Tornadoes · United States · Wisconsin · 2009

EF0 tornado, Milton Jct, Wisconsin, June 23, 2009

This EF0 tornado ran 0.8 miles across Rock County on June 23, 2009, touching down at 8:09 PM CDT and reaching 30 yards wide. It killed nobody, and did $8,000 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 23, 2009
Touchdown
8:09 PM CDT (01:09 UTC)
Lifted
8:11 PM CDT (01:11 UTC)
On the ground
2 minutes
Path length
0.8 miles (1.4 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
Property damage
$8,000
County
Rock County
Touchdown point
42.799, -88.984
Lift-off point
42.795, -88.968
Record number
0906231909-01

What the Weather Service recorded

A single isolated cell developed quickly in the Edgerton area of north-central Rock County, moved east-southeast, and produced a weak landspout-type tornado and wind damage northwest of the Milton area.

An isolated thunderstorm cell quickly developed and spun up a weak landspout-type tornado that was spotted by the Janesville airport observer, trained spotters and the public. It began over the southwest part of Clear Lake and moved east-southeast and ended just east of STH 59. A screen porch was ripped off a mobile home trailer and some trees just south and southeast of Clear Lake were uprooted or damaged. The estimated max wind speeds of were 70-75 mph. Starting and ending location of 42.79879/-88.98358 and 42.79540/-88.96750. The compass bearing was 117 degrees. The average path width was about 15 yds. DI#3, DOD2.

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

The warnings

9 minutes of warning. NWS MKX issued a tornado warning for this county at 01:00 UTC, 9 minutes before the tornado touched down, in force until 01:30 UTC.

Issued (UTC)ExpiredProductOffice
17:00 UTC00:00 UTCHeat AdvisoryMKX
01:00 UTC01:30 UTCTornado WarningMKX
17:00 UTC00:00 UTCHeat AdvisoryMKX

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 00:48 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), 00:00Z

1.2 hours before the tornado, 181 km from the path. June 24, 2009.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2009-06-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1824 joules per kilogram, CIN -17, lifted condensation level 1743 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, Davenport, at 00:00Z on 2009-06-24The 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 -12 square meters per square second, 0 to 6 km bulk shear 3 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
1824 J/kg
Mixed-layer CIN
-17 J/kg
Surface CAPE
3755 J/kg
Mixed-layer LCL
1743 m above ground
0-6 km bulk shear
3 kt
0-1 km bulk shear
4 kt
0-1 km storm-relative helicity
-12 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.4 K/km

Open this sounding in Storm Lab

Davenport, (KDVN), 12:00Z

10.8 hours after it, 181 km from the path. June 24, 2009.

Skew-T log-pSkew-T log-p diagram, Davenport, at 12:00Z on 2009-06-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 3 joules per kilogram, CIN -382, lifted condensation level 1630 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, Davenport, at 12:00Z on 2009-06-24The 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 17 square meters per square second, 0 to 6 km bulk shear 15 knots.1939Sfc1 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
3 J/kg
Mixed-layer CIN
-382 J/kg
Surface CAPE
42 J/kg
Mixed-layer LCL
1630 m above ground
0-6 km bulk shear
15 kt
0-1 km bulk shear
9 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
40 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

The radar

The Milwaukee radar (KMKX), 39 km away, was scanning. The volume nearest the touchdown began at 01:10 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
00:55 UTCFUNNEL CLOUD3 Se EdgertonRock, WIAIRPLANE PILOT SPOTTED FUNNEL CLOUD ALMOST TOUCHING THE GROUND NEAR EDGERTON.
01:10 UTCTORNADO 05 Se EdgertonRock, WIA STORM SURVEY DETERMINED AN EF0 TORNADO TOUCHED DOWN NEAR CLEAR LAKE...OR 5 SE OF EDGERTON. A SCREEN WAS FLIPPED OVER A TRAILER. MINIMAL TREE AND POWER LINE DAMAGE WAS ALSO OBSERVED MAINLY TO THE SOUTHEAST OF THE LAKE.
01:10 UTCTORNADO5 Se EdgertonRock, WITORNADO REPORTED ON THE GROUND.

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

This ground now

The live radar over the trackEvery 2009 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

The other tornadoes of June 23, 2009

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 234:45 PM EDTEF0Citrus, FL0.550$250,000
June 235:15 PM EDTEF0Franklin, FL0.625$5,000
June 234:58 PM MDTEF0Elbert, CO0.150
June 237:07 PM CDTEF0Logan, NE3.020
June 238:54 PM CDTEF0Custer, NE0.130
June 238:07 PM MDTEF0Logan, CO0.150
June 2312:25 AM EDTEF1Sarasota, FL0.6100$350,000

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.