Tornadoes · United States · Pennsylvania · 1998

F2 tornado, Bustleton, Pennsylvania, May 31, 1998

This F2 tornado ran 5.6 miles across Philadelphia County on May 31, 1998, touching down at 1:20 AM EDT and reaching 200 yards wide. It killed nobody, and did $1.8 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 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 mphthis tornado

    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
F2
Date
May 31, 1998
Touchdown
1:20 AM EDT (05:20 UTC)
Path length
5.6 miles (9.0 km)
Path width
200 yards (183 m)
Deaths
0
Injuries
0
Property damage
$1.8 million
County
Philadelphia County
Touchdown point
40.120, -75.030
Lift-off point
40.080, -74.950
Record number
593

What the Weather Service recorded

A tornado ripped through Upper and Lower Moreland Townships as well as extreme northeast Philadelphia during the early morning of June 1st. The tornado was rated as an F1 (A weak tornado on the Fujita Scale) in Montgomery County and intensified into an F2 (or strong tornado on the Fujita Scale) within Philadelphia. The worst damage occurred within the unoccupied Byberry Industrial Park as the tornado reached its strongest intensity. Thirty-five commercial buildings were damaged, nine severely. Damage outside of the industrial park was mainly confined to downed trees. About ten homes were damaged by fallen trees. The damage within Philadelphia was discontinuous suggesting the tornado was not on the ground for its entire lifetime across the city. Damage was estimated at $1.8 million dollars. Because the buildings were unoccupied, no injuries occurred.The tornado moved into the city from Lower Moreland Township in the Bustleton/Lumar Park area around 120 a.m. EDT. Trees were split and knocked down. The tornado intensified into a strong one (F2 on the Fujita Scale) as it crossed into the Byberry Industrial Park. The worst damage was done in the area around Byberry Road, McNulty Road, Roosevelt Boulevard and Southampton Road. Five ton air conditioning units were tossed. Of the 35 commercial buildings damaged, nine were severely damaged and declared "imminently dangerous". Slabs of the roof were tossed 200 yards. Some buildings lost entire sides, had buckled steel beams, shattered windows and crushed equipment. The tornado plucked utility poles from the ground. About 20 poles were knocked over. Five teams of tree service personnel were overwhelmed. Damage south of the industrial park became sporadic as the tornado turned toward the southeast. It lifted just before the Bucks County border near Woodhaven Road just to the southeast of the Franklin Mills Mall. Its path length was about 5.6 miles and path width about 200 yards. PECO Energy reported 34,000 customers in Philadelphia lost power. Five thousand still did not have power the evening of the 1st. It was the worst non-winter storm in PECO Energy's 50 year history and the fourth worst overall. According to their lightning detection system, there were 7,000 cloud to ground lightning strikes in their service area as this line of thunderstorms moved through.

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
05:15 UTC05:50 UTCSevere Thunderstorm WarningPHI

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 10:32 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

6.7 hours after it, 118 km from the path. June 1, 1998.

Skew-T log-pSkew-T log-p diagram, Phillips Aaf/Abe, MD at 12:00Z on 1998-06-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 45 joules per kilogram, CIN -96, lifted condensation level 807 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, Phillips Aaf/Abe, MD at 12:00Z on 1998-06-01The 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 -135 square meters per square second, 0 to 6 km bulk shear 39 knots.1939587897117Sfc1 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
45 J/kg
Mixed-layer CIN
-96 J/kg
Surface CAPE
810 J/kg
Mixed-layer LCL
807 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
22 kt
0-1 km storm-relative helicity
-135 m²/s²
0-3 km storm-relative helicity
-44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

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 May 31, 1998

45 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 311:20 AM CDTF0Marathon, WI0.250$10,000
May 312:20 AM CDTF1Calumet, WI1.480$300,000
May 315:30 AM EDTF0Missaukee, MI0.3100
May 315:35 AM EDTF0Antrim, MI0.130
May 315:50 AM EDTF1Kalkaska, MI7.0100
May 315:55 AM EDTF0Crawford, MI0.130
May 316:25 AM EDTF0Genesee, MI0.130$10,000
May 3112:44 PM ESTF0DeKalb, IN0.130
May 311:15 PM ESTF0DeKalb, IN0.130
May 313:04 PM EDTF0Putnam, OH0.130
May 313:22 PM CDTF3Saratoga, NY to VT30.597068$71 million
May 314:37 PM EDTF1Albany, NY3.580$30,000
May 314:45 PM EDTF0Delaware, NY3.080$150,000
May 315:05 PM EDTF1Chautauqua, NY2.0302$70,000
May 315:20 PM EDTF1Lycoming, PA0.5440
May 315:30 PM EDTF3Tioga, NY62.020012$2.5 million
May 315:50 PM EDTF2Chenango, NY1.01,500$500,000
May 316:00 PM EDTF0Chenango, NY0.580$140,000
May 316:03 PM EDTF2Hillsborough, NH0.590$30,000
May 316:25 PM EDTF0Otsego, NY0.730$70,000
May 316:30 PM EDTF3Otsego, NY5.08003$800,000
May 317:00 PM EDTF0Luzerne, PA0.240$50,000
May 317:22 PM EDTF2Rensselaer, NY8.0200$180,000
May 317:25 PM EDTF1Clinton, OH0.3100$20,000
May 317:30 PM EDTF1Elk, PA3.0100
May 317:30 PM EDTF0Elk, PA0.5100
May 318:08 PM EDTF2Pike, PA2.0550$200,000
May 318:10 PM EDTF1Cameron, PA5.050
May 318:20 PM EDTF3Pike, PA20.02002$1.0 million
May 318:20 PM EDTF2Pike, PA3.0200$400,000
May 318:20 PM EDTF0Lackawanna, PA0.330$70,000
May 318:20 PM EDTF0Lackawanna, PA0.1100$100,000
May 318:45 PM EDTF1Lycoming, PA7.080
May 318:50 PM EDTF3Somerset, PA13.0880115$4.0 million
May 318:50 PM EDTF0Wayne, PA0.530$50,000
May 319:00 PM EDTF3Berks, PA8.31207$1.4 million
May 319:02 PM EDTF0Lycoming, PA0.550
May 319:15 PM EDTF0Lycoming, PA0.240
May 319:15 PM EDTF1Wyoming, PA0.550$70,000
May 319:30 PM EDTF1Northwest Hills Planning Region, CT0.330$4,000
May 318:35 PM CDTF2Adair, KY1.0100$300,000
May 319:50 PM EDTF0Pike, PA0.330$40,000
May 3110:48 PM EDTF1Bell, KY1.5300$200,000
May 3112:30 AM EDTF2Lancaster, PA7.0880
May 3112:52 AM EDTF1Chester, PA3.0100$300,000

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.