EF1 tornado, Inez to Sweden Vly, Pennsylvania, July 27, 2013

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. 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.

4. 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.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. 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.

7. 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.

Rating

EF1

Date

July 27, 2013

Touchdown

5:00 PM EDT (21:00 UTC)

Lifted

5:06 PM EDT (21:06 UTC)

On the ground

6 minutes

Path length

2.9 miles (4.7 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$30,000

County

Potter County

Touchdown point

41.677, -77.990

Lift-off point

41.714, -77.961

Record number

1307271500-01

11 damage points were recorded along this path by NWS CTP, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 100 mph.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

An isolated thunderstorm produced an EF1 tornado near Coudersport in Potter County. Another isolated storm produced wind damage in Perry County.

A National Weather Service survey team, along with Potter County Emergency Management Officials, confirmed that an EF1 tornado touched down south of Coudersport during the late afternoon of July 27th. The EF1 tornado touched down just west of Big Moores Run Road in Homer Township and traveled to the northeast producing intermittent damage along a three mile path. The last observed damage was found along First Fork Road about one mile south of Ayers Hill. Damage was confined mainly to trees, however two homes sustained damage from the falling limbs and trees. The most significant tree damage occurred along Big Moores Run Road about 1 mile southeast of the intersection of Black Diamond Road and Big Moores Run Road. At this point, winds were estimated near 100 mph with numerous 12 diameter hardwood trees snapped and sheared-off. Elsewhere along the track, winds were estimated around 80 mph with lesser tree damage, confined mainly to toppled trees with shallower root balls. There were no injuries or fatalities.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

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 Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 19:56 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 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.

Wellsville Municipal (ELZ), 46 km from the path, in the two hours either side.

From the Iowa Environmental Mesonet's archive of airport observations.

The State College radar (KCCX), 86 km away, was scanning. The volume nearest the touchdown began at 20:58 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.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2013 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

2 more were confirmed in the United States that day.

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.