Tornadoes · United States · Pennsylvania · 2003
F3 tornado, Ellisburg, Pennsylvania, July 21, 2003
This F3 tornado ran 2.5 miles across Potter County on July 21, 2003, touching down at 4:00 PM EDT and reaching 200 yards wide. It killed nobody, and did $200,000 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.
F040 to 72 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
F3158 to 206 mphthis tornado
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- F3
- Date
- July 21, 2003
- Touchdown
- 4:00 PM EDT (20:00 UTC)
- Path length
- 2.5 miles (4.0 km)
- Path width
- 200 yards (183 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $200,000
- County
- Potter County
- Touchdown point
- 41.920, -77.930
- Lift-off point
- 41.920, -77.930
- Record number
- 503
What the Weather Service recorded
A team from the National Weather Service office in State College surveyed damage and interviewed residents and emergency management officials in Potter county. The team determined that an F3 tornado touched down in Potter county around 4:00 pm Monday July 21 2003. The tornado first touched down about 2 miles southwest of the town of Ellisburg...where it downed hundreds of trees. The tornado continued to the northeast...where it hit the Smoker Farm. The barn and house were completely destroyed...and one of three silos was tipped over. A second home on Smoker Road was also extensively damaged and is uninhabitable. In addition...a car was picked up and thrown 600 yards. A farm tractor was lifted into the trees. The tornado path was 2 1/2 miles long...while the width was about 200 yards. Based on the damage...the tornado was mainly an F2...but rated as a weak F3 at its peak with winds of 160 mph. There were two injuries, but no deaths.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
9 minutes of warning. NWS CTP issued a tornado warning for this county at 19:51 UTC, 9 minutes before the tornado touched down, in force until 20:15 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 19:24 UTC | 20:45 UTC | Severe Thunderstorm Warning | CTP |
| 19:51 UTC | 20:15 UTC | Tornado Warning | CTP |
| 03:19 UTC | 03:45 UTC | Severe Thunderstorm Warning | CTP |
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 19:22 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.
Buffalo Intl Airport, NY (KBUF), 12:00Z
8.0 hours before the tornado, 129 km from the path. July 21, 2003.
- Mixed-layer CAPE
- 348 J/kg
- Mixed-layer CIN
- -9 J/kg
- Surface CAPE
- 756 J/kg
- Mixed-layer LCL
- 653 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 58 m²/s²
- 0-3 km storm-relative helicity
- 105 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.8
- 0-3 km lapse rate
- 6.1 K/km
Buffalo Intl Airport, NY (KBUF), 00:00Z
4.0 hours after it, 129 km from the path. July 22, 2003.
- Mixed-layer CAPE
- 49 J/kg
- Mixed-layer CIN
- -12 J/kg
- Surface CAPE
- 394 J/kg
- Mixed-layer LCL
- 615 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km bulk shear
- 11 kt
- 0-1 km storm-relative helicity
- 32 m²/s²
- 0-3 km storm-relative helicity
- 44 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.1 K/km
The radar
The State College radar (KCCX), 111 km away, was scanning. The volume nearest the touchdown began at 20:02 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.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| July 21 | 3:15 AM EST | F0 | Cass, IN | 2.0 | 100 | |||
| July 21 | 4:00 AM EST | F0 | Tippecanoe, IN | 0.5 | 50 | |||
| July 21 | 5:00 AM EST | F0 | Boone, IN | 2.5 | 50 | $10,000 | ||
| July 21 | 1:45 PM EDT | F1 | Mahoning, OH | 8.0 | 75 | $1.0 million | ||
| July 21 | 2:25 PM EDT | F0 | Mercer, PA | 3.0 | 80 | $10,000 | ||
| July 21 | 3:15 PM EDT | F1 | McKean, PA | 5.5 | 600 | $46 million | ||
| July 21 | 5:00 PM EDT | F1 | Juniata, PA | 3.0 | 200 | $20,000 | ||
| July 21 | 5:30 PM EDT | F1 | Lycoming, PA | 5.0 | 900 | $10,000 | ||
| July 21 | 5:38 PM EST | F0 | Daviess, IN | 0.5 | 50 | $10,000 | ||
| July 21 | 7:20 PM EDT | F1 | Sullivan, NY | 3.0 | 200 | $100,000 | ||
| July 21 | 8:14 PM EDT | F1 | Greene, NY | 0.5 | 50 | $30,000 | ||
| July 21 | 8:23 PM EDT | F2 | Greene, NY | 1.5 | 150 | 7 | $1.0 million | |
| July 21 | 8:24 PM EDT | F1 | Greene, NY | 0.5 | 50 | $10,000 | ||
| July 21 | 8:30 PM EDT | F1 | Greene, NY | 0.5 | 150 | $100,000 | ||
| July 21 | 8:32 PM EDT | F1 | Columbia, NY | 1.8 | 90 | $150,000 | ||
| July 21 | 8:35 PM EDT | F0 | Columbia, NY | 0.4 | 125 | $10,000 | ||
| July 21 | 8:38 PM EDT | F0 | Columbia, NY | 0.5 | 60 | $10,000 | ||
| July 21 | 8:40 PM EDT | F0 | Columbia, NY | 0.5 | 60 | $10,000 | ||
| July 21 | 8:40 PM EDT | F0 | Columbia, NY | 4.0 | 50 | $20,000 | ||
| July 21 | 8:43 PM EDT | F2 | Columbia, NY | 1.3 | 50 | 1 | $200,000 | |
| July 21 | 8:45 PM EDT | F1 | Rensselaer, NY | 4.8 | 90 | $50,000 | ||
| July 21 | 6:53 PM MDT | F0 | Keith, NE | 0.1 | 10 | |||
| July 21 | 9:20 PM EDT | F1 | Bennington, VT | 25.0 | 150 | $150,000 | ||
| July 21 | 8:30 PM CDT | F0 | Cheyenne, KS | 0.2 | 25 | |||
| July 21 | 9:56 PM EDT | F1 | Windham, VT | 2.0 | 100 | $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.