Tornadoes · United States · Pennsylvania · 1985

F1 tornado, Monroe County, Pennsylvania, May 31, 1985

This F1 tornado ran 0.2 miles across Monroe County on May 31, 1985, touching down at 12:05 AM EDT and reaching 17 yards wide. It killed nobody, and did $500 to $5,000 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 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 31, 1985
Touchdown
12:05 AM EDT (04:05 UTC)
Path length
0.2 miles (0.3 km)
Path width
17 yards (16 m)
Deaths
0
Injuries
0
Property damage
$500 to $5,000
County
Monroe County
Touchdown point
41.180, -75.430
Record number
363

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.

Atlantic City In, NJ (KACY), 00:00Z

4.1 hours before the tornado, 208 km from the path. June 1, 1985.

Skew-T log-pSkew-T log-p diagram, Atlantic City In, NJ at 00:00Z on 1985-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 106 joules per kilogram, CIN -187, lifted condensation level 577 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Atlantic City In, NJ at 00:00Z on 1985-06-01The 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 109 square meters per square second, 0 to 6 km bulk shear 44 knots.19395878Sfc1 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
106 J/kg
Mixed-layer CIN
-187 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
577 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
206 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1
0-3 km lapse rate
3.8 K/km

Open this sounding in Storm Lab

Atlantic City In, NJ (KACY), 12:00Z

7.9 hours after it, 208 km from the path. June 1, 1985.

Skew-T log-pSkew-T log-p diagram, Atlantic City In, NJ at 12:00Z on 1985-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 820 joules per kilogram, CIN -33, lifted condensation level 832 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Atlantic City In, NJ at 12:00Z on 1985-06-01The 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 -37 square meters per square second, 0 to 6 km bulk shear 39 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
820 J/kg
Mixed-layer CIN
-33 J/kg
Surface CAPE
2651 J/kg
Mixed-layer LCL
832 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
-51 m²/s²
Significant tornado parameter
-0.1
Supercell composite
-2.0
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 1985 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

The other tornadoes of May 31, 1985

29 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 313:59 PM CDTF4Albion tornado, Ohio and Pennsylvania14.04001282$5 million to $50 million
May 315:05 PM EDTF3Trumbull, OH15.044030$500,000 to $5 million
May 315:10 PM EDTF2Crawford, PA4.02001
May 314:17 PM CDTF4Atlantic tornado, Ohio and Pennsylvania56.235016125$5 million to $50 million
May 315:23 PM EDTF3Crawford, PA23.02772
May 314:25 PM CDTF4Corry tornado, Pennsylvania and New York28.0440
May 314:28 PM CDTF2Ashtabula, OH to PA10.022015$500,000 to $5 million
May 316:12 PM EDTF3Crawford, PA8.0427$500,000 to $5 million
May 316:25 PM EDTF3Chautauqua, NY13.017710$500,000 to $5 million
May 315:30 PM CDTF5Niles–Wheatland tornado, Ohio and Pennsylvania47.045018310$50 million to $500 million
May 316:30 PM EDTF4Tionesta tornado, PA29.0800730
May 316:30 PM EDTF1Warren, PA5.0130
May 316:50 PM EDTF2Forest, PA19.0300
May 317:06 PM EDTF1Madison, OH0.550$50,000 to $500,000
May 317:15 PM EDTF3Licking, OH29.0150120$5 million to $50 million
May 317:30 PM EDTF3Warren, PA17.08008
May 317:35 PM EDTF4Moshannon State Forest tornado, PA69.03,330$5 million to $50 million
May 317:35 PM EDTF2Columbiana, OH15.022020$5 million to $50 million
May 317:50 PM EDTF1Muskingum, OH11.0775$500,000 to $5 million
May 317:54 PM EDTF2Venango, PA6.01501
May 317:56 PM EDTF0Venango, PA5.0300
May 318:00 PM EDTF4Kane tornado, PA29.01,000440
May 318:10 PM EDTF3Beaver, PA39.02439120$5 million to $50 million
May 318:45 PM EDTF1Stark, OH0.250$5,000 to $50,000
May 319:05 PM EDTF1Adams, OH2.077$5,000 to $50,000
May 319:25 PM EDTF3Lycoming, PA19.0910660$5 million to $50 million
May 319:53 PM EDTF0Indiana, PA6.027
May 3110:30 PM EDTF1St. Lawrence, NY5.050$50,000 to $500,000
May 3110:45 PM EDTF1Luzerne, PA11.0530$50,000 to $500,000

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.