Tornadoes · United States · Alabama · 2021
EF1 tornado, Siloam to Epes, Alabama, March 17, 2021
From Siloam to Epes, this EF1 tornado ran 9.8 miles across Sumter County on March 17, 2021, touching down at 12:57 PM CDT and reaching 475 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.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- March 17, 2021
- Touchdown
- 12:57 PM CDT (17:57 UTC)
- Lifted
- 1:15 PM CDT (18:15 UTC)
- On the ground
- 18 minutes
- Path length
- 9.8 miles (15.7 km)
- Path width
- 475 yards (434 m)
- Deaths
- 0
- Injuries
- 0
- County
- Sumter County
- Touchdown point
- 32.539, -88.134
- Lift-off point
- 32.676, -88.107
- Record number
- 2103171157-01
The damage survey
50 damage points were recorded along this path by NWS BMX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 105 mph.
- Extensive amount of pine trees downed.
- Church. Couple branches snapped nearby.
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 active southern jet stream set-up across the southern United States during the middle of March. Several short-wave troughs became negatively tilted as each one traversed across Texas and towards Alabama. This resulted in a single hail event one Monday, March 15, and significant tornado outbreak on Wednesday, March 17. Many supercells began to develop across Central Alabama by midday Wednesday and continued into the evening hours before a squall line moved through the state. Sufficient instability and strong wind shear produced conditions favorable for tornadoes to develop. The event consisted of twenty-one tornadoes in the NWS Birmingham forecast area.
National Weather Service meteorologists surveyed damage in southern Sumter County and determined that it was consistent with an EF0 tornado, with maximum winds near 75 mph. The tornado began and ended near the intersection of Walker Road and Highway 17. Damage consisted of uprooted trees, broken large tree branches, and shingle damage to a residence.
National Weather Service meteorologists surveyed damage in east central Sumter County and determined that it was consistent with an EF1 tornado, with maximum winds near 105 mph. A tornado touched down on the south side of Highway 28 East just west of Adams Drive. The tornado traveled north and produced mostly tree damage, with numerous hardwood and softwood trees snapped or uprooted. A home in the Bluffport community lost part of its roof and a mobile home was shifted from its blocks. The tornado lifted just north of Port of Epes Highway.
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.
The county was under a tornado watch, issued at 16:36 UTC and running to 23:48 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 03:11 UTC | 03:35 UTC | Severe Thunderstorm Warning | BMX |
| 16:36 UTC | 23:48 UTC | Tornado Watch | BMX |
| 17:59 UTC | 18:25 UTC | Tornado Warning | BMX |
| 18:52 UTC | 19:17 UTC | Tornado Warning | BMX |
| 19:47 UTC | 22:00 UTC | Flood Advisory | BMX |
| 22:26 UTC | 01:30 UTC | Flood Advisory | BMX |
| 23:48 UTC | 02:04 UTC | Tornado Watch | BMX |
| 01:01 UTC | 01:23 UTC | Tornado Warning | BMX |
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 High Risk, with a 0.45 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 16:06 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), 12:00Z
6.0 hours before the tornado, 140 km from the path. March 17, 2021.
- Mixed-layer CAPE
- 658 J/kg
- Mixed-layer CIN
- -112 J/kg
- Surface CAPE
- 2 J/kg
- Mixed-layer LCL
- 759 m above ground
- 0-6 km bulk shear
- 59 kt
- 0-1 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 169 m²/s²
- 0-3 km storm-relative helicity
- 301 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.1
- 0-3 km lapse rate
- 4.5 K/km
Birmingham, AL (KBMX), 00:00Z
6.0 hours after it, 140 km from the path. March 18, 2021.
- Mixed-layer CAPE
- 188 J/kg
- Mixed-layer CIN
- -25 J/kg
- Surface CAPE
- 21 J/kg
- Mixed-layer LCL
- 669 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 336 m²/s²
- 0-3 km storm-relative helicity
- 465 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
- 0-3 km lapse rate
- 5.2 K/km
The surface observations
Demopolis (DYA), 22 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 16:15 UTC | 74.5 | 71.8 | 150° 7 kt | 1012.5 | ||
| 16:35 UTC | 75 | 71 | 160° 6 kt | 1012.2 | ||
| 16:55 UTC | 74 | 70.3 | 140° 6 kt | 1011.9 | RA | |
| 17:15 UTC | 73.2 | 70.7 | 140° 5 kt | 1011.2 | RA | |
| 17:35 UTC | 72.5 | 72.5 | 0° 0 kt | 1010.8 | -RA | |
| 17:55 UTC | 72 | 72 | 120° 4 kt | 1010.5 | -RA | |
| 18:15 UTC | 71.8 | 71.8 | 120° 6 kt | 1009.8 | ||
| 18:35 UTC | 72 | 71.8 | 130° 4 kt | 1010.5 | +RA | |
| 18:55 UTC | 71.4 | 71.4 | 300° 16 kt | 21 | 1008.8 | +RA |
| 19:15 UTC | 71.6 | 71.6 | 150° 10 kt | 1009.5 | -RA | |
| 19:35 UTC | 69 | 67 | 160° 7 kt | 1009.5 | -RA | |
| 19:55 UTC | 67.8 | 67.3 | 130° 4 kt | 1008.8 | -RA |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Birmingham radar (KBMX), 141 km away, was scanning. The volume nearest the touchdown began at 17:56 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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 17:31 UTC | TORNADO | 4 Nne Ward | Sumter, AL | A NWS SURVEY TEAM CONFIRMED DAMAGE FROM A BRIEF EF-0 TORNADO IN SOUTHERN SUMTER COUNTY. THE TORNADO BEGAN AND ENDED NEAR THE INTERSECTION OF WALKER ROAD AND HIGHWAY 17. DAMAGE CONSISTED OF UPROOTED TREES, BROKEN LARGE TR |
| 17:37 UTC | TSTM WND DMG | 4 Nne Ward | Sumter, AL | 20 TO 30 TREES BLOWN DOWN AND MINOR STRUCTURAL DAMAGE NEAR HIGHWAY 17 AND WALKER ROAD. |
| 17:37 UTC | TSTM WND DMG | 4 Nne Ward | Sumter, AL | CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 4 NNE WARD. 20 TO 30 TREES BLOWN DOWN AND MINOR STRUCTURAL DAMAGE NEAR HIGHWAY 17 AND WALKER ROAD. POSSIBLE TORNADO. |
| 17:57 UTC | TORNADO | 4 N Lilita | Sumter, AL | A NWS SURVEY TEAM CONFIRMED DAMAGE FROM AN EF1 TORNADO THAT BEGAN ON THE SOUTH SIDE OF HIGHWAY 28E JUST EAST OF LIVINGSTON AND ENDED NEAR PORT OF EPES HIGHWAY ON APPROACH TO THE TOMBIGBEE RIVER. NUMEROUS HARDWOOD AND SOF |
| 18:02 UTC | TSTM WND DMG | Bluffport | Sumter, AL | SEVERAL TREES WERE BLOWN DOWN AND AT LEAST 4 STRUCTURES WERE DAMAGED IN BLUFFPORT. DAMAGE WAS REPORTED AT HIGHWAY 21 AND VALLEY ROAD. POSSIBLE TORNADO. |
| 19:03 UTC | TORNADO | 2 Ese Mcdowell | Marengo, AL | A NWS SURVEY TEAM CONFIRMED A BRIEF EF0 TORNADO THAT CROSSED LOCK AND DAM ROAD JUST WEST OF FOSCUE PARK, OUTSIDE OF THE CITY OF DEMOPOLIS. DAMAGE CONSISTED OF UPROOTED TREES, LARGE TREE BRANCHES BROKEN, AND SOME PANELING |
| 19:05 UTC | TORNADO | 2 Wnw Demopolis | Sumter, AL | TORNADO OBSERVED VIA TV STATION WEBCAM BROADCAST WITH POWER FLASH AND STORM CHASER DRONE VIDEO. |
| 19:12 UTC | TORNADO | 1 E Mound State Park | Hale, AL | AN EF1 TORNADO PRODUCED DAMAGE FOR 22.03 MILES AND WAS 550 YARDS WIDE AT ITS WIDEST POINT. THE TORNADO STARTED IN MARTIN SLOUGH EAST OF THE WARRIOR RIVER AND LIFTED NNW OF DUNCANVILLE. MODERATE STRUCTURE DAMAGE AND TREE |
| 19:22 UTC | TORNADO | 3 Sw Sweet Water | Marengo, AL | NWS METEOROLOGISTS SURVEYED DAMAGE SOUTH OF SWEET WATER AND DETERMINED THAT IT WAS CONSISTENT WITH AN EF1 TORNADO. THE TORNADO BEGAN ALONG MARENGO COUNTY 6. IT CONTINUED NORTHEASTWARD AND REACHED ITS MAXIMUM INTENSITY AL |
| 19:29 UTC | TORNADO | 1 E Mound State Park | Hale, AL | ROOF DAMAGE TO A NUMBER OF HOUSES IN THE CITY ON BOTH SIDES OF THE COUNTY LINE. SEVERAL BUSINESSES DAMAGED IN MOUNDVILLE. |
| 19:31 UTC | TORNADO | 2 Ene Mound State Park | Tuscaloosa, AL | MULTIPLE HOMES DAMAGED IN THE WATERBURY SUBDIVISION. |
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 17, 2021
32 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| March 17 | 12:03 PM CDT | EF2 | Wayne, MS | 13.1 | 325 | |||
| March 17 | 12:31 PM CDT | EF0 | Sumter, AL | 0.3 | 70 | |||
| March 17 | 12:32 PM CDT | EF2 | Dallas, AL | 5.1 | 1,000 | 2 | ||
| March 17 | 1:16 PM CDT | EF1 | Lincoln, MS | 6.2 | 120 | $20,000 | ||
| March 17 | 1:24 PM CDT | EF1 | Autauga, AL | 2.9 | 150 | |||
| March 17 | 1:56 PM CDT | EF1 | Chilton, AL | 3.0 | 500 | |||
| March 17 | 2:03 PM CDT | EF0 | Marengo, AL | 0.8 | 175 | |||
| March 17 | 2:12 PM CDT | EF1 | Hale, AL | 22.0 | 550 | |||
| March 17 | 2:22 PM CDT | EF1 | Marengo, AL | 2.8 | 500 | |||
| March 17 | 2:26 PM CDT | EF1 | Union Parish, LA | 2.6 | 766 | $150,000 | ||
| March 17 | 2:29 PM CDT | EF0 | Coosa, AL | 0.1 | 25 | |||
| March 17 | 3:09 PM CDT | EF1 | Tuscaloosa, AL | 0.5 | 150 | |||
| March 17 | 3:25 PM CDT | EF1 | Tuscaloosa, AL | 3.5 | 650 | |||
| March 17 | 3:44 PM CDT | EF2 | Wayne, MS to AL | 36.6 | 500 | 2 | ||
| March 17 | 3:54 PM CDT | EF1 | Tuscaloosa, AL | 5.8 | 650 | |||
| March 17 | 4:07 PM CDT | EF1 | Wilkinson, MS | 6.8 | 100 | |||
| March 17 | 4:11 PM CDT | EF0 | Dallas, AL | 1.1 | 75 | |||
| March 17 | 4:30 PM CDT | EF1 | Jefferson, AL | 2.8 | 650 | |||
| March 17 | 4:37 PM CDT | EF0 | Desha, AR | 0.1 | 10 | |||
| March 17 | 4:54 PM CDT | EF0 | Marengo, AL | 1.8 | 75 | |||
| March 17 | 4:56 PM CDT | EF0 | Jefferson, AL | 3.5 | 660 | 1 | ||
| March 17 | 5:12 PM CDT | EF2 | Chilton, AL | 5.8 | 400 | |||
| March 17 | 5:30 PM CDT | EF1 | Barry, MO | 23.7 | 75 | $60,000 | ||
| March 17 | 5:43 PM CDT | EF1 | Blount, AL | 12.9 | 300 | |||
| March 17 | 6:16 PM CDT | EF0 | Lamar, MS | 1.4 | 300 | $75,000 | ||
| March 17 | 7:25 PM CDT | EF0 | Chickasaw, MS | 0.5 | 50 | $25,000 | ||
| March 17 | 7:31 PM CDT | EF0 | Chickasaw, MS | 1.4 | 100 | $25,000 | ||
| March 17 | 7:39 PM CDT | EF0 | Lee, MS | 4.9 | 60 | $35,000 | ||
| March 17 | 7:56 PM CDT | EF0 | Kemper, MS | 0.2 | 80 | $5,000 | ||
| March 17 | 8:35 PM CDT | EF0 | Autauga, AL | 0.1 | 75 | |||
| March 17 | 9:31 PM CDT | EF1 | Cullman, AL | 8.5 | 150 | |||
| March 17 | 10:43 PM CDT | EF0 | Montgomery, AL | 0.3 | 140 |
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.