EF1 tornado, Susanna to Grovespring, Missouri, December 10, 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

December 10, 2021

Touchdown

6:13 PM CST (00:13 UTC)

Lifted

6:23 PM CST (00:23 UTC)

On the ground

10 minutes

Path length

6.3 miles (10.2 km)

Path width

75 yards (69 m)

Deaths

0

Injuries

0

Property damage

$350,000

Counties

Webster and Wright counties

Touchdown point

37.345, -92.750

Lift-off point

37.388, -92.648

Record number

2112101813-01

8 damage points were recorded along this path by NWS SGF, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 90 mph.

• Trees uprooted. This is the most likely starting point.
• Tin blown different directions , back to the south west. 3 outbuildings destroyed. Tree damage.
• Numerous snapped and uprooted trees.
• Numerous trees were uprooted or snapped in this area.

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

The Ozarks were on the western edge of a severe thunderstorm and tornado outbreak that occurred from the evening of the 10th to the early morning of the 11th. A very unstable and highly sheared airmass interacted with a strong cold front and upper level disturbance to spark the widespread storm activity. According to the NWS Storm Prediction Center, 121 tornadoes occurred from southwest Missouri eastward into northeast Arkansas, Kentucky, Tennessee, and Illinois. Three tornadoes, each rated EF-1, occurred near West Branson, Walnut Shade and Niangua. In addition, there were over 30 reports of damaging wind gusts over 60 mph, and several reports with hail up to golf ball size. Due to the fast movement of the storms, rainfall accumulations were generally one half inch or less.

A National Weather Service storm survey concluded that an EF-1 tornado with maximum winds of 90 mph touched down southeast of Niangua and travelled northeast for just over 6 miles into Wright County before lifting a few miles west-southwest of Grovespring. This tornado damaged or destroyed numerous outbuildings, snapped or uprooted numerous trees, caused minor damage to a few homes as well as flipping an RV camper as it moved across western Webster County before entering Wright County east of State Highway AC and South of State highway M.

This is the continuation of the storm survey of the EF-1 tornado touched down southeast of Niangua in Webster County and travelled northeast for just over 6 miles into Wright County before lifting a few miles west-southwest of Grovespring. In Wright County the tornado snapped or uprooted numerous trees and caused minor damage a home.

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

14 minutes of warning. NWS SGF issued a tornado warning for this county at 23:59 UTC, 14 minutes before the tornado touched down, in force until 00:30 UTC.

The county was under a tornado watch, issued at 23:20 UTC and running to 02:57 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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:37 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.

Lebanon (LBO), 32 km from the path, in the two hours either side.

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

The Springfield radar (KSGF), 64 km away, was scanning. The volume nearest the touchdown began at 00:09 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 2021 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

32 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.