EF1 tornado, Dorena, Missouri, May 4, 2021

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

May 4, 2021

Touchdown

3:19 AM CDT (08:19 UTC)

Lifted

3:25 AM CDT (08:25 UTC)

On the ground

6 minutes

Path length

3.7 miles (6.0 km)

Path width

400 yards (366 m)

Deaths

0

Injuries

0

Property damage

$85,000

County

Mississippi County

Touchdown point

36.623, -89.262

Lift-off point

36.641, -89.199

Record number

2105040219-01

36 damage points were recorded along this path by NWS MEG and NWS PAH, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 108 mph.

• Another tree nearby was damaged similarly.
• More damage along Levee Rd.
• Big trunk. Other smaller limbs broken in other trees in the vicinity. Inflow winds/gust front driven.
• Just down the road (north). Inflow winds/gust front driven.

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

Clusters of storms, followed by a bowing line of thunderstorms, organized and accelerated east-northeastward during the overnight and wee morning hours. Several pockets of damaging winds accompanied the storms. In addition, a mesovortex along the bowing line of storms produced a tornado near the Mississippi River. A mid-level shortwave trough moved east across the southern Plains. A belt of stronger southwesterly 500 mb winds spread northeast ahead of the trough into southeast Missouri and Arkansas. Instability was sufficient for a round of severe thunderstorms to occur.

The tornado began in open farmland, where it uprooted and snapped several large trees along Highway 77, then proceeded east-northeast toward the Mississippi River, damaging a pivot sprinkler system and totally destroying an equipment shed near the levee. Many trees on the east side of the levee had trunks and limbs snapped, and some trees were uprooted. To the south of the tornado path, sporadic straight-line wind damage occurred to trees along Highway A (a levee road) and along County Road 507 (a levee road). Peak winds were estimated near 105 mph.

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 06:42 UTC and running to 09:16 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 Marginal Risk. The outlook in force was issued at 05:30 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 Paducah radar (KPAH), 63 km away, was scanning. The volume nearest the touchdown began at 08:17 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 2021 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

38 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.