Tornadoes · United States · Pennsylvania · 2016

EF0 tornado, Zeno, Pennsylvania, August 25, 2016

This EF0 tornado ran 2.1 miles across Butler County on August 25, 2016, touching down at 9:43 PM EDT and reaching 350 yards wide. It killed nobody, and did $5,000 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.

  1. EF065 to 85 mphthis tornado

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

  2. EF186 to 110 mph

    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.

The record

Rating
EF0
Date
August 25, 2016
Touchdown
9:43 PM EDT (01:43 UTC)
Lifted
9:44 PM EDT (01:44 UTC)
On the ground
1 minutes
Path length
2.1 miles (3.3 km)
Path width
350 yards (320 m)
Deaths
0
Injuries
0
Property damage
$5,000
County
Butler County
Touchdown point
40.779, -80.028
Lift-off point
40.785, -79.989
Record number
1608251943-01

What the Weather Service recorded

As a shortwave moved across the eastern Great Lakes, a weak boundary moved south across western Pennsylvania. Thunderstorms developed along the boundary in the evening, with isolated severe thunderstorms. One storm produced a weak and brief EF0 tornado in southern Butler county.

A NWS Storm Survey found a brief EF0 tornado occurred east of Evans City. Damage was limited to broken large hardwood trees, shingles removed from several outbuildings, and a natural gas well pad blown onto a fence. The tornado was on the ground for nearly 2 miles, with a maximum width of 350 yards. The estimated maximum winds were near 80 MPH.

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

The warnings

0 minutes of warning. NWS PBZ issued a tornado warning for this county at 01:43 UTC, 0 minutes before the tornado touched down, in force until 02:01 UTC.

Issued (UTC)ExpiredProductOffice
01:43 UTC02:01 UTCTornado WarningPBZ
02:25 UTC03:15 UTCSevere Thunderstorm WarningPBZ

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 Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:51 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.

Pittsburgh, PA (KAGC), 00:00Z

1.7 hours before the tornado, 42 km from the path. August 26, 2016.

Skew-T log-pSkew-T log-p diagram, Pittsburgh, PA at 00:00Z on 2016-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1766 joules per kilogram, CIN -7, lifted condensation level 1083 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Pittsburgh, PA at 00:00Z on 2016-08-26The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 167 square meters per square second, 0 to 6 km bulk shear 30 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
1766 J/kg
Mixed-layer CIN
-7 J/kg
Surface CAPE
3144 J/kg
Mixed-layer LCL
1083 m above ground
0-6 km bulk shear
30 kt
0-1 km bulk shear
21 kt
0-1 km storm-relative helicity
167 m²/s²
0-3 km storm-relative helicity
249 m²/s²
Significant tornado parameter
1.2
Supercell composite
10.5
0-3 km lapse rate
7.0 K/km

Open this sounding in Storm Lab

Pittsburgh, PA (KAGC), 12:00Z

10.3 hours after it, 42 km from the path. August 26, 2016.

Skew-T log-pSkew-T log-p diagram, Pittsburgh, PA at 12:00Z on 2016-08-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 39 joules per kilogram, CIN -74, lifted condensation level 811 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Pittsburgh, PA at 12:00Z on 2016-08-26The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -17 square meters per square second, 0 to 6 km bulk shear 29 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
39 J/kg
Mixed-layer CIN
-74 J/kg
Surface CAPE
12 J/kg
Mixed-layer LCL
811 m above ground
0-6 km bulk shear
29 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0
0-3 km lapse rate
4.1 K/km

Open this sounding in Storm Lab

The radar

The Pittsburgh radar (KPBZ), 33 km away, was scanning. The volume nearest the touchdown began at 01:42 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)ReportWhereCountyRemark
01:43 UTCTSTM WND DMG3 Ene Evans CityButler, PATREES DOWN AT SPITHALER SCHOOL RD AND BROWNSDALE RD
01:47 UTCTORNADO3 Ene Evans CityButler, PAEF0 TORNADO
01:50 UTCTSTM WND DMG5 E Evans CityButler, PANEAR INTERSECTION OF REIBOLD AND BROWNSDALE ROADS. MULTIPLE TREES AND POWER LINES DOWN. DAMAGE TO THE ROOF OF BARN AND SHED.

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

This ground now

The live radar over the trackEvery 2016 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

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.