Tornadoes · United States · Minnesota · 2017

EF0 tornado, Belgrade to Greenwald, Minnesota, September 19, 2017

From Belgrade to Greenwald, this EF0 tornado ran 1.2 miles across Stearns County on September 19, 2017, touching down at 12:48 AM CDT and reaching 330 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 19, 2017
Touchdown
12:48 AM CDT (05:48 UTC)
Lifted
12:49 AM CDT (05:49 UTC)
On the ground
1 minutes
Path length
1.2 miles (1.9 km)
Path width
330 yards (302 m)
Deaths
0
Injuries
0
County
Stearns County
Touchdown point
45.453, -95.009
Lift-off point
45.459, -94.987
Record number
1709192348-01

The damage survey

56 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.

  • downburst damage after tornado dissipated. Note damage pattern spread out after dissipation.
  • Poles four feet deep into ground were pulled out as building was blown to the nne. Appears to be downburst damage after tornado dissipated. Note damage pattern spread out after dissipation.
  • end of the significant downburst damage. Drone footage indicated the damage ended about here.
  • few trees down from downburst associated with dissipated tornado.

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

A strong and potent upper level disturbance, combined with a cold front sweeping across the eastern Dakotas, fired a line of severe thunderstorms that moved eastward into western Minnesota toward midnight. This line of storms continued to progress east-northeast across southern and central Minnesota, which produced fast-moving tornadoes, severe measured wind gusts, and hail as large as tennis balls. This line slowly weakened as it moved into far eastern Minnesota, with general, non-severe thunderstorms as the line progressed into west central Wisconsin after 3 am.

A tornado knocked down several dozen trees, with some landing on cars and sheds. One tree landed on a mobile home. The tornado also destroyed a storage building (the building had been moved from another location and was still in the process of being made ready for business when the tornado came and blew it across the road).

A tornado touched down on the edge of a corn field and moved east-northeast, missing the city of Elrosa by less than a mile. However, it hit several farms, including one where several metal sheds were destroyed. The tornado also knocked down or uprooted many trees and also severely damaged crops, especially corn that was ready for harvest.

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.

The county was under a severe thunderstorm watch, issued at 03:36 UTC and running to 07:27 UTC.

Issued (UTC)ExpiredProductOffice
03:36 UTC07:27 UTCSevere Thunderstorm WatchMPX
05:42 UTC06:15 UTCSevere Thunderstorm WarningMPX
06:11 UTC07:00 UTCSevere Thunderstorm WarningMPX
06:37 UTC07:15 UTCSevere Thunderstorm 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 01:00 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), 00:00Z

5.8 hours before the tornado, 129 km from the path. September 20, 2017.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2017-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 246 joules per kilogram, CIN -155, lifted condensation level 1179 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 2017-09-20The 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 274 square meters per square second, 0 to 6 km bulk shear 42 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
246 J/kg
Mixed-layer CIN
-155 J/kg
Surface CAPE
855 J/kg
Mixed-layer LCL
1179 m above ground
0-6 km bulk shear
42 kt
0-1 km bulk shear
34 kt
0-1 km storm-relative helicity
274 m²/s²
0-3 km storm-relative helicity
454 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.2
0-3 km lapse rate
5.8 K/km

Open this sounding in Storm Lab

Minneapolis, MN (KMPX), 12:00Z

6.2 hours after it, 129 km from the path. September 20, 2017.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 2017-09-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 64 joules per kilogram, CIN -400, lifted condensation level 1019 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 2017-09-20The 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 120 square meters per square second, 0 to 6 km bulk shear 68 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
64 J/kg
Mixed-layer CIN
-400 J/kg
Surface CAPE
88 J/kg
Mixed-layer LCL
1019 m above ground
0-6 km bulk shear
68 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
120 m²/s²
0-3 km storm-relative helicity
129 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

The surface observations

Paynesville (PEX), 22 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
03:53 UTC71.664130° 12 kt171001.4
04:13 UTC71.664.2140° 15 kt201001.4
04:33 UTC71.664.4140° 11 kt191001.7
04:53 UTC71.664.4130° 15 kt231000.3
05:13 UTC71.664.6130° 15 kt201000
05:33 UTC6965.5120° 15 kt24999.3TSRA
05:53 UTC69.365.8140° 14 kt20999.3VCTS
06:13 UTC6460290° 12 kt351003+VCTSRA
06:33 UTC6160.3190° 10 kt141002.7+TSRA
06:53 UTC6261180° 5 kt1002.4-TSRA
07:13 UTC6261.2180° 4 kt1002-VCTSRA
07:33 UTC62.461.7150° 3 kt1002VCTSRA

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

The radar

The Minneapolis radar (KMPX), 131 km away, was scanning. The volume nearest the touchdown began at 05:48 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
05:22 UTCTSTM WND DMG9 Wnw SunburgSwift, MNTREE DAMAGE REPORTED ON THE NORTHWESTERLY SIDE OF CAMP LAKE. A TURKEY BARN'S ROOF AT JENNIE-O INDIAN HILLS FARM WAS TAKEN SOUTHWEST OF CAMP LAKE. BARNS DOWN AND ROOFS OFF ON THE NORTHEAST SIDE OF CAMP LAKE.
05:30 UTCHAIL 1.2510 Wnw SunburgSwift, MNIN SWIFT FALLS ON CR 31.
05:33 UTCTSTM WND DMG5 Wsw SunburgSwift, MNGRAIN BINS AND SHEDS DAMAGED. POSSIBLE TORNADO.
05:40 UTCTSTM WND DMG7 Wsw BrootenPope, MNLARGE TREE DOWN ON HWY 104 ABOUT 2 MILES SOUTH OF CO RD 8 INTERSECTION. REPORTED VIA TWITTER. TIME ESTIMATED.
05:48 UTCTSTM WND DMGBelgradeStearns, MNNUMEROUS LARGE TREES AND POWER LINES DOWN THROUGHOUT THE CITY OF BELGRADE.
06:15 UTCTSTM WND DMGMelroseStearns, MNTREES DOWN AND BUILDING DAMAGE. REPORTS FROM PUBLIC VIA FACEBOOK INCLUDE PHOTOS OF DAMAGE. TIME IS ESTIMATED.
06:16 UTCTSTM WND DMG7 Nw CosmosKandiyohi, MN6 DIAMETER TREE LIMB SNAPPED & WAS BLOCKING ROAD.
06:20 UTCTSTM WND DMG3 Nw BurtrumTodd, MNBOAT AND ATTACHED DOCK ON LONG LAKE DETACHED FROM SHORELINE AND WAS BLOWN INTO ANOTHER DOCK. SEVERAL TREES DOWN ON PROPERTIES ALONG NE SHORELINE. DAMAGE TO ROOF OF HOME. PUBLIC BOAT DOCK BLOCKED BY DOWNED TREES. TIME EST
06:20 UTCHAIL 0.88AvonStearns, MNHAIL WAS DIME TO ALMOST QUARTER SIZE. TIME WAS ESTIMATED. REPORTED VIA FACEBOOK.
06:21 UTCHAIL 12 Sw BowlusMorrison, MN
06:56 UTCHAIL 0.881 Ssw Waite ParkStearns, MN

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

This ground now

The live radar over the trackEvery 2017 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

The other tornadoes of September 19, 2017

11 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
September 191:07 PM PDTEF1Linn, OR0.7167$240,000
September 194:41 PM CDTEF1Barnes, ND3.7200$30,000
September 197:46 PM CDTEF1Spink, SD2.8155
September 197:50 PM CDTEF1Norman, MN4.6100$52,000
September 198:55 PM CDTEF0Clark, SD0.110
September 199:26 PM CDTEF0Clark, SD0.110
September 1912:18 AM CDTEF0Chippewa, MN2.1100
September 1912:22 AM CDTEF1Chippewa, MN0.180
September 1912:28 AM CDTEF1Swift, MN12.6550$1.6 million
September 1912:32 AM CDTEF1Pope, MN9.2880$1.3 million
September 1912:49 AM CDTEF1Stearns, MN8.2360

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.