Tornadoes · United States · Pennsylvania · 2017

EF1 tornado, Smullton to Rebersburg, Pennsylvania, May 1, 2017

From Smullton to Rebersburg, this EF1 tornado ran 1.1 miles across Centre County on May 1, 2017, touching down at 6:44 PM EDT and reaching 100 yards wide. It killed nobody and injured 1, and did $200,000 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 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.

The record

Rating
EF1
Date
May 1, 2017
Touchdown
6:44 PM EDT (22:44 UTC)
Lifted
6:45 PM EDT (22:45 UTC)
On the ground
1 minutes
Path length
1.1 miles (1.8 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
1
Property damage
$200,000
County
Centre County
Touchdown point
40.939, -77.458
Lift-off point
40.947, -77.441
Record number
1705011644-01

What the Weather Service recorded

A strong cold front crossed central Pennsylvania during the late-afternoon and early evening hours of May , 2017. A quasi-linear convective system (QLCS) developed ahead of the front, and a handful of spin-ups along this line produced EF1 tornado damage. One of these spin-ups touched down near a wooden pallet factory on the outskirts of Rebersburg and moved rapidly northeastward before lifting just northeast of the town.

An EF1 tornado touched down near a wooden pallet factory on the outskirts of town and moved rapidly northeastward before lifting just northeast of the town. Damage occurred to several dozen homes and outbuildings across Rebersburg. Several dozen trees were either snapped or uprooted. One utility pole was also snapped. One injury occurred when a victim was trapped by the collapse of a work shed. Maximum wind speeds were estimated near 110 mph.

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.

The county was under a tornado watch, issued at 18:12 UTC and running to 02:00 UTC.

Issued (UTC)ExpiredProductOffice
18:12 UTC02:00 UTCTornado WatchCTP
20:52 UTC22:45 UTCSevere Thunderstorm WarningCTP
21:50 UTC00:45 UTCFlood AdvisoryCTP
22:44 UTC01:45 UTCFlood AdvisoryCTP
22:44 UTC23:30 UTCSevere Thunderstorm WarningCTP

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 Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:47 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.

Washington/Dulle, VA (KIAD), 12:00Z

10.7 hours before the tornado, 222 km from the path. May 1, 2017.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 2017-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -82430, lifted condensation level 805 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Washington/Dulle, VA at 12:00Z on 2017-05-01The 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 158 square meters per square second, 0 to 6 km bulk shear 37 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
0 J/kg
Mixed-layer CIN
-82430 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
805 m above ground
0-6 km bulk shear
37 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
158 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.9 K/km

Open this sounding in Storm Lab

Washington/Dulle, VA (KIAD), 00:00Z

1.3 hours after it, 222 km from the path. May 2, 2017.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 2017-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 403 joules per kilogram, CIN -25, lifted condensation level 913 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, Washington/Dulle, VA at 00:00Z on 2017-05-02The 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 195 square meters per square second, 0 to 6 km bulk shear 51 knots.1939587897Sfc1 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
403 J/kg
Mixed-layer CIN
-25 J/kg
Surface CAPE
483 J/kg
Mixed-layer LCL
913 m above ground
0-6 km bulk shear
51 kt
0-1 km bulk shear
22 kt
0-1 km storm-relative helicity
195 m²/s²
0-3 km storm-relative helicity
304 m²/s²
Significant tornado parameter
0.7
Supercell composite
1.9
0-3 km lapse rate
5.9 K/km

Open this sounding in Storm Lab

The surface observations

State College (UNV), 35 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:53 UTC75.262.6210° 19 kt251002.4
21:53 UTC73.462.6210° 16 kt291001.7
22:20 UTC71.662.6210° 45 kt521004.4+RA
22:35 UTC62.660.8210° 19 kt351004.1TSRA
22:36 UTC62.660.8210° 19 kt351004.1TSRA
22:53 UTC62.660.8210° 11 kt231003.4VCTSRA
23:20 UTC62.660.8220° 10 kt171002.7-RA
23:53 UTC62.660.8240° 6 kt1002.4

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

The radar

The State College radar (KCCX), 47 km away, was scanning. The volume nearest the touchdown began at 22:45 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
22:00 UTCTSTM WND DMGSnow ShoeCentre, PANUMEROUS TREES DOWN IN SNOW SHOE
22:00 UTCTSTM WND DMGSnow ShoeCentre, PASHED DAMAGED AND TREES DOWN.
22:10 UTCTSTM WND DMGStormstownCentre, PAPOWER LINES DOWN ON ROUTE 550
22:19 UTCTSTM WND DMG1 Wnw Pennsylvania FurnHuntingdon, PATREES ON ROAD.
22:19 UTCTSTM WND DMGPark ForestCentre, PATREES DOWN IN WOODYCREST
22:23 UTCTSTM WND DMGPleasant GapCentre, PATREE DOWN.
22:23 UTCTSTM WND DMGState CollegeCentre, PALARGE PINE TREE BLOCKING NORTH ATHERTON STREET
22:27 UTCTSTM WND DMGBoalsburgCentre, PATREE DOWN.
22:27 UTCTSTM WND DMGPine Grove MillsCentre, PALARGE TREE DOWN.
22:30 UTCTSTM WND DMGUniversity ParkCentre, PAPINE TREES BLOCKING BURROWES ROAD AT WARING COMMONS
22:31 UTCTSTM WND DMG1 Nne Lebo VistaLycoming, PATREES AND WIRES DOWN.
22:35 UTCTSTM WND DMGBoalsburgCentre, PANUMEROUS TREES DOWN NEAR MILITARY MUSEUM
22:40 UTCTSTM WND DMG2 Nne HublersburgCentre, PAA SWATH OF DOWNED TREES WAS OBSERVED BEHIND HOMES ALONG SAND RIDGE ROAD AND PONDEROSA ROAD.
22:44 UTCTORNADORebersburgCentre, PAAN EF1 TORNADO WITH PEAK WINDS OF APPROXIMATELY 110 MPH WAS CONFIRMED BY A NWS SURVEY.
22:45 UTCTSTM WND DMGLamarClinton, PATREES DOWN ON HOMES
22:45 UTCTSTM WND DMGLock HavenClinton, PANUMEROUS TREES DOWN
22:46 UTCTSTM WND DMGSpring MillsCentre, PAA SWATH OF DOWNED TREES WAS OBSERVED NEAR SPRING MILLS.
22:49 UTCTSTM WND DMGMackeyvilleClinton, PATREES AND WIRES DOWN.
22:51 UTCTSTM WND DMG1 Nne Lebo VistaLycoming, PATREES AND WIRES DOWN.
22:51 UTCTSTM WND DMGAaronsburgCentre, PALARGE TREE LIMBS AND BRANCHES DOWN.
22:52 UTCTSTM WND DMG1 N MillheimCentre, PAA SWATH OF AT LEAST 50 TREES WAS OBSERVED TO BE SNAPPED OR DOWNED ON A RIDGE ALONG ROUTE 445.
22:52 UTCTSTM WND DMG1 W CoburnCentre, PAA SWATH OF TREES WAS OBSERVED DOWN AND 3 SEPARATE BARNS HAD ROOFS REMOVED.
22:53 UTCTSTM WND DMG1 Ne CoburnCentre, PAAPPROXIMATELY 3 DOZEN TREES WERE DOWNED OR SNAPPED AND A POLE BARN WAS DAMAGED.
22:56 UTCTSTM WND DMGBurnhamMifflin, PANUMEROUS TREES DOWN.
22:56 UTCTSTM WND GST 66Lock HavenClinton, PA66 MPH GUST RECORDED AT LOCK HAVEN PIPER AIRPORT
22:57 UTCTSTM WND DMGJersey ShoreLycoming, PATREES DOWN.
23:00 UTCTSTM WND DMG2 Nw LogantonClinton, PAA LARGE SWATH OF DOWNED TREES APPROXIMATELY A MILE LONG WAS OBSERVED NORTH OF I-80.
23:07 UTCTSTM WND DMGCollomsvilleLycoming, PANUMEROUS TREES DOWN.
23:11 UTCTSTM WND DMG1 Ssw NisbetLycoming, PANUMEROUS TREES DOWN.
23:13 UTCTSTM WND DMG3 Ssw ElimsportLycoming, PATREES DOWN AND SEVERAL SHEETS BARN ROOF TORN OFF.
23:15 UTCTSTM WND GST 85WilliamsportLycoming, PA
23:25 UTCTSTM WND DMGMifflinburgUnion, PANUMEROUS TREES DOWN. TREE ON CAR ON MARKET ST.

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

This ground now

The live radar over the trackEvery 2017 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

The other tornadoes of May 1, 2017

14 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 110:07 AM EDTEF0Chattahoochee, GA0.550$12,000
May 110:24 AM EDTEF0Forsyth, GA2.4150$25,000
May 12:30 PM EDTEF0Butler, PA2.950$20,000
May 12:56 PM EDTEF0Butler, PA0.450$5,000
May 13:09 PM EDTEF0Clarion, PA0.975$15,000
May 13:25 PM EDTEF0Clarion, PA0.5100$10,000
May 13:27 PM EDTEF0Clarion, PA0.875$10,000
May 13:27 PM EDTEF1Forest, PA2.2100$50,000
May 13:35 PM EDTEF1Forest, PA0.8150
May 13:39 PM EDTEF1Forest, PA0.250
May 13:40 PM EDTEF2Forest, PA0.9350
May 13:42 PM EDTEF2Forest, PA1.1175
May 13:54 PM EDTEF0Catawba, NC2.750$10,000
May 14:08 PM EDTEF1Elk, PA1.7200

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.