EF2 tornado, Boyd to Junction, Wisconsin, December 15, 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 mph

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mphthis tornado

   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

EF2

Date

December 15, 2021

Touchdown

9:16 PM CST (03:16 UTC)

Lifted

9:23 PM CST (03:23 UTC)

On the ground

7 minutes

Path length

7.4 miles (11.9 km)

Path width

75 yards (69 m)

Deaths

0

Injuries

0

Property damage

$120,000

Counties

Chippewa and Clark counties

Touchdown point

44.901, -90.983

Lift-off point

44.990, -90.900

Record number

2112152116-02

35 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.

• Total destruction of building
• Total destruction of building. There may have been the effect of debris from the adjacent building to the south that helped caused this total destruction.
• The large metal trailer had been lofted 250 feet over the garage, coming to rest just shy of the pond. The photo shows where it was moved to during cleanup, but it had landed to the northeast of the garage.
• Tornado end just northeast of this house.

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

A low pressure system of historic strength led to a variety of high-end weather impacts from the central plains to the Upper Midwest and Great Lakes December 15-16. An unprecedented December severe weather unfolded over portions of Minnesota and Wisconsin Wednesday evening, with the Storm Prediction Center issuing their farthest-north Moderate Risk for the Month of December. A serial derecho moving at 60-70 mph tracked from Kansas to Wisconsin, resulting in over 400 reports of damaging wind and numerous tornadoes. Most of the damage across our area occurred from south-central Minnesota through west-central Wisconsin. The strongest tornado in west central Wisconsin hit Stanley.||Before the thunderstorms, strong southerly winds led to record high temperature at many sites across the Upper Midwest. Temperatures warmed into the mid to upper 50s across much of central Minnesota and western Wisconsin, and even exceeded 60 degrees across southern Minnesota. The warm temperatures melted what was left of the snowpack from the December 10 winter storm, which led to widespread dense fog through much of the morning and afternoon.||After the thunderstorms, strong gradient winds and widespread wind gusts in excess of 50 mph developed for several hours late Wednesday night and into the overnight hours. The Redwood Falls airport measured a gust of 78 mph at 11:30 PM.||Temperatures quickly fell below freezing across western and central Minnesota Wednesday night, causing rain to change over to a wintry mix of freezing drizzle and snow. Snowfall accumulations of 1-4 inches, along with the strong gusty winds, led to low visibility and travel hazards late Wednesday night into Thursday morning.

An intense storm system moved across the Upper Midwest on December 15th and produced a rare severe weather outbreak across western Wisconsin. Eight tornadoes occurred across parts of Trempealeau, Jackson and Clark Counties. Four of these tornadoes were rated EF2 and three EF1. The most substantial damage from the EF2 tornadoes occurred in Clark County. One tornado destroyed a home in the southwest corner of the county near Five Mile Creek west of Neillsville (Clark County). Another tornado caused extensive damage to farms and trees after moving through Stanley (Chippewa County) into the northwest corner of Clark County. An EF0 tornado passed through Perrot State Park (Trempealeau County) and damaged several homes on the west edge of Trempealeau (Trempealeau County). The other tornadoes largely moved through rural areas damaging trees, power lines and farm buildings. Because of the severe weather threat, the Rotary Lights display in La Crosse (La Crosse County) was closed for the first time in over 26 years where two temporary structures were destroyed.

This tornado first caused damage to groves of trees southwest of Stanley, then affected a couple farmsteads. It intensified significantly as it approached Stanley, demolishing an outbuilding and then two outbuildings with a construction business. An historic train depot had a portion of its roof removed. A high tension power line was blown down. About six homes had their roofs removed, and in the northeast edge of Stanley, a roof and outer walls were removed from a portion of a house. The tornado continued into northwestern Clark County where it damaged more trees and outbuildings (see entry from NWS La Crosse).

This EF2 tornado developed in Chippewa County and crossed into Clark County after moving through Stanley. After moving into Clark County, the tornado moved across rural areas damaging farm outbuildings and trees.

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 tornado watch, issued at 23:30 UTC and running to 03:52 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 00:54 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.

Eau Claire (EAU), 44 km from the path, in the two hours either side.

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

The La Crosse radar (KARX), 126 km away, was scanning. The volume nearest the touchdown began at 03:17 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 WisconsinEvery tornado in Wisconsin since 1950Warnings in force in Wisconsin nowThe forecast where you are

124 more were confirmed in the United States that day.

All 125 of them

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.