
Buffalo Intl Airport, NY (KBUF), 12:00Z
10.7 hours after it, 146 km from the path. May 3, 2012.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -76797 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 775 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 20 m²/s²
- 0-3 km storm-relative helicity
- 12 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 2.7 K/km
The surface observations
Wellsville Municipal (ELZ), 42 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 23:56 UTC | 71 | 58 | 6 kt | 1015.2 | VCTS | |
| 00:56 UTC | 68 | 61 | 220° 8 kt | 1015.9 | VCTS -RA | |
| 01:15 UTC | 66.2 | 60.8 | 230° 7 kt | 1016.3 | VCTS -RA | |
| 01:39 UTC | 66.2 | 62.6 | 10° 8 kt | 1016.9 | -RA | |
| 01:56 UTC | 66 | 62 | 0° 0 kt | 1016.9 | -RA | |
| 02:56 UTC | 66 | 61 | 230° 7 kt | 1016.9 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The State College radar (KCCX), 90 km away, was scanning. The volume nearest the touchdown began at 01:13 UTC.
Open the radar archive at this moment, over the track
Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 00:46 UTC | TSTM WND DMG | 2 S Coryville | Mckean, PA | TREES AND POWER LINES DOWN ON ROUTE 446 IN KEATING TWP. |
| 01:05 UTC | HAIL 1 | Galeton | Potter, PA | QUARTER-SIZED HAIL. |
| 01:15 UTC | TSTM WND DMG | 4 Sse Coudersport | Potter, PA | TREES DOWN AND A CAMPER BLOWN OVER NEAR THE HOMER AND SUMMIT TWP LINE. |
| 01:15 UTC | TORNADO | Ayers Hill | Potter, PA | A STORM SURVEY CONDUCTED BY THE NWS STATE COLLEGE CONFIRMS A BRIEF EF0 TORNADO NEAR AYERS HILL. MAX WINDS 75 MPH. FOUR HOMES AND TWO VEHICLES SUSTAINED DAMAGE ALONG THE HALF-MILE PATH OF THE TORNADO. NO INJURIES WERE REP |
| 01:18 UTC | TSTM WND DMG | Ayers Hill | Potter, PA | TREES REPORTED DOWN IN SUMMIT TWP. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2012 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are
The other tornadoes of May 2, 2012
1 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 2 | 10:03 PM CDT | EF1 | Thayer, NE | 1.0 | 250 | $200,000 |
What this means
Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.
Sources
NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.