Tornadoes · United States · Maine · 2001

F1 tornado, Patten to Oakfield, Maine, July 24, 2001

From Patten to Oakfield, this F1 tornado ran 16.0 miles across Aroostook and Penobscot counties on July 24, 2001, touching down at 8:45 PM EDT and reaching 75 yards wide. It killed nobody and injured 1.

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 24, 2001
Touchdown
8:45 PM EDT (00:45 UTC)
Path length
16.0 miles (25.7 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
1
Counties
Aroostook and Penobscot counties
Touchdown point
46.150, -68.680
Lift-off point
46.100, -68.070
Record number
1031

What the Weather Service recorded

Numerous trees were toppled or broken off along the intermittent path of the tornado. The tornado originated in northern Penobscot county and continued intermittently into southeast Aroostook county where it dissipated. Most of the path was through wooded areas. However...around Oakfield...several buildings received damage to shingles and siding. Windows were blown out of several structures and some signs were toppled. Several cars parked near the Oakfield community center were damaged from flying debris with some car windows blown out. One car was thrown 50 to 75 feet and landed on its roof. 6 cars received some damage...with 4 of the cars receiving major damage. One injury was reported to an occupant of one of the parked cars. In Dyer Brook...a metal garage was torn off its foundation and blown 100 feet into the woods. Along Spaulding Lake numerous trees were toppled or broken off...with some landing on houses and camps.

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
19:42 UTC20:15 UTCSevere Thunderstorm WarningCAR

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 20:15 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.

Caribou, ME (KCAR), 00:00Z

0.8 hours before the tornado, 88 km from the path. July 25, 2001.

Skew-T log-pSkew-T log-p diagram, Caribou, ME at 00:00Z on 2001-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2006 joules per kilogram, CIN -6, lifted condensation level 773 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, Caribou, ME at 00:00Z on 2001-07-25The 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 267 square meters per square second, 0 to 6 km bulk shear 57 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
2006 J/kg
Mixed-layer CIN
-6 J/kg
Surface CAPE
2570 J/kg
Mixed-layer LCL
773 m above ground
0-6 km bulk shear
57 kt
0-1 km bulk shear
33 kt
0-1 km storm-relative helicity
267 m²/s²
0-3 km storm-relative helicity
273 m²/s²
Significant tornado parameter
3.6
Supercell composite
13.8
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

Caribou, ME (KCAR), 12:00Z

11.2 hours after it, 88 km from the path. July 25, 2001.

Skew-T log-pSkew-T log-p diagram, Caribou, ME at 12:00Z on 2001-07-25Temperature 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 -97222, lifted condensation level 1134 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Caribou, ME at 12:00Z on 2001-07-25The 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 -20 square meters per square second, 0 to 6 km bulk shear 58 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
0 J/kg
Mixed-layer CIN
-97222 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1134 m above ground
0-6 km bulk shear
58 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
49 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
3.7 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 2001 tornado in MaineEvery tornado in Maine since 1950Warnings in force in Maine nowThe forecast where you are

The other tornadoes of July 24, 2001

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 243:35 PM CDTF0Okaloosa, FL0.250$10,000
July 244:36 PM CDTF0Polk, IA0.225

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.