Tornadoes · United States · Minnesota · 2019

EF0 tornado, Coin, Minnesota, September 21, 2019

This EF0 tornado ran 1.2 miles across Kanabec County on September 21, 2019, touching down at 5:01 PM CDT and reaching 80 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
September 21, 2019
Touchdown
5:01 PM CDT (22:01 UTC)
Lifted
5:04 PM CDT (22:04 UTC)
On the ground
3 minutes
Path length
1.2 miles (2.0 km)
Path width
80 yards (73 m)
Deaths
0
Injuries
0
Crop damage
$10,000
County
Kanabec County
Touchdown point
45.752, -93.311
Lift-off point
45.762, -93.290
Record number
1909211601-01

The damage survey

3 damage points were recorded along this path by NWS MPX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 85 mph.

  • Numerous large branches down 13 days later. Few trees still down. Damage to fences.
  • Bean damage was on both sides of road. Much damage was to the se, but some damage showed a convergent pattern. A storm chaser measured 110 mph on the next road east of here, but that is not deemed a correct speed due to the lack of tree or crop damage where he was.

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

Two storm chasers filmed a tornado in east central Minnesota, in Kanabec County. Earlier, a funnel cloud was documented northeast of St Cloud.

Two storm chasers documented a tornado that mostly crossed open fields. A NWS storm survey revealed damage to some bean fields as well as about two dozen trees uprooted or broken. No structural damage was noted.

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. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
21:00 UTC21:45 UTCSevere Thunderstorm WarningMPX
21:06 UTC21:27 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 20:00 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

10.0 hours before the tornado, 104 km from the path. September 21, 2019.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2019-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 331 joules per kilogram, CIN -48, lifted condensation level 671 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, Minneapolis, MN at 12:00Z on 2019-09-21The 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 255 square meters per square second, 0 to 6 km bulk shear 44 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
331 J/kg
Mixed-layer CIN
-48 J/kg
Surface CAPE
1124 J/kg
Mixed-layer LCL
671 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
255 m²/s²
0-3 km storm-relative helicity
247 m²/s²
Significant tornado parameter
0.4
Supercell composite
5.6
0-3 km lapse rate
4.9 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 00:00Z

2.0 hours after it, 104 km from the path. September 22, 2019.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2019-09-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1719 joules per kilogram, CIN -24, lifted condensation level 1074 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, Minneapolis, MN at 00:00Z on 2019-09-22The 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 217 square meters per square second, 0 to 6 km bulk shear 43 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
1719 J/kg
Mixed-layer CIN
-24 J/kg
Surface CAPE
3438 J/kg
Mixed-layer LCL
1074 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
217 m²/s²
0-3 km storm-relative helicity
213 m²/s²
Significant tornado parameter
1.7
Supercell composite
14.3
0-3 km lapse rate
6.3 K/km

Open this sounding in Storm Lab

The radar

The Minneapolis radar (KMPX), 103 km away, was scanning. The volume nearest the touchdown began at 22:03 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
21:26 UTCFUNNEL CLOUD5 S FoleyBenton, MNNARROW FUNNEL THAT LASTED TWO MINUTES.
21:36 UTCHAIL 0.252 Ene McgrathAitkin, MNTIME 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 2019 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of September 21, 2019

4 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
September 214:48 PM CDTUnratedChautauqua, KS0.525
September 216:12 PM CDTEF1Elk, KS1.275$5,000
September 216:16 PM CDTUnratedElk, KS0.525
September 2112:53 AM CDTUnratedPolk, IA1.625

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.