Tornadoes · United States · Pennsylvania · 1990

F1 tornado, York County, Pennsylvania, May 13, 1990

This F1 tornado ran 2.0 miles across York County on May 13, 1990, touching down at 6:10 PM EDT and reaching 40 yards wide. It killed nobody, and did $500,000 to $5 million 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 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
May 13, 1990
Touchdown
6:10 PM EDT (22:10 UTC)
Path length
2.0 miles (3.2 km)
Path width
40 yards (37 m)
Deaths
0
Injuries
0
Property damage
$500,000 to $5 million
County
York County
Touchdown point
40.170, -76.850
Record number
315

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
23:19 UTC00:00 UTCTornado 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 06:52 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.

Washington/Dulle, VA (KIAD), 12:00Z

10.2 hours before the tornado, 144 km from the path. May 13, 1990.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 12:00Z on 1990-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 6 joules per kilogram, CIN -272, lifted condensation level 668 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, Washington/Dulle, VA at 12:00Z on 1990-05-13The 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 235 square meters per square second, 0 to 6 km bulk shear 54 knots.1939587897Sfc1 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
6 J/kg
Mixed-layer CIN
-272 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
668 m above ground
0-6 km bulk shear
54 kt
0-1 km bulk shear
35 kt
0-1 km storm-relative helicity
235 m²/s²
0-3 km storm-relative helicity
315 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.6 K/km

Open this sounding in Storm Lab

Washington/Dulle, VA (KIAD), 00:00Z

1.8 hours after it, 144 km from the path. May 14, 1990.

Skew-T log-pSkew-T log-p diagram, Washington/Dulle, VA at 00:00Z on 1990-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 91 joules per kilogram, CIN -154, lifted condensation level 1361 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, Washington/Dulle, VA at 00:00Z on 1990-05-14The 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 29 square meters per square second, 0 to 6 km bulk shear 38 knots.1939587897Sfc1 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
91 J/kg
Mixed-layer CIN
-154 J/kg
Surface CAPE
174 J/kg
Mixed-layer LCL
1361 m above ground
0-6 km bulk shear
38 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
63 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.8 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 1990 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

The other tornadoes of May 13, 1990

15 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 131:30 PM EDTF1Frederick, MD0.533$50,000 to $500,000
May 132:22 PM EDTF0Northampton, NC0.230$5,000 to $50,000
May 131:18 PM MDTF0Morrill, NE0.110under $50
May 131:23 PM MDTF0Morrill, NE0.110under $50
May 131:23 PM MDTF0Morrill, NE0.110under $50
May 132:20 PM MDTF0Garden, NE0.110under $50
May 134:30 PM EDTF0Kent, MD0.113$50,000 to $500,000
May 133:00 PM MDTF0Cheyenne, NE0.110$500 to $5,000
May 133:55 PM MDTF0Garden, NE0.110under $50
May 134:20 PM MDTF0Converse, WY0.550
May 136:45 PM EDTF0Lancaster, PA4.073$5,000 to $50,000
May 134:50 PM MDTF0Sioux, NE0.110under $50
May 135:12 PM MDTF0Sedgwick, CO0.220$500 to $5,000
May 135:25 PM MDTF0Niobrara, WY0.550
May 137:27 PM CDTF0Cheyenne, KS13.010

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.