Tornadoes · United States · Alabama · 2021

EF0 tornado, Hamilton Arpt to Hamilton, Alabama, March 31, 2021

From Hamilton Arpt to Hamilton, this EF0 tornado ran 1.6 miles across Marion County on March 31, 2021, touching down at 2:31 AM CDT and reaching 90 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 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.

The record

Rating
EF0
Date
March 31, 2021
Touchdown
2:31 AM CDT (07:31 UTC)
Lifted
2:34 AM CDT (07:34 UTC)
On the ground
3 minutes
Path length
1.6 miles (2.6 km)
Path width
90 yards (82 m)
Deaths
0
Injuries
0
County
Marion County
Touchdown point
34.061, -87.996
Lift-off point
34.076, -87.974
Record number
2103310131-01

The damage survey

6 damage points were recorded along this path by NWS BMX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 75 mph.

  • Suspected start point per TDS on KMXX RADAR.

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

A warm front moved pushed northward into north Central Alabama late on March 30th and into the early morning hours on March 31st. A low pressure area developed along the warm front and tracked from west to east across northern Alabama. This feature pooled instability just south of the front and added just enough shear for some rotating and organized storms. Subsequently, three weak and short-lived tornadoes developed. Due to the strong southerly winds and lift near the front, heavy rainfall was observed across northern Alabama. Widespread amounts of 1 to 3 inches of rain were observed with localized amounts of 5 to 6 inches west of I-65. These amounts produced flash flooding in several locations where roads were washed out and or became impassable. Additionally, many local creeks and streams flooded and this eventually lead to river and lake flooding.

National Weather Service meteorologists surveyed damage in southern Marion County and determined that it was consistent with an EF0 tornado, with maximum winds near 80 mph. ||The tornado began in a wooded area just north of Stakehouse Road where several large branches were broken. The tornado then traveled northeast where it crossed I-22 and the intersection of Berryhill Road and Highway 278. In this area, several softwood trees were uprooted and additional large branches were broken. The tornado continued northeast into a deforested area and lifted.

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

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
00:00 UTC22:40 UTCFlash Flood WatchBMX
07:10 UTC07:25 UTCTornado WarningBMX
09:38 UTC13:45 UTCFlash Flood WarningBMX

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 Marginal Risk. The outlook in force was issued at 05:45 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

7.5 hours before the tornado, 149 km from the path. March 31, 2021.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 00:00Z on 2021-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 127 joules per kilogram, CIN -12, lifted condensation level 1179 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 2021-03-31The 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 74 square meters per square second, 0 to 6 km bulk shear 42 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
127 J/kg
Mixed-layer CIN
-12 J/kg
Surface CAPE
273 J/kg
Mixed-layer LCL
1179 m above ground
0-6 km bulk shear
42 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
74 m²/s²
0-3 km storm-relative helicity
179 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2
0-3 km lapse rate
7.2 K/km

Open this sounding in Storm Lab

Birmingham, AL (KBMX), 12:00Z

4.5 hours after it, 149 km from the path. March 31, 2021.

Skew-T log-pSkew-T log-p diagram, Birmingham, AL at 12:00Z on 2021-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 455 joules per kilogram, CIN -3, lifted condensation level 527 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 12:00Z on 2021-03-31The 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 273 square meters per square second, 0 to 6 km bulk shear 44 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
455 J/kg
Mixed-layer CIN
-3 J/kg
Surface CAPE
622 J/kg
Mixed-layer LCL
527 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
34 kt
0-1 km storm-relative helicity
273 m²/s²
0-3 km storm-relative helicity
283 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.5
0-3 km lapse rate
5.9 K/km

Open this sounding in Storm Lab

The surface observations

Haleyville (1M4), 43 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
05:35 UTC190° 10 kt1017.3-RA
05:40 UTC200° 11 kt1017.3-RA
05:45 UTC200° 11 kt1016.9-RA
05:50 UTC180° 11 kt1016.9-RA
05:55 UTC200° 13 kt1017.3-RA
05:56 UTC6766200° 13 kt191016.9RA
06:00 UTC 14 kt1016.9-RA
06:05 UTC200° 14 kt1016.9-RA
06:10 UTC 11 kt1016.9-RA
06:15 UTC200° 11 kt1016.9-RA
06:20 UTC200° 14 kt1016.6-RA
06:25 UTC200° 14 kt1016.9-RA
06:30 UTC 14 kt1016.9RA
06:35 UTC190° 10 kt1016.6RA
06:40 UTC 11 kt1016.9RA
06:45 UTC190° 10 kt1016.6RA
06:50 UTC200° 10 kt1016.6RA
06:55 UTC 11 kt1016.6RA
06:56 UTC6766200° 11 kt201016.6VCTS RA
07:00 UTC210° 10 kt1016.9RA
07:05 UTC 11 kt1016.9RA
07:10 UTC 11 kt161016.3+RA BR
07:15 UTC200° 8 kt1016.6RA BR
07:20 UTC 11 kt1016.6RA
07:25 UTC210° 11 kt1016.9RA
07:30 UTC220° 15 kt1016.9RA
07:35 UTC210° 9 kt1016.6+RA BR
07:40 UTC220° 10 kt1016.6+RA BR
07:45 UTC240° 7 kt1016.6+RA BR
07:50 UTC230° 5 kt1016.3+RA
07:52 UTC64.462.6 4 kt1016.3TSRA
07:55 UTC0° 0 kt1015.9RA
07:56 UTC64630° 0 kt1015.9TSRA
08:00 UTC350° 5 kt1015.6+RA
08:05 UTC330° 5 kt1015.6+RA BR
08:10 UTC250° 8 kt1016.9+RA BR
08:11 UTC64.462.6250° 8 kt1016.9+RA BR
08:15 UTC310° 2 kt1016.3+RA BR
08:20 UTC270° 4 kt1016.6+RA BR
08:25 UTC240° 4 kt1016.3RA BR
08:30 UTC250° 5 kt1016.6RA
08:35 UTC250° 4 kt1016.3RA
08:38 UTC62.662.6230° 3 kt1016.3RA
08:40 UTC240° 2 kt1016.3RA
08:45 UTC220° 5 kt1016.6RA
08:50 UTC230° 5 kt1016.6RA
08:55 UTC220° 5 kt1016.6-RA
08:56 UTC6362210° 6 kt1016.3-RA
09:00 UTC210° 5 kt1016.6-RA
09:05 UTC220° 7 kt1016.6-RA
09:10 UTC230° 7 kt1016.6RA
09:15 UTC210° 7 kt1016.3RA
09:20 UTC220° 8 kt1016.6-RA
09:25 UTC210° 8 kt1016.6RA
09:26 UTC62.662.6210° 8 kt1016.9RA
09:30 UTC240° 8 kt1017.6RA

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

The radar

The Columbus AFB radar (KGWX), 37 km away, was scanning. The volume nearest the touchdown began at 07:30 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
07:31 UTCTORNADO1 Nw Marion County PublMarion, ALAN EF-0 TORNADO TOUCHED DOWN SOUTH OF HAYDEN WITH THE MAJORITY OF THE DAMAGE CONSISTING OF DOWNED TREES. THE TORNADO WAS ON THE GROUND FOR 1.63 MILES. THE MAX WIDTH WAS 90 YARDS AND MAX WINDS WERE 80S MPH.

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 March 31, 2021

4 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
March 311:49 AM CDTEF1Monroe, MS4.3200$200,000
March 313:45 AM CDTEF1Winston, AL1.2305
March 315:44 AM CDTEF1DeKalb, AL3.250
March 318:15 AM CDTEF0Blount, AL0.265

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.