Tornadoes · United States · Wisconsin · 2007

EF0 tornado, Potosi to Tennyson, Wisconsin, June 3, 2007

From Potosi to Tennyson, this EF0 tornado ran 0.2 miles across Grant County on June 3, 2007, touching down at 3:30 PM CDT and reaching 20 yards wide. It killed nobody, and did $1,000 of property damage.

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
June 3, 2007
Touchdown
3:30 PM CDT (20:30 UTC)
Lifted
3:32 PM CDT (20:32 UTC)
On the ground
2 minutes
Path length
0.2 miles (0.3 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
Property damage
$1,000
County
Grant County
Touchdown point
42.680, -90.720
Lift-off point
42.680, -90.720
Record number
0706031430-02

What the Weather Service recorded

Law enforcement officials, storm spotters and the public reported tornadoes touched down briefly in the southern part of Grant County.

A small tornado touched down briefly near Highway 61 and 35 just southeast of Potosi, causing some minor tree and crop damage.

A small tornado touched down briefly in Potosi, causing minor structural damage to the roof of a shed.

A small tornado touched down briefly between Dickeyville and the Tennyson area, but no damage was reported.

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

The warnings

1 minute of warning. NWS ARX issued a tornado warning for this county at 20:29 UTC, 1 minute before the tornado touched down, in force until 21:00 UTC.

Issued (UTC)ExpiredProductOffice
20:29 UTC21:00 UTCTornado WarningARX
20:58 UTC21:30 UTCTornado WarningARX

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 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.

Davenport, (KDVN), 12:00Z

8.5 hours before the tornado, 119 km from the path. June 3, 2007.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2007-06-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 114 joules per kilogram, CIN -53, lifted condensation level 903 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, Davenport, at 12:00Z on 2007-06-03The 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 6 square meters per square second, 0 to 6 km bulk shear 26 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
114 J/kg
Mixed-layer CIN
-53 J/kg
Surface CAPE
364 J/kg
Mixed-layer LCL
903 m above ground
0-6 km bulk shear
26 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
6 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
6.0 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 00:00Z

3.5 hours after it, 119 km from the path. June 4, 2007.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2007-06-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 82 joules per kilogram, CIN -22, lifted condensation level 1137 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, Davenport, at 00:00Z on 2007-06-04The 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 25 square meters per square second, 0 to 6 km bulk shear 12 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
82 J/kg
Mixed-layer CIN
-22 J/kg
Surface CAPE
675 J/kg
Mixed-layer LCL
1137 m above ground
0-6 km bulk shear
12 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
24 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.9 K/km

Open this sounding in Storm Lab

The surface observations

Dubuque (DBQ), 31 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:55 UTC6157240° 8 kt1002.7-RA
19:55 UTC6358300° 8 kt1002-RA
20:55 UTC7060350° 6 kt1001.7
21:55 UTC6959320° 5 kt1001.4

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

The radar

The Quad Cities radar (KDVN), 119 km away, was scanning. The volume nearest the touchdown began at 20:28 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
20:20 UTCTORNADO2 Se PotosiGrant, WIPUBLIC REPORTED THAT A TORNADO CAUSED TREE AND CROP DAMAGE
20:26 UTCTORNADO2 S PotosiGrant, WITORNADO REPORTED NEAR THE INTERSECTION OF HIGHWAY 61 AND 35
20:30 UTCTORNADOPotosiGrant, WITORNADO TOOK A ROOF OFF OF A SHED IN THE VILLAGE OF POTOSI ACROSS FROM THE SCHOOL
20:35 UTCTORNADO2 S TennysonGrant, WIPUBLIC REPORTED THAT A TORNADO DAMAGED TREES ALONG ON LONG BRANCH ROAD
20:59 UTCTORNADO2 W CorneliaGrant, WISHERIFF DEPUTY OBSERVED A TORNADO TOUCH DOWN ON COUNTY ROAD O BETWEEN ELM AND OAK ROADS

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 WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

The other tornadoes of June 3, 2007

12 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 312:47 PM CDTEF0Kankakee, IL0.410
June 32:10 PM CDTEF1Washington, WI0.550$25,000
June 32:40 PM CDTEF0Andrews, TX2.850
June 33:22 PM CDTEF0Grant, WI0.330$800
June 32:30 PM MDTEF0Mora, NM0.310
June 33:40 PM CDTEF0Grant, WI0.330
June 34:36 PM CDTEF0Winkler, TX4.050
June 34:48 PM CDTEF0Ector, TX0.51,320
June 35:18 PM MDTEF0Roosevelt, NM0.310
June 36:38 PM CDTEF0Loving, TX2.050
June 35:43 PM MDTEF0Roosevelt, NM0.310
June 37:11 PM CDTEF0Shawano, WI0.110

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.