Tornadoes · United States · Minnesota · 2024

EF0 tornado, Brownsdale to Grand Meadow, Minnesota, August 5, 2024

From Brownsdale to Grand Meadow, this EF0 tornado ran 1.0 miles across Mower County on August 5, 2024, touching down at 8:18 PM CDT and reaching 30 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 5, 2024
Touchdown
8:18 PM CDT (01:18 UTC)
Lifted
8:20 PM CDT (01:20 UTC)
On the ground
2 minutes
Path length
1.0 miles (1.6 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
Crop damage
$20,000
County
Mower County
Touchdown point
43.680, -92.830
Lift-off point
43.690, -92.820
Record number
2408051918-01

The damage survey

2 damage points were recorded along this path by NWS ARX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 74 mph.

  • Estimated via satellite imagery.
  • Several large branches broken off of trees and a pergola blown off its pavers. No other damage to residence and satellite imagery indicates that the tornado was dissipating at this time.

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

What the Weather Service recorded

During the evening hours on August 5th, a line of severe thunderstorms brought strong winds to portions of southeast Minnesota. Additionally, an embedded supercell thunderstorm would go on to produce two tornadoes in southeast Minnesota.

This short EF-0 tornado occurred mainly in a farm field just north of Interstate 90 and about 7 miles east of Austin, Minnesota. Some tree damage occurred at a farm during the onset of the tornado.

This EF-0 tornado stayed mostly in open fields five miles north of Taopi, Minnesota. Tree and light structural damage was reported at one residence near the end of the tornado's path.

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 01:17 UTC, 1 minute before the tornado touched down, in force until 01:27 UTC.

The county was under a tornado watch, issued at 22:26 UTC and running to 02:19 UTC.

Issued (UTC)ExpiredProductOffice
22:26 UTC02:19 UTCTornado WatchARX
00:31 UTC01:15 UTCSevere Thunderstorm WarningARX
01:11 UTC02:00 UTCSevere Thunderstorm WarningARX
01:17 UTC01:27 UTCTornado WarningARX
01:46 UTC02:08 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:46 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), 00:00Z

1.3 hours before the tornado, 143 km from the path. August 6, 2024.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2024-08-06Temperature 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 -92653, lifted condensation level 807 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Minneapolis, MN at 00:00Z on 2024-08-06The 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 -82 square meters per square second, 0 to 6 km bulk shear 44 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
0 J/kg
Mixed-layer CIN
-92653 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
807 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
-82 m²/s²
0-3 km storm-relative helicity
380 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
2.7 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 12:00Z

10.7 hours after it, 143 km from the path. August 6, 2024.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2024-08-06Temperature 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 -92869, lifted condensation level 931 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Minneapolis, MN at 12:00Z on 2024-08-06The 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 -118 square meters per square second, 0 to 6 km bulk shear 45 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
-92869 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
931 m above ground
0-6 km bulk shear
45 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
-118 m²/s²
0-3 km storm-relative helicity
-78 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
2.5 K/km

Open this sounding in Storm Lab

The surface observations

Austin Municipal (AUM), 9 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:35 UTC78.873.4130° 9 kt161011.2
23:55 UTC78.873.4130° 13 kt171010.2
00:15 UTC78.873.4140° 12 kt171009.8VCTS
00:35 UTC78.873.4140° 12 kt161008.8-VCTSRA
00:55 UTC78.873.4140° 9 kt1009.5-TSDZ
01:15 UTC73.471.6340° 14 kt371011.5+TSRA
01:36 UTC71.671.6350° 12 kt181012.2+TSRA
01:55 UTC66.266.210° 10 kt151012.2VCTSRA
02:15 UTC64.462.620° 12 kt171012.9-RA
02:35 UTC62.662.650° 13 kt201013.5
02:55 UTC62.660.840° 13 kt201013.9
03:15 UTC62.660.860° 18 kt231013.9

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

The radar

The La Crosse radar (KARX), 132 km away, was scanning. The volume nearest the touchdown began at 01:20 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
00:42 UTCTSTM WND GST 581 S Dodge CenterDodge, MN
00:46 UTCTSTM WND DMGBerneDodge, MNTree blown down on County Hwy 24.
00:48 UTCTSTM WND DMGMantorvilleDodge, MNPowerline blown down.
00:50 UTCTORNADO3 Nw EmmonsFreeborn, MNEF-1 began 3 NW Emmons and tracked E 6.6 miles. Trees uprooted or trunks snapped. Some outbuildings were heavily damaged. One silo was lofted toward a tree line.
00:59 UTCTORNADO4 S CongerFreeborn, MNMultiple spotters reporting tornado on the ground.
01:01 UTCTORNADO3 Nw EmmonsFreeborn, MNSeveral downed trees near the area of 145th and 670th north of Emmons. Time estimated from radar.
01:18 UTCTORNADO5 Sse BrownsdaleMower, MNAn EF-0 tornado was confirmed with a path from southwest to northeast for 1 mile, max winds of 75 mph and width of 30 yards with damage mainly in a farm field just north of Interstate 90 about 7 miles east of Austin, MN.
01:19 UTCFLASH FLOODAustinMower, MNStreet flooding.
01:35 UTCRAIN 1.13 Ne RochesterOlmsted, MN
01:43 UTCTORNADO5 N TaopiMower, MNEF-0 tornado with max winds of 70 mph located in open fields. Tornado tracked 2 miles east and was on the ground for about 5 minutes. Located with radar and satellite data, no other damage was reported.
02:03 UTCTSTM WND DMG4 Se DouglasOlmsted, MNA medium sized healthy tree was partially uprooted and many other trees were snapped in half - Report from mPing.

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 MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of August 5, 2024

20 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 512:45 PM EDTEF1Erie, NY1.4300
August 55:26 PM CDTEF1Watonwan, MN2.350
August 56:19 PM CDTEF1Waseca, MN6.1150
August 56:58 PM CDTEF1Waseca, MN1.450
August 57:28 PM CDTEF0Faribault, MN4.850
August 57:50 PM CDTEF1Freeborn, MN6.5150
August 58:07 PM CDTUnratedWorth, IA0.320
August 59:35 PM EDTEF1Charleston, SC2.9300
August 58:43 PM CDTUnratedWorth, IA0.120
August 58:43 PM CDTUnratedWorth, IA0.830
August 58:43 PM CDTEF0Mower, MN2.770$5,000
August 510:08 PM EDTEF1Colleton, SC0.690
August 510:55 PM EDTEF0Charleston, SC1.2150
August 59:57 PM CDTEF0Winneshiek, IA0.330
August 510:11 PM CDTEF0Winneshiek, IA1.080$5,000
August 510:29 PM CDTEF1Allamakee, IA3.850$50,000
August 512:14 AM EDTEF0Charleston, SC3.8200
August 512:41 AM EDTEF0Beaufort, SC0.860
August 512:53 AM EDTEF0Beaufort, SC2.160
August 51:33 AM EDTEF1Charleston, SC0.775

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.