EF0 tornado, Sweetwater, North Dakota, August 3, 2016

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.

Rating

EF0

Date

August 3, 2016

Touchdown

8:41 PM CDT (01:41 UTC)

Lifted

8:43 PM CDT (01:43 UTC)

On the ground

2 minutes

Path length

0.8 miles (1.3 km)

Path width

40 yards (37 m)

Deaths

0

Injuries

0

County

Ramsey County

Touchdown point

48.200, -98.870

Lift-off point

48.200, -98.870

Record number

1608031941-01

By mid to late afternoon of August 3rd, a cold front had moved into central North Dakota. Ahead of the cold front, a warm front extended out to the east, or along the Canadian border. This put all of eastern North Dakota and the northwest quarter of Minnesota in the warm sector, where afternoon highs reached into the 80s to around 90, with dew point readings well into the 60s. A ribbon of extreme instability pooled from north to south just ahead of the cold front, with a lot of low level twisting evident in the wind field. Thunderstorms flared up in a northeast to southwest line around Rugby, North Dakota, then slowly tracked eastward during the evening. Some of the initial thunderstorms resulted in tornadoes in the Bisbee, North Dakota, area, as well as very large hail. In addition, these storms dropped large amounts of rain in the Bisbee area. As these initial storms moved east, they gradually weakened and became more disorganized. Meanwhile, storms along the southern edge of the line strengthened, gradually affecting the Devils Lake, North Dakota, area. Once again, several tornadoes were reported, with large hail as well. By late evening into the early morning hours of August 4th, the line over Devils Lake joined a line that blew up southwest of Jamestown, North Dakota, to form a continuous line of storms. This line of storms continued to move east, pushing through the central and southern Red River Valley, and into portions of west central Minnesota. By the time it reached west central Minnesota, the storms mainly produced damaging wind gusts.

This was the first of two tornadoes viewed and photographed by multiple storm chasers in the Sweetwater Lake area, in southern Freshwater and Morris townships. This tornado tracked over open fields and marshland. Peak winds were estimated at 75 mph.

This was the second of two tornadoes viewed and photographed by multiple storm chasers in the Sweetwater Lake area. This tornado tracked to the east-southeast over open fields and marshland. Peak winds were estimated at 75 mph.

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

22 minutes of warning. NWS FGF issued a tornado warning for this county at 01:19 UTC, 22 minutes before the tornado touched down, in force until 02:00 UTC.

The county was under a tornado watch, issued at 20:42 UTC and running to 02:53 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 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 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 Fargo/Grand Forks radar (KMVX), 137 km away, was scanning. The volume nearest the touchdown began at 01:44 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 2016 tornado in North DakotaEvery tornado in North Dakota since 1950Warnings in force in North Dakota nowThe forecast where you are

3 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.