EF1 tornado, Morristown to Cannon Falls, Minnesota, September 20, 2018

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   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.

Rating

EF1

Date

September 20, 2018

Touchdown

6:44 PM CDT (23:44 UTC)

Lifted

6:51 PM CDT (23:51 UTC)

On the ground

7 minutes

Path length

7.2 miles (11.5 km)

Path width

300 yards (274 m)

Deaths

0

Injuries

0

Counties

Rice and Goodhue counties

Touchdown point

44.247, -93.131

Lift-off point

44.314, -93.020

Record number

1809201744-02

153 damage points were recorded along this path by NWS MPX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF2. The highest wind the damage implies is 132 mph.

• Doors exposed to wind, lower bou d of DOD7. Pics of footings available.
• Witness states lake water blew west before switching east quickly. some roof peeled back.
• Many trees down at residence. Concentrated damage
• large circulation with possibly multiple vortices.

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

A violent outbreak of significant straight line winds, downburst winds, and multiple tornadoes occurred during the afternoon and early evening across southern Minnesota. ||During the afternoon of Thursday, September 20th, a warm front lifted northward across far southern Minnesota. By the late afternoon, the warm front lied from just south of the Minnesota River, northeast to around the city of Wabasha. ||Several thunderstorms developed in southwest Minnesota, and northwest Iowa. These storms moved into far southern Minnesota and quickly intensified and raced off to the east-northeast along, and north of this warm front. ||Damage reports started to come into the office around 4 PM CST in Martin County, with multiple reports of significant damage from south of Mankato, to Waseca, then northeast through Waterville, Morristown, Owatonna, Faribault, Northfield, Cannon Falls, and Red Wing before moving into west central Wisconsin. ||A long, and several day storm survey indicated at least XX confirmed tornadoes occurred in a widespread area of damaging winds from Martin County, northeast into west central Wisconsin. ||The most destruction part of the storm occurred around Waterville, Morristown, Owatonna, Faribault and Cannon Falls. These cities all reported homes, buildings and warehouses either damaged or destroyed. ||Hundreds of large, mature trees were uprooted or snapped along this path of destruction, including numerous trees up to 4 feet in diameter. In addition to the trees, structural damage was widespread including the Faribault airport where 80 planes were either damaged or destroyed as hangers were blown off their foundation. ||The towns of Waterville and Faribault had the most homes damaged which was associated with EF2 tornado damage. ||Two miles west of the Faribault airport, a resort area on Roberds Lake had upwords of 75 percent of the trees uprooted or blown down on the east side of the lake. Some of the trees landed on homes and split them in half.

A NWS storm survey, plus areal footage of drone and satellite data, concluded that an EF1 tornado started north of Morristown. It moved northeast to the intersection of Cedar Lake Blvd, and Fairbanks Avenue, and continued moving northeast across the southeast part of Roberds Lake. It lifted just north of the Faribault airport after being on the ground for nearly 8.6 miles. ||The damage was consistent with EF1 damage with maximum wind speeds of 95 mph and a width of 440 yards. Damage was significant along this path with the worst damage along the south and east sides of Roberds Lake. Areal footage and pictures concluded that hundred of trees, up to 3 feet in diameter, were uprooted or blown down onto houses on the east side of the lake from this tornado. Many of these large trees landed on homes and nearly split them in half.

A NWS storm survey, plus aerial pictures and satellite imagery, concluded that an EF2 tornado started southwest of the Faribault airport, near the intersection of 195th Street West and Cedar Lake Blvd, and tracked 3.0 miles northeast. It destroyed parts of the Faribault airport before lifting just north of the airport grounds. Numerous hangers were either damaged or destroyed. ||The 125 mph winds were estimated based on a well built hanger destroyed and blown off its foundation. Footings were also ripped from its frame. Local officials estimated that 80 airplanes were damaged or destroyed at the airport. Some of the debris was blown across the highway on the north side of the airport.||There was also damage on the southeast side of the tornado track which was consistent with downburst and inflow winds. These winds were estimated up to 85 mph.

A NWS storm survey, plus areal footage of drone and satellite data, concluded that an EF1 tornado tracked 1.6 miles across the north side of Roberds Lake. Damage was consistent with maximum winds of 95 mph. Most of the damage was associated with large trees uprooted and partial roofs loss.

A NWS storm survey, plus areal footage of drone and satellite data, concluded that an EF1 tornado tracked 9.1 miles from northeast of Medford, near the Rice, Steele County line, then northeast to just north of Highway 60 before lifting in a corn field. ||This tornado tracked mainly through corn and soy bean fields, but several homes, silos and grain bins were damaged, or destroyed along the tornado's path. The damage was consistent with EF1 damage with maximum wind speeds of 105 mph and a width of 500 yards.

A NWS storm survey, plus drone footage, concluded that an EF1 tornado started approximately 2.4 miles north of the city of Faribault, and tracked northeast for 4.6 miles before lifting just east of the Cannon River Wilderness Area. All of the damage was associated with uprooted or blown down large trees along the Cannon River. The maximum wind speeds were 95 mph and a path width of 440 yards.

A NWS storm survey, plus areal footage of drone and satellite data, concluded that an EF1 tornado tracked 5.8 miles from southeast of Ruskin, then northeast to the Goodhue, Rice county line. This tornado tracked mainly through corn and soy bean fields, and occasionally damaging a few sheds and outbuildings. The damage was consistent with EF1 damage with maximum wind speeds of 100 mph and a width of 300 yards.

A NWS storm survey, plus areal footage of drone and satellite data, concluded that an EF1 tornado tracked for 5.8 miles, from near the intersection of 150th Street West, and Bagley Ave, or 2.6 miles north of the Faribault airport, northeast to just south of Dundas. ||This tornado tracked mainly through corn and soy bean fields, and occasionally damaging a power pole. One electrical transmission line was blown down near the end of the tornado track which is consistent of 90 mph wind gusts. The largest path width was 440 yards.

A NWS storm survey, plus areal footage of drone and satellite data, concluded that an EF0 tornado tracked 5.5 miles from the intersection of I-35 and 130th Street West, northeast to the city of Dundas. This tornado started with damage to a billboard on I-35 with uprooted pine trees, then mainly damage to corn and soy bean fields, and it ended with several large trees uprooted in Dundas. The damage was consistent with EF0 damage with maximum wind speeds of 75 mph and a width of 75 yards.

This is the continued tornado track from the Rice County tornado that moved an additional 1.4 miles northeast into Goodhue County. A storm survey, and high resolution satellite imagery, concluded that damage was associated with flattened corn and soy bean fields, and a loss of a silo's roof panel. The damage is consistent with EF1 damage with winds up to 90 mph, and a width of 100 yards.

A NWS storm survey, plus areal footage of drone and satellite data, concluded that an EF1 tornado tracked 4.7 miles from southeast of Owatonna, east-northeast across mainly corn and soy bean fields before moving into Goodhue County, north of Dennison. However, near the intersection of 110th Street East, and Jacobs Ave, a barn that was a restaurant and event venue was destroyed. It was called the Red Barn and was completely blown off its foundation. The damage was consistent with EF1 damage with maximum wind speeds of 105 mph and a width of 550 yards.

A NWS storm survey, plus areal footage of drone and satellite data, concluded that an EF0 tornado tracked east of Kenyon, then northeast for 8.2 miles before lifting west of Zumbrota. This tornado tracked mainly through corn and soy bean fields, and occasionally damaged a few sheds and outbuildings. The damage was consistent with EF0 damage with maximum wind speeds of 75 mph and a width of 250 yards.

This is the continued tornado track from the Rice County tornado that moved an additional 0.6 miles northeast into Goodhue County. A storm survey, and drone footage, concluded that damage was associated with uprooted trees along the Rice, Goodhue county line, with a flattened corn field to the northeast of the uprooted trees. The damage was consistent with EF1 damage with maximum wind speeds of 90 mph and a width of 100 yards.

A NWS storm survey, plus drone footage, concluded that an EF1 tornado tracked 1.9 miles which started 3 miles south of Cannon Falls, crossed over Highway 52, and lifted just south of downtown Cannon Falls. This tornado damaged a warehouse building, numerous large trees, homes, and a cemetery. The damage was consistent with EF1 damage with maximum wind speeds of 95 mph and a width of 440 yards. There was other damage to the north of the tornado track which was consistent with downburst winds.

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

25 minutes of warning. NWS MPX issued a tornado warning for this county at 23:19 UTC, 25 minutes before the tornado touched down, in force until 00:00 UTC.

The county was under a tornado watch, issued at 20:34 UTC and running to 00:47 UTC.

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 Storm Prediction Center had this point in a Enhanced Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:49 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 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.

The Minneapolis radar (KMPX), 74 km away, was scanning. The volume nearest the touchdown began at 23:42 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.

Local storm reports within 60 km of the path, in the three hours either side.

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

The live radar over the trackEvery 2018 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

28 more were confirmed in the United States that day.

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.