Tornadoes · United States · Pennsylvania · 1998

F1 tornado, Table Rock, Pennsylvania, April 1, 1998

This F1 tornado ran 1.5 miles across Adams County on April 1, 1998, touching down at 12:30 PM EST and reaching 100 yards wide. It killed nobody.

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 mph

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

  2. F173 to 112 mphthis tornado

    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
F1
Date
April 1, 1998
Touchdown
12:30 PM EST (17:30 UTC)
Path length
1.5 miles (2.4 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Adams County
Touchdown point
39.920, -77.220
Lift-off point
39.920, -77.220
Record number
55

What the Weather Service recorded

A small tornado touched down just south of Table Rock north of Route 394, about 5 miles northeast of Gettysburg, around 12:30 pm EST on 4/1/98. The storm moved northeast for 1-1/2 miles, destroying a barn and taking down trees along a 100 yard wide path. A small chicken coop was blown away just north of Route 394 at the beginning of the damage. From there, the storm crossed open fields for 1/2 mile, picked up a horse watering trough and a bench, then blew over a fence. The tornado continued northeast, taking the roof off a barn, blowing in the barn doors on the south side of a barn, and blowing out the north side walls. A small cedar tree had been snapped off at the base and rolled north up a fence line, then hurled northeast about 30 feet. A farmhouse just northwest of the barn was undamaged. A number of trees were damaged as the tornado continued northeast to about 1-1/2 miles northeast of Table Rock. A woman at a home used as a daycare center told of hearing the warning alert on the radio and hurrying the children to the basement shortly before the storm struck.

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.

Issued (UTC)ExpiredProductOffice
16:42 UTC17:45 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. The outlook in force was issued at 10:42 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.

Phillips Aaf/Abe, MD (KAPG), 12:00Z

5.5 hours before the tornado, 108 km from the path. April 1, 1998.

Skew-T log-pSkew-T log-p diagram, Phillips Aaf/Abe, MD at 12:00Z on 1998-04-01Temperature 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 -5967, lifted condensation level 1059 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, Phillips Aaf/Abe, MD at 12:00Z on 1998-04-01The 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 179 square meters per square second, 0 to 6 km bulk shear 28 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
-5967 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1059 m above ground
0-6 km bulk shear
28 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
179 m²/s²
0-3 km storm-relative helicity
141 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

The radar

The Sterling radar (KLWX), 107 km away, was scanning. The volume nearest the touchdown began at 17:29 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 1998 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

The other tornadoes of April 1, 1998

12 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 112:40 PM ESTF0Montour, PA2.01,200
April 12:37 PM ESTF1Chester, PA0.51001$30,000
April 13:45 PM ESTF0Wayne, NC0.550$30,000
April 13:50 PM ESTF1Lenoir, NC1.050$30,000
April 13:55 PM ESTF1Lenoir, NC1.5100$350,000
April 14:05 PM ESTF1Lenoir, NC1.5803$90,000
April 14:50 PM ESTF0Lenoir, NC1.050
April 15:15 PM ESTF0Jones, NC0.550
April 15:30 PM ESTF0Craven, NC0.550
April 15:44 PM ESTF0Craven, NC0.550
April 17:00 PM ESTF3Hanover, VA5.04002$800,000
April 17:06 PM ESTF2Caroline, VA4.02001$200,000

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.