Tornadoes · United States · Pennsylvania · 2003

F0 tornado, New Lebanon, Pennsylvania, July 21, 2003

This F0 tornado ran 3.0 miles across Mercer County on July 21, 2003, touching down at 2:25 PM EDT and reaching 80 yards wide. It killed nobody, and did $10,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mphthis tornado

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

  2. F173 to 112 mph

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

  3. F2113 to 157 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. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

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

  6. F5261 to 318 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
F0
Date
July 21, 2003
Touchdown
2:25 PM EDT (18:25 UTC)
Path length
3.0 miles (4.8 km)
Path width
80 yards (73 m)
Deaths
0
Injuries
0
Property damage
$10,000
County
Mercer County
Touchdown point
41.400, -80.100
Lift-off point
41.430, -80.050
Record number
513

What the Weather Service recorded

F0 tornado touched down around 2:25 PM EDT, just northeast of Lake Wilhelm and traveled northeast at 35 mph, across the New Lebanon area. Many trees were snapped or toppled. A mobile home park was hard hit with tree damage and minor structural damage. One eye witness, driving along Route 173, saw the tornado and debris, just before it hit the area. Path length 3 miles, maximum damage width 80 yards. Maximum winds about 70 mph.

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

The warnings

43 minutes of warning. NWS PBZ issued a tornado warning for this county at 17:42 UTC, 43 minutes before the tornado touched down, in force until 18:45 UTC.

Issued (UTC)ExpiredProductOffice
09:29 UTC12:30 UTCFlash Flood WarningPBZ
17:21 UTC18:15 UTCSevere Thunderstorm WarningPBZ
17:42 UTC18:45 UTCTornado WarningPBZ
17:47 UTC20:45 UTCFlash Flood WarningPBZ
23:26 UTC00:30 UTCSevere Thunderstorm WarningPBZ
23:30 UTC02:30 UTCFlash Flood WarningPBZ
23:33 UTC00:15 UTCTornado WarningPBZ
00:15 UTC01:15 UTCTornado WarningPBZ
02:27 UTC05:15 UTCFlash Flood 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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 16:25 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

6.4 hours before the tornado, 112 km from the path. July 21, 2003.

Skew-T log-pSkew-T log-p diagram, Pittsburgh, PA at 12:00Z on 2003-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1009 joules per kilogram, CIN -36, lifted condensation level 823 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 2003-07-21The 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 134 square meters per square second, 0 to 6 km bulk shear 27 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
1009 J/kg
Mixed-layer CIN
-36 J/kg
Surface CAPE
368 J/kg
Mixed-layer LCL
823 m above ground
0-6 km bulk shear
27 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
134 m²/s²
0-3 km storm-relative helicity
131 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.2
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Pittsburgh, PA (KPIT), 00:00Z

5.6 hours after it, 112 km from the path. July 22, 2003.

Skew-T log-pSkew-T log-p diagram, Pittsburgh, PA at 00:00Z on 2003-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 171 joules per kilogram, CIN -40, lifted condensation level 1282 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 2003-07-22The 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 150 square meters per square second, 0 to 6 km bulk shear 33 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
171 J/kg
Mixed-layer CIN
-40 J/kg
Surface CAPE
319 J/kg
Mixed-layer LCL
1282 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
150 m²/s²
0-3 km storm-relative helicity
181 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.9
0-3 km lapse rate
6.5 K/km

Open this sounding in Storm Lab

The surface observations

Franklin(Awos) (FKL), 18 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
16:35 UTC6866.2120° 8 kt1008.1
16:55 UTC686880° 5 kt1007.1
17:15 UTC686890° 8 kt1005.8
17:35 UTC69.869.880° 8 kt1004.7
17:55 UTC686880° 8 kt1003.4
18:15 UTC69.868190° 25 kt341003.7
18:35 UTC66.262.6210° 26 kt421002.7
18:55 UTC64.462.6270° 15 kt271006.4
19:15 UTC64.462.6260° 9 kt151007.8
19:35 UTC64.464.4250° 13 kt171008.5
19:55 UTC64.462.6270° 7 kt151009.1
20:15 UTC66.264.4270° 5 kt1009.1

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

The radar

The Pittsburgh radar (KPBZ), 99 km away, was scanning. The volume nearest the touchdown began at 18:25 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.

This ground now

The live radar over the trackEvery 2003 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

The other tornadoes of July 21, 2003

25 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 213:15 AM ESTF0Cass, IN2.0100
July 214:00 AM ESTF0Tippecanoe, IN0.550
July 215:00 AM ESTF0Boone, IN2.550$10,000
July 211:45 PM EDTF1Mahoning, OH8.075$1.0 million
July 213:15 PM EDTF1McKean, PA5.5600$46 million
July 214:00 PM EDTF3Potter, PA2.5200$200,000
July 215:00 PM EDTF1Juniata, PA3.0200$20,000
July 215:30 PM EDTF1Lycoming, PA5.0900$10,000
July 215:38 PM ESTF0Daviess, IN0.550$10,000
July 217:20 PM EDTF1Sullivan, NY3.0200$100,000
July 218:14 PM EDTF1Greene, NY0.550$30,000
July 218:23 PM EDTF2Greene, NY1.51507$1.0 million
July 218:24 PM EDTF1Greene, NY0.550$10,000
July 218:30 PM EDTF1Greene, NY0.5150$100,000
July 218:32 PM EDTF1Columbia, NY1.890$150,000
July 218:35 PM EDTF0Columbia, NY0.4125$10,000
July 218:38 PM EDTF0Columbia, NY0.560$10,000
July 218:40 PM EDTF0Columbia, NY0.560$10,000
July 218:40 PM EDTF0Columbia, NY4.050$20,000
July 218:43 PM EDTF2Columbia, NY1.3501$200,000
July 218:45 PM EDTF1Rensselaer, NY4.890$50,000
July 216:53 PM MDTF0Keith, NE0.110
July 219:20 PM EDTF1Bennington, VT25.0150$150,000
July 218:30 PM CDTF0Cheyenne, KS0.225
July 219:56 PM EDTF1Windham, VT2.0100$10,000

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.