Tornadoes · United States · Arkansas · 2021
EF0 tornado, Wood Spur, Arkansas, May 9, 2021
This EF0 tornado ran 0.6 miles across St. Francis County on May 9, 2021, touching down at 4:30 PM CDT and reaching 60 yards wide. It killed nobody, and did $25,000 of property damage.
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 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
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
- EF0
- Date
- May 9, 2021
- Touchdown
- 4:30 PM CDT (21:30 UTC)
- Lifted
- 4:32 PM CDT (21:32 UTC)
- On the ground
- 2 minutes
- Path length
- 0.6 miles (1.0 km)
- Path width
- 60 yards (55 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $25,000
- County
- St. Francis County
- Touchdown point
- 34.941, -90.972
- Lift-off point
- 34.936, -90.963
- Record number
- 2105091530-01
What the Weather Service recorded
A cold front pushed into the Mid-South and interacted with an unstable airmass to produce a broken line of showers and thunderstorms that moved across the area from late afternoon into the evening on May 9th. The line interacted with an old outflow boundary to produce a weak tornado in Tipton County. Further south, a bowing segment within the line produced a swath of wind damage across North Mississippi.
A brief tornado damaged a barn and storage building. It removed metal roof panels from a house and uprooted several trees. Peak winds were estimated at 85 mph.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
2 minutes of warning. NWS MEG issued a tornado warning for this county at 21:28 UTC, 2 minutes before the tornado touched down, in force until 22:00 UTC.
The county was under a severe thunderstorm watch, issued at 19:27 UTC and running to 23:39 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 12:00 UTC | 22:00 UTC | Wind Advisory | MEG |
| 19:27 UTC | 23:39 UTC | Severe Thunderstorm Watch | MEG |
| 21:01 UTC | 21:30 UTC | Severe Thunderstorm Warning | MEG |
| 21:20 UTC | 22:00 UTC | Severe Thunderstorm Warning | MEG |
| 21:28 UTC | 22:00 UTC | Tornado Warning | MEG |
| 21:50 UTC | 22:30 UTC | Severe Thunderstorm Warning | MEG |
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 19:50 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.
Little Rock, AR (KLZK), 12:00Z
9.5 hours before the tornado, 94 km from the path. May 9, 2021.
- Mixed-layer CAPE
- 203 J/kg
- Mixed-layer CIN
- -439 J/kg
- Surface CAPE
- 295 J/kg
- Mixed-layer LCL
- 759 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 446 m²/s²
- 0-3 km storm-relative helicity
- 571 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.2 K/km
Little Rock, AR (KLZK), 00:00Z
2.5 hours after it, 94 km from the path. May 10, 2021.
- Mixed-layer CAPE
- 762 J/kg
- Mixed-layer CIN
- -33 J/kg
- Surface CAPE
- 1249 J/kg
- Mixed-layer LCL
- 787 m above ground
- 0-6 km bulk shear
- 48 kt
- 0-1 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- -37 m²/s²
- 0-3 km storm-relative helicity
- 81 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.6
- 0-3 km lapse rate
- 7.1 K/km
The radar
The Memphis radar (KNQA), 109 km away, was scanning. The volume nearest the touchdown began at 21:29 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 |
|---|---|---|---|---|
| 21:30 UTC | TSTM WND DMG | Palestine | St. Francis, AR | ROOF OFF HOUSE. POWER POLES AND BARN BLOWN IN. |
| 21:30 UTC | TORNADO | 4 Nne New Salem | St. Francis, AR | A BRIEF TORNADO DAMAGED A BARN AND STORAGE BUILDING. A HOME SUSTAINED MINOR ROOF DAMAGE AND SEVERAL TREES WERE UPROOTED. |
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 ArkansasEvery tornado in Arkansas since 1950Warnings in force in Arkansas nowThe forecast where you are
The other tornadoes of May 9, 2021
2 more were confirmed in the United States that day.
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.