Tornadoes · United States · Alabama · 2021

EF1 tornado, Rainsville, Alabama, December 29, 2021

This EF1 tornado ran 6.0 miles across DeKalb County on December 29, 2021, touching down at 8:21 PM CST and reaching 285 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  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.

The record

Rating
EF1
Date
December 29, 2021
Touchdown
8:21 PM CST (02:21 UTC)
Lifted
8:29 PM CST (02:29 UTC)
On the ground
8 minutes
Path length
6.0 miles (9.7 km)
Path width
285 yards (261 m)
Deaths
0
Injuries
0
County
DeKalb County
Touchdown point
34.517, -85.943
Lift-off point
34.511, -85.838
Record number
2112292021-01

The damage survey

27 damage points were recorded along this path by NWS HUN, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 104 mph.

  • Small limbs about 100 yards in the distance.

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

What the Weather Service recorded

An EF-1 tornado developed in southwest DeKalb County atop Sand Mountain during the mid evening hours along a line of thunderstorms moving east across north central into northeast Alabama. Also, heavy rains led to brief flooding in Cullman County.

An EF-1 tornado with maximum winds of 104 mph touched down just east of County Road 120, where a small outbuilding was destroyed. The tornado moved in an easterly direction, uprooting several trees as it crossed S. Broad Street. As the tornado neared Kirk Road SW, it intensified to its highest strength, snapping or uprooting dozens of trees and causing minor roof damage to several homes. The tornado continued to the east, uprooting more trees along its path as it crossed Highway 35. The tornado began to weaken as it neared Rainbow Road, uprooting a few more trees and destroying a couple of carports. The tornado eventually crossed Church Street where roof damage occurred at BlueScope Steel, before lifting just west of Highway 75.

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

The warnings

3 minutes of warning. NWS HUN issued a tornado warning for this county at 02:18 UTC, 3 minutes before the tornado touched down, in force until 02:45 UTC.

The county was under a tornado watch, issued at 21:53 UTC and running to 02:59 UTC.

Issued (UTC)ExpiredProductOffice
21:53 UTC02:59 UTCTornado WatchHUN
02:18 UTC02:45 UTCTornado WarningHUN

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 forecast that day

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 00:56 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 air that afternoon

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.

Birmingham, AL (KBMX), 00:00Z

2.4 hours before the tornado, 170 km from the path. December 30, 2021.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 00:00Z on 2021-12-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 179 joules per kilogram, CIN -40, lifted condensation level 1065 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Birmingham, AL at 00:00Z on 2021-12-30The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 230 square meters per square second, 0 to 6 km bulk shear 57 knots.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
179 J/kg
Mixed-layer CIN
-40 J/kg
Surface CAPE
44 J/kg
Mixed-layer LCL
1065 m above ground
0-6 km bulk shear
57 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
230 m²/s²
0-3 km storm-relative helicity
292 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

Birmingham, AL (KBMX), 12:00Z

9.6 hours after it, 170 km from the path. December 30, 2021.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 12:00Z on 2021-12-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1031 joules per kilogram, CIN -1, lifted condensation level 644 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Birmingham, AL at 12:00Z on 2021-12-30The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 158 square meters per square second, 0 to 6 km bulk shear 55 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
1031 J/kg
Mixed-layer CIN
-1 J/kg
Surface CAPE
1836 J/kg
Mixed-layer LCL
644 m above ground
0-6 km bulk shear
55 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
158 m²/s²
0-3 km storm-relative helicity
146 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.7
0-3 km lapse rate
5.7 K/km

Open this sounding in Storm Lab

The radar

The Northeast Alabama radar (KHTX), 50 km away, was scanning. The volume nearest the touchdown began at 02:23 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.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
02:21 UTCTSTM WND DMG1 Sw PowellDekalb, ALREPORTED ROOF DAMAGE TO THE SAND MOUNTAIN LARGE ANIMAL CLINIC. REPORT RELAYED VIA SOCIAL MEDIA AND TIME ESTIMATED BASED ON RADAR.
02:21 UTCTORNADO3 Wsw PowellDekalb, ALSTORM DAMAGE SURVEY CONDUCTED BY NWS METEOROLOGISTS AND DEKALB COUNTY EM/SO CONFIRMED AN EF-1 TORNADO. PLEASE CONSULT PNSHUN FOR ADDITIONAL INFORMATION.
02:34 UTCTSTM WND DMG1 Se PowellDekalb, ALPOWER LINES DOWN AT INTERSECTION OF AL 35 AND KIRK ROAD.
02:51 UTCTSTM WND DMG4 Nnw LakeviewDekalb, ALTREE DOWN ON CR 418 IN THE TENBROECK COMMUNITY.
02:51 UTCTSTM WND DMGPowellDekalb, ALDEBRIS ON CR 47 BETWEEN POWELL AND SYLVANIA.
03:00 UTCTSTM WND DMG1 N RainsvilleDekalb, ALDAMAGE TO BLUESCOPE BUILDING AT THE INTERSECTION OF CHURCH AVE. AND WILLINGHAM ST. IN RAINSVILLE.
03:04 UTCTSTM WND DMG1 N SylvaniaDekalb, ALTREE DOWN ON CR 194 NEAR DEKALB COUNTY PUBLIC LAKE.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2021 tornado in AlabamaEvery tornado in Alabama since 1950Warnings in force in Alabama nowThe forecast where you are

The other tornadoes of December 29, 2021

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
December 293:07 PM ESTEF0Decatur, GA0.950$15,000
December 296:27 PM CSTEF1Lamar, AL17.5300
December 299:02 PM CSTEF0Etowah, AL1.2100
December 2910:52 PM ESTEF0Bartow, GA1.9100
December 2910:01 PM CSTEF1Chilton, AL10.9400
December 2912:03 AM ESTEF0Hall, GA2.075
December 2912:19 AM ESTEF1Cherokee, GA0.5100

What this means

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.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.