Tornadoes · United States · Pennsylvania · 1999

F1 tornado, Hugos Corners, Pennsylvania, July 1, 1999

This F1 tornado ran 5.0 miles across Sullivan County on July 1, 1999, touching down at 7:30 PM EDT and reaching 200 yards wide. It killed nobody, and did $200,000 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
July 1, 1999
Touchdown
7:30 PM EDT (23:30 UTC)
Path length
5.0 miles (8.0 km)
Path width
200 yards (183 m)
Deaths
0
Injuries
0
Property damage
$200,000
County
Sullivan County
Touchdown point
41.520, -76.670
Lift-off point
41.570, -76.600
Record number
749

What the Weather Service recorded

An F1 tornado touched down in Elkland township about two miles northwest of Lincoln Falls on route 154, then moved northeast through a crossroads near Eldredsville to Hugo corners. Trees were blown down as the storm crossed route 154. Just west of McCarty Ridge Road a group of campers narrowly missed injury when a stand of trees were blown over near their site. The heaviest damage was along McCarty Ridge Road near the town of Eldredsville. A well built older home was lifted just slightly on its foundation. The occupants told of seeing a cloud of dust appear as they watched from their basement. A barn nearby was leveled. The roof flew off a sawmill and landed largely intact about 100 feet northwest of the mill. Several other homes had some structural damage and one had shingles removed from a roof. A travel trailer was overturned and an outdoor shed was destroyed. A couple mobile homes were damaged by debris, but were not moved off their foundations. Tree damage was sporadic along the path with a number of trees down in the Hugo Corners area near the end of the path.

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

The warnings

40 minutes of warning. NWS CTP issued a tornado warning for this county at 22:50 UTC, 40 minutes before the tornado touched down, in force until 23:45 UTC.

Issued (UTC)ExpiredProductOffice
22:50 UTC23:45 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 General Thunderstorms Risk. The outlook in force was issued at 19:58 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.

Buffalo Intl Airport, NY (KBUF), 12:00Z

11.5 hours before the tornado, 229 km from the path. July 1, 1999.

Skew-T log-pSkew-T log-p diagram, Buffalo Intl Airport, NY at 12:00Z on 1999-07-01Temperature 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 -84016, lifted condensation level 1291 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, Buffalo Intl Airport, NY at 12:00Z on 1999-07-01The 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 65 square meters per square second, 0 to 6 km bulk shear 33 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
-84016 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1291 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

Buffalo Intl Airport, NY (KBUF), 00:00Z

0.5 hours after it, 229 km from the path. July 2, 1999.

Skew-T log-pSkew-T log-p diagram, Buffalo Intl Airport, NY at 00:00Z on 1999-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 433 joules per kilogram, CIN -1, lifted condensation level 1706 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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, Buffalo Intl Airport, NY at 00:00Z on 1999-07-02The 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 165 square meters per square second, 0 to 6 km bulk shear 36 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
433 J/kg
Mixed-layer CIN
-1 J/kg
Surface CAPE
995 J/kg
Mixed-layer LCL
1706 m above ground
0-6 km bulk shear
36 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
165 m²/s²
0-3 km storm-relative helicity
244 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.4
0-3 km lapse rate
7.5 K/km

Open this sounding in Storm Lab

The radar

The Binghamton radar (KBGM), 91 km away, was scanning. The volume nearest the touchdown began at 23:27 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 1999 tornado in PennsylvaniaEvery tornado in Pennsylvania since 1950Warnings in force in Pennsylvania nowThe forecast where you are

The other tornadoes of July 1, 1999

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 112:45 PM EDTF0Auglaize, OH0.130$10,000
July 12:00 PM EDTF0Newaygo, MI5.020$10,000
July 15:40 PM EDTF1Wayne, OH7.050$150,000
July 15:55 PM EDTF0Preble, OH0.1100$20,000
July 17:00 PM EDTF0Lycoming, PA0.5200$10,000
July 17:55 PM EDTF0Bradford, PA2.7150$10,000
July 17:42 PM CDTF1Calloway, KY9.0400$100,000

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.