Tornadoes · United States · Maine · 2007

EF0 tornado, Guerette, Maine, July 15, 2007

This EF0 tornado ran 1.0 miles across Aroostook County on July 15, 2007, touching down at 6:08 PM EDT and reaching 150 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. EF065 to 85 mphthis tornado

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. EF186 to 110 mph

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

  3. EF2111 to 135 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. EF3136 to 165 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. EF4166 to 200 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. EF5over 200 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
EF0
Date
July 15, 2007
Touchdown
6:08 PM EDT (22:08 UTC)
Lifted
6:16 PM EDT (22:16 UTC)
On the ground
8 minutes
Path length
1.0 miles (1.6 km)
Path width
150 yards (137 m)
Deaths
0
Injuries
0
County
Aroostook County
Touchdown point
47.202, -68.215
Lift-off point
47.212, -68.200
Record number
0707151608-01

What the Weather Service recorded

A squall line developed across northern Maine in advance of an approaching cold front. One storm on the northern end of the squall line developed supercell characteristics. This supercell eventually produced a tornado...microburst and large hail. Other isolated severe thunderstorms also developed.

The tornado formed near the west shoreline of Long Lake...crossed the southern end of the lake...then moved back over land across the east shoreline of the lake before dissipating. The total path length of the tornado was around 1.0 mile. Hundreds of trees were uprooted or snapped along the track of the tornado with many trees also de-barked (DI 27, DOD 3). Several cabins and cottages received minor damage to roofs and siding due to the combination of winds and falling trees. Based on the damage...the tornado winds were estimated around 65 knots (75 mph). The average path width was 125 yards. A microburst also occurred in conjunction with the tornado producing straight-line winds also estimated around 65 knots (75 mph). The damage to trees and structures was due to a combination of tornadic and straight-line winds.

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
22:04 UTC22:30 UTCSevere Thunderstorm WarningCAR
00:53 UTC02:00 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, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 20:04 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), 12:00Z

10.1 hours before the tornado, 41 km from the path. July 15, 2007.

Skew-T log-pSkew-T log-p diagram, Caribou, ME at 12:00Z on 2007-07-15Temperature 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 -74180, lifted condensation level 914 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 2007-07-15The 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 350 square meters per square second, 0 to 6 km bulk shear 57 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
-74180 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
914 m above ground
0-6 km bulk shear
57 kt
0-1 km bulk shear
39 kt
0-1 km storm-relative helicity
350 m²/s²
0-3 km storm-relative helicity
333 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

Caribou, ME (KCAR), 00:00Z

1.9 hours after it, 41 km from the path. July 16, 2007.

Skew-T log-pSkew-T log-p diagram, Caribou, ME at 00:00Z on 2007-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 37 joules per kilogram, CIN -62, lifted condensation level 1169 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 2007-07-16The 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 71 square meters per square second, 0 to 6 km bulk shear 74 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
37 J/kg
Mixed-layer CIN
-62 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1169 m above ground
0-6 km bulk shear
74 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
81 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

The surface observations

Frenchville (FVE), 12 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:27 UTC6860.8170° 8 kt1006.4
20:36 UTC6860.8170° 9 kt161006.4
20:53 UTC6861180° 8 kt181006.4
21:51 UTC66.260.8190° 5 kt1006.4VCTS -RA
21:53 UTC6761 3 kt1006.4VCTS -RA
22:37 UTC64.459150° 3 kt1006.8
22:53 UTC64590° 0 kt1006.8
23:53 UTC6259140° 3 kt1006.4

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Caribou radar (KCBW), 133 km away, was scanning. The volume nearest the touchdown began at 22:08 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.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
22:05 UTCHAIL 1.51 W GueretteAroostook, ME
22:15 UTCTSTM WND DMG10 Se FrenchvilleAroostook, MEJUST EAST OF LONG LAKE...TREES DOWN ACROSS EAST ROAD, ROOF AND SIDING DAMAGE TO SOME COTTAGES, POSSIBLE TORNADO

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2007 tornado in MaineEvery tornado in Maine since 1950Warnings in force in Maine nowThe forecast where you are

The other tornadoes of July 15, 2007

10 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 152:30 AM CDTEF1Bexar, TX0.550$50,000
July 158:06 AM EDTEF0Dare, NC0.110
July 157:16 PM CDTEF2Cass, ND3.0150$250,000
July 157:25 PM CDTEF1Cass, ND10.0200$500,000
July 157:46 PM CDTEF2Ransom, ND3.0200$1.0 million
July 159:19 PM CDTEF1Cass, ND1.5150$1.0 million
July 159:20 PM CDTEF2Cass, ND8.0250$2.5 million
July 1510:30 PM CDTEF1LaMoure, ND1.080$500,000
July 1510:37 PM CDTEF0Sargent, ND0.225
July 1511:18 PM CDTEF0Brown, SD0.110

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.