Tornadoes · United States · Pennsylvania · 2021

EF0 tornado, Nanty Glo, Pennsylvania, July 29, 2021

This EF0 tornado ran 0.1 miles across Cambria County on July 29, 2021, touching down at 6:10 PM EDT and reaching 15 yards wide. It killed nobody.

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
July 29, 2021
Touchdown
6:10 PM EDT (22:10 UTC)
Lifted
6:11 PM EDT (22:11 UTC)
On the ground
1 minutes
Path length
0.1 miles (0.1 km)
Path width
15 yards (14 m)
Deaths
0
Injuries
0
County
Cambria County
Touchdown point
40.480, -78.838
Lift-off point
40.480, -78.837
Record number
2107291610-01

The damage survey

2 damage points were recorded along this path by NWS CTP, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 70 mph.

  • Portable toilet and small set of bleachers displaced.

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

What the Weather Service recorded

An EF-0 tornado touched down near Nanty Glo during the early evening of July 29, 2021. The tornado had maximum winds near 70 mph, a path length of 350 feet and a maximum path width of 15 yards.

An EF-0 tornado touched down near Nanty Glo during the early evening of July 29, 2021. The tornado had maximum winds near 70 mph, a path length of 350 feet and a maximum path width of 15 yards. Touch down occurred on the western side of the Blacklick Valley High School football field and the tornado moved southeastward across the field before lifting on the eastern side of the football field. The tornado displaced small bleachers and knocked over a portable toilet. A few trees around the football field were snapped as well.

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 severe thunderstorm watch, issued at 19:15 UTC and running to 00:43 UTC.

Issued (UTC)ExpiredProductOffice
17:50 UTC18:15 UTCSevere Thunderstorm WarningCTP
19:15 UTC00:43 UTCSevere Thunderstorm WatchCTP
22:24 UTC22:36 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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:53 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 (KPIT), 12:00Z

10.2 hours before the tornado, 107 km from the path. July 29, 2021.

Skew-T log-pSkew-T log-p diagram, Pittsburgh, PA at 12:00Z on 2021-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 136 joules per kilogram, CIN -76, lifted condensation level 1222 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 2021-07-29The 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 175 square meters per square second, 0 to 6 km bulk shear 43 knots.19395878Sfc1 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
136 J/kg
Mixed-layer CIN
-76 J/kg
Surface CAPE
73 J/kg
Mixed-layer LCL
1222 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
175 m²/s²
0-3 km storm-relative helicity
213 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
4.2 K/km

Open this sounding in Storm Lab

Pittsburgh, PA (KPIT), 00:00Z

1.8 hours after it, 107 km from the path. July 30, 2021.

Skew-T log-pSkew-T log-p diagram, Pittsburgh, PA at 00:00Z on 2021-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1003 joules per kilogram, CIN -32, lifted condensation level 915 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 2021-07-30The 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 97 square meters per square second, 0 to 6 km bulk shear 40 knots.19395878Sfc1 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
1003 J/kg
Mixed-layer CIN
-32 J/kg
Surface CAPE
2613 J/kg
Mixed-layer LCL
915 m above ground
0-6 km bulk shear
40 kt
0-1 km bulk shear
23 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.4
Supercell composite
4.9
0-3 km lapse rate
5.8 K/km

Open this sounding in Storm Lab

The radar

The State College radar (KCCX), 86 km away, was scanning. The volume nearest the touchdown began at 22:08 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
21:17 UTCTSTM WND DMG2 Sw IdealIndiana, PABARN ROOF BLOWN OFF STRUCTURE; TIME ESTIMATE BASED ON RADAR
21:20 UTCTORNADO2 Wsw IdealIndiana, PANWS SURVEY TEAM OBSERVED EF0 TORNADO DAMAGE NEAR GEESEY ROAD, WHERE CORN FIELDS WERE DISRUPTED AND FARM OUTBUILDINGS WERE DAMAGED. TIME ESTIMATE BASED ON RADAR.
21:30 UTCTSTM WND DMG1 N DilltownIndiana, PAUTILITY LINES DOWN ALONG DILLTOWN HEIGHTS ROAD IN BUFFINGTON TOWNSHIP
22:10 UTCTORNADO1 Nnw Nanty-GloCambria, PAA TORNADO OCCURRED ON THE EVENING OF JULY 29TH, 2021 NEAR NANTY-GLO, CAMBRIA COUNTY, PENNSYLVANIA. THE TORNADO DEVELOPED ON THE WESTERN SIDE OF THE BLACKLICK VALLEY HIGH SCHOOL FOOTBALL FIELD AND MOVED SOUTHEAST ACROSS T
22:12 UTCTSTM WND DMG1 N Nanty-GloCambria, PABLEACHERS AND A PORTABLE TOILET WHERE KNOCKED OVER AT BLACKLICK VALLEY HIGH SCHOOL.

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

This ground now

The live radar over the trackEvery 2021 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

The other tornadoes of July 29, 2021

36 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 291:05 AM CDTEF0Jefferson, WI6.0100
July 291:07 AM CDTEF0Jefferson, WI3.625
July 291:07 AM CDTEF1Jefferson, WI7.7200
July 291:23 AM CDTEF1Jefferson, WI4.7150
July 291:26 AM CDTEF1Waukesha, WI1.075
July 291:32 AM CDTEF0Waukesha, WI2.450
July 291:38 AM CDTEF1Waukesha, WI0.995
July 2912:40 PM EDTEF0Crawford, PA0.675
July 2912:55 PM EDTEF0Venango, PA0.315$15,000
July 291:54 PM EDTEF1Westmoreland, PA4.9100$275,000
July 292:25 PM EDTEF1Somerset, PA0.265
July 294:04 PM EDTEF1Lehigh, PA2.990
July 294:25 PM EDTEF1Lehigh, PA1.175
July 294:50 PM EDTEF2Harrison, OH2.7220$200,000
July 294:59 PM EDTEF2Carroll, OH6.2150$500,000
July 295:07 PM EDTEF0Howard, MD0.350$50,000
July 295:15 PM EDTEF1Jefferson, OH2.2300$250,000
July 295:16 PM EDTEF0Washington, OH0.155$500
July 295:20 PM EDTEF0Indiana, PA0.110$50,000
July 295:20 PM EDTEF0Pickaway, OH0.950$100,000
July 295:34 PM EDTEF0Lebanon, PA0.760
July 295:40 PM EDTEF1Bucks, PA2.770
July 295:45 PM EDTEF1Jefferson, OH2.3300$250,000
July 295:54 PM EDTEF0Essex, NJ0.350$330,000
July 294:59 PM CDTEF2Bucks, PA to NJ6.3400
July 296:00 PM EDTEF1Greene, PA2.8200$100,000
July 295:40 PM CDTEF0Cumberland, IL0.550
July 296:56 PM EDTEF1Mercer, NJ1.6100
July 297:04 PM EDTEF3Bensalem tornado, PA3.4530
July 297:07 PM EDTEF0Philadelphia, PA0.440
July 297:58 PM EDTEF1Shelby, IN2.550$43,000
July 298:04 PM EDTEF0Ocean, NJ0.880
July 298:14 PM EDTEF1Shelby, IN0.750$15,000
July 297:20 PM CDTEF1Crawford, IL0.475
July 298:42 PM EDTEF1Ocean, NJ6.5250
July 299:03 PM EDTEF2Ocean, NJ4.2758

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.