Tornadoes · United States · Wisconsin · 2024

EF0 tornado, Saint Croix County, Wisconsin, August 29, 2024

This EF0 tornado ran 1.7 miles across Saint Croix County on August 29, 2024, touching down at 6:30 PM CDT and reaching 50 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
August 29, 2024
Touchdown
6:30 PM CDT (23:30 UTC)
Lifted
6:33 PM CDT (23:33 UTC)
On the ground
3 minutes
Path length
1.7 miles (2.8 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
County
Saint Croix County
Touchdown point
44.925, -92.240
Lift-off point
44.942, -92.215
Record number
2408291730-01

The damage survey

5 damage points were recorded along this path by NWS MPX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

  • Several trees broken at a farmstead.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

The warnings

33 minutes of warning. NWS MPX issued a tornado warning for this county at 22:57 UTC, 33 minutes before the tornado touched down, in force until 23:30 UTC.

The county was under a severe thunderstorm watch, issued at 19:34 UTC and running to 00:48 UTC.

Issued (UTC)ExpiredProductOffice
19:34 UTC00:48 UTCSevere Thunderstorm WatchMPX
22:57 UTC23:30 UTCTornado WarningMPX
23:21 UTC00:00 UTCTornado WarningMPX

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 Enhanced Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:54 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.

Minneapolis, MN (KMPX), 12:00Z

11.5 hours before the tornado, 108 km from the path. August 29, 2024.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2024-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 832 joules per kilogram, CIN -148, lifted condensation level 584 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, Minneapolis, MN at 12:00Z on 2024-08-29The 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 242 square meters per square second, 0 to 6 km bulk shear 28 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
832 J/kg
Mixed-layer CIN
-148 J/kg
Surface CAPE
20 J/kg
Mixed-layer LCL
584 m above ground
0-6 km bulk shear
28 kt
0-1 km bulk shear
22 kt
0-1 km storm-relative helicity
242 m²/s²
0-3 km storm-relative helicity
296 m²/s²
Significant tornado parameter
0.0
Supercell composite
8.9
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 00:00Z

0.5 hours after it, 108 km from the path. August 30, 2024.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2024-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 24 joules per kilogram, CIN -144, lifted condensation level 907 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, Minneapolis, MN at 00:00Z on 2024-08-30The 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 129 square meters per square second, 0 to 6 km bulk shear 40 knots.19395878Sfc1 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
24 J/kg
Mixed-layer CIN
-144 J/kg
Surface CAPE
48 J/kg
Mixed-layer LCL
907 m above ground
0-6 km bulk shear
40 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
129 m²/s²
0-3 km storm-relative helicity
154 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.7 K/km

Open this sounding in Storm Lab

The radar

The Minneapolis radar (KMPX), 106 km away, was scanning. The volume nearest the touchdown began at 23:32 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
22:28 UTCTSTM WND DMGBalsam LakePolk, WICo Dispatch reported trees down in the Village of Balsam Lake.
23:09 UTCTSTM WND DMG5 Se River FallsPierce, WIDelayed report, time estimated from radar. Tree uprooted.
23:10 UTCTORNADO4 Se River FallsPierce, WIMultiple reports of brief tornado touching down south of River Falls that has now lifted or become rain wrapped.
23:13 UTCTSTM WND DMG3 Nnw EllsworthPierce, WIPhotos provided via social media of several trees down in the town of Beldenville. Time estimated via radar. Time estimated via radar.
23:13 UTCTORNADO8 Nw El PasoPierce, WICounty dispatch reported numerous trees and power lines down between River Falls and Spring Valley along Hwy 29 between Co Rd W and 650th St. Time estimated via radar.
23:15 UTCTSTM WND DMG3 Se WoodvilleSt. Croix, WIDelayed report of several large trees snapped and uprooted along CR NN near Wilson. Time estimated from radar.
23:18 UTCRAIN 2.22 W AmeryPolk, WI
23:30 UTCTSTM WND DMG4 N Spring ValleySt. Croix, WIReported via X. Lots of tree damage along CR-nn especially near house #435 both N and S.
23:36 UTCTSTM WND DMG2 S WilsonSt. Croix, WILarge tree down blocking road just south of I-94 near Wilson. Time estimated from radar.
23:37 UTCTSTM WND DMG2 Ssw WilsonSt. Croix, WI2 semi-trailers detached and flipped at truck stop by Kwik Trip. Reported via phone. Time estimated via radar.
23:37 UTCTORNADO2 Sw WilsonSt. Croix, WILaw enforcement reported numerous trees downed in several directions, and a street sign snapped in half near exit 28 along I-94.
23:45 UTCTSTM WND DMG3 Ese KnappDunn, WIRelayed via Emergency Manager. Power lines down in the area near US 12 and CR K. Time estimated from radar.
23:50 UTCFLASH FLOOD1 Wsw AmeryPolk, WI4-5 inches of standing water in the city of Amery reported by Co Dispatch. Time estimated via radar.
23:53 UTCTSTM WND DMG2 Se BoycevilleDunn, WIDebris on roadway near 370th St and 950th Ave southeast of Boyceville. Time estimated from radar.
00:27 UTCTSTM WND DMG2 Ssw Eau ClaireEau Claire, WICo Dispatch reported numerous trees and powerlines down in SW Eau Claire. Time estimated by radar.

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

This ground now

The live radar over the trackEvery 2024 tornado in WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

The other tornadoes of August 29, 2024

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 293:05 PM CDTUnratedDickinson, IA0.825
August 294:17 PM EDTEF1Blair, PA0.8100$8,000
August 293:35 PM CDTEF1Morrison, MN7.550
August 294:26 PM CDTEF1Anoka, MN3.6250
August 294:32 PM CDTEF1Anoka, MN9.6250
August 295:46 PM CDTEF0Dakota, MN to WI7.950
August 296:06 PM CDTEF0Pierce, WI6.750

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.