F0 tornado, Spring Church to Iselin, Pennsylvania, April 28, 2002

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.

Rating

F0

Date

April 28, 2002

Touchdown

3:45 PM EDT (19:45 UTC)

Path length

4.0 miles (6.4 km)

Path width

150 yards (137 m)

Deaths

0

Injuries

0

Property damage

$170,000

Counties

Armstrong and Indiana counties

Touchdown point

40.580, -79.480

Lift-off point

40.570, -79.380

Record number

522

A storm spawning two separate tornadoes passed over southern Armstrong County, continuing eastward into Indiana County. The first tornado, an F0, touched down at approximately 2:45 PM EST just south of the town of Spring Church in Armstrong County. It traveled east about 3 miles before crossing into Indiana County approximately 1 mile east of Maysville at 2:52 PM EST. This tornado continued traveling to the east for another mile, finally dissipating near the community of Iselin at around 2:55 PM EST. The maximum estimated winds with this tornado were about 70 MPH.Damage from this first tornado included numerous trees which were toppled or snapped. A small steeple was toppled, and a swimming pool was destroyed. There were several trees toppled onto houses, and some houses suffered minor wind damage. A garage was damaged, and a house under construction was lifted off the foundation. The same storm produced another stronger tornado, an F2, which touched down in Indiana County approximately 6 miles southwest of the city of Indiana at 3:00 PM EST. This F2 traveled to the east across Center Township for approximately 5 miles, dissipating just south of Indiana at 3:06 PM EST. The estimated maximum winds were around 135 MPH. This F2 tornado produced a swath of damage as it traveled eastward across Indiana County. One house was totally destroyed, and debris from this house was blown downwind. In this same area, a car was turned over and trees were stripped of leaves. An adjacent house exhibited damage from hail or flying projectiles on several sides. The house immediately to the north of the destroyed house lost part of its east-facing roof. There were at least an additional 18 houses damaged (roofs, shingles, siding, etc.). Several garages and barns were either toppled or snapped. A large sign from a hotel was blown down onto a car sales lot. Two cars were crushed and 18 other vehicles were damaged. One moderate injury was reported with this tornado.

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

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

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 Storm Prediction Center had this point in a Moderate Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 16:56 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 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.

The Pittsburgh radar (KPBZ), 67 km away, was scanning. The volume nearest the touchdown began at 19:45 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.

The live radar over the trackEvery 2002 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

37 more were confirmed in the United States that day.

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.