EF1 tornado, Watertown to Minnetrista, Minnesota, September 2, 2019

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 2, 2019

Touchdown

10:08 PM CDT (03:08 UTC)

Lifted

10:13 PM CDT (03:13 UTC)

On the ground

5 minutes

Path length

3.9 miles (6.2 km)

Path width

210 yards (192 m)

Deaths

0

Injuries

0

Property damage

$275,000

Counties

Carver and Hennepin counties

Touchdown point

44.963, -93.792

Lift-off point

44.952, -93.715

Record number

1909022108-01

20 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.

• wall panel blown to the southwest.

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

A line of strong to severe thunderstorms developed across North Dakota during the afternoon of Monday, September 2nd. This line of storms continued to move southeast across west central, central, and southern Minnesota during the evening. Some parts of the line had bow echo segments and produced a couple of tornadoes. One tornado occurred near Howard Lake, and another east of Watertown, on the western edge of the Twin Cities metro area. There were also numerous reports of straight-line winds up to 70 mph along this bow echo segment, plus several large hail reports. These storms continued to move southeast into portions of west central Wisconsin before weakening.

A NWS Storm Survey determined an EF0 tornado developed east of Watertown near County Road 20, and moved southeast into Hennepin County, north of Timber Creek Golf Course. Most of the damage was consistent with EF0 damage with numerous trees blown down or uprooted along its path. The path length in Carver County was 1.3 miles, with a maximum width of 90 yards. The tornado was also confirmed by the MPX radar in real time given the Tornado Debris Signature sampled by the radar.

This is the continuation of the Carver County tornado that moved into Hennepin County northeast of Timber Creek Golf Course. The storm survey determined an EF1 tornado occurred in Hennepin County where trees, crops, and a few machine sheds or outbuildings were damaged or blown down. ||The path length in Hennepin County was 2.5 miles, making the tornado total path length of 3.87 miles. The maximum width in Hennepin County was 210 yards, with a maximum wind speed of 90 mph. ||This tornado was also confirmed by the MPX radar in real time given the Tornado Debris Signature sampled by the radar.

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

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 23:57 UTC and running to 04:13 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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 01:46 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 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.

Buffalo (CFE), 23 km from the path, in the two hours either side.

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

The Minneapolis radar (KMPX), 19 km away, was scanning. The volume nearest the touchdown began at 03:09 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 2019 tornado in MinnesotaEvery tornado in Minnesota since 1950Warnings in force in Minnesota nowThe forecast where you are

2 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.