Tornadoes · United States · Louisiana · 2021
EF0 tornado, Kenner to (Msy)Moisant Fld New, Louisiana, May 18, 2021
From Kenner to (Msy)Moisant Fld New, this EF0 tornado ran 0.3 miles across Jefferson Parish on May 18, 2021, touching down at 3:16 AM CDT and reaching 50 yards wide. It killed nobody, and did $100,000 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 18, 2021
- Touchdown
- 3:16 AM CDT (08:16 UTC)
- Lifted
- 3:17 AM CDT (08:17 UTC)
- On the ground
- 1 minutes
- Path length
- 0.3 miles (0.5 km)
- Path width
- 50 yards (46 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $100,000
- County
- Jefferson Parish
- Touchdown point
- 29.975, -90.260
- Lift-off point
- 29.979, -90.257
- Record number
- 2105180216-01
The damage survey
6 damage points were recorded along this path by NWS LIX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 75 mph.
- Insulation debris strewn about
- Roof torn off building, roof material was badly rusted and corroded.
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
In the overnight hours on May 17th into the early morning on May 18th, a cluster of slow moving severe thunderstorms associated with a weak mid-level disturbance drifted east across southeastern Louisiana. Ample overnight instability and weak steering flow resulted in damaging wind gusts, flash flooding and a few isolated weak tornadoes.
A tornado touched down just north of the river and south of the airport in Kenner and took the roof off a large building. It was noted the roof material was severely corroded and rusted. The tornado moved north and convergence in downed trees was seen just to the east of a cemetery. The tornado continued to track north- northeast, with trees down near the railroad tracks and power lines down just north of the tracks, where it looks like the tornado 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) | Expired | Product | Office |
|---|---|---|---|
| 19:56 UTC | 17:00 UTC | Flash Flood Watch | LIX |
| 08:17 UTC | 08:30 UTC | Severe Thunderstorm Warning | LIX |
| 08:20 UTC | 08:36 UTC | Tornado Warning | LIX |
| 08:57 UTC | 12:00 UTC | High Wind Warning | LIX |
| 09:50 UTC | 12:30 UTC | Flash Flood Warning | LIX |
| 10:26 UTC | 10:58 UTC | Severe Thunderstorm Warning | LIX |
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 General Thunderstorms Risk. The outlook in force was issued at 05:16 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.
Slidell Radar S, LA (KSIL), 00:00Z
8.3 hours before the tornado, 62 km from the path. May 18, 2021.
- Mixed-layer CAPE
- 386 J/kg
- Mixed-layer CIN
- -6 J/kg
- Surface CAPE
- 1930 J/kg
- Mixed-layer LCL
- 682 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 93 m²/s²
- 0-3 km storm-relative helicity
- 155 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.7 K/km
The surface observations
New Orleans - Louis Armstrong (MSY), 2 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 06:20 UTC | 130° 8 kt | 1015.9 | -RA | |||
| 06:25 UTC | 120° 11 kt | 1015.6 | -RA | |||
| 06:30 UTC | 120° 11 kt | 1015.2 | -RA | |||
| 06:35 UTC | 120° 13 kt | 1015.2 | -RA | |||
| 06:40 UTC | 120° 14 kt | 1015.2 | -RA | |||
| 06:45 UTC | 130° 11 kt | 1014.9 | -RA | |||
| 06:50 UTC | 120° 14 kt | 1014.9 | -RA | |||
| 06:53 UTC | 77 | 71 | 120° 12 kt | 1014.9 | -TSRA | |
| 06:55 UTC | 120° 13 kt | 1014.9 | -RA | |||
| 07:00 UTC | 120° 14 kt | 1014.9 | -RA | |||
| 07:05 UTC | 120° 11 kt | 1014.9 | -RA | |||
| 07:10 UTC | 130° 11 kt | 1014.9 | -RA | |||
| 07:15 UTC | 120° 14 kt | 1014.6 | -RA | |||
| 07:20 UTC | 120° 11 kt | 1014.9 | -RA | |||
| 07:25 UTC | 120° 11 kt | 1014.9 | -RA | |||
| 07:30 UTC | 120° 11 kt | 1014.9 | -RA | |||
| 07:35 UTC | 130° 10 kt | 1015.2 | -RA | |||
| 07:40 UTC | 230° 8 kt | 1015.2 | -RA | |||
| 07:45 UTC | 8 kt | 1015.6 | RA | |||
| 07:50 UTC | 330° 5 kt | 1015.2 | RA BR | |||
| 07:53 UTC | 72 | 68 | 340° 9 kt | 1015.2 | TSRA BR | |
| 07:55 UTC | 10° 8 kt | 1015.2 | RA BR | |||
| 08:00 UTC | 350° 7 kt | 1014.9 | -RA | |||
| 08:05 UTC | 9 kt | 1014.6 | -RA | |||
| 08:10 UTC | 9 kt | 1014.6 | -RA | |||
| 08:15 UTC | 9 kt | 1014.6 | RA | |||
| 08:20 UTC | RA BR | |||||
| 08:25 UTC | +RA BR | |||||
| 08:28 UTC | 70 | 67 | 340° 12 kt | 1015.2 | TS BR | |
| 08:30 UTC | 11 kt | 21 | 1015.2 | +RA BR | ||
| 08:35 UTC | 11 kt | 21 | 1015.2 | +RA BR | ||
| 08:40 UTC | 20° 5 kt | 1015.2 | RA BR | |||
| 08:45 UTC | 1015.2 | RA BR | ||||
| 08:50 UTC | 14 kt | 21 | 1015.2 | RA BR | ||
| 08:53 UTC | 70 | 67 | 110° 14 kt | 1015.2 | -TSRA BR | |
| 08:55 UTC | 14 kt | 21 | 1015.2 | -RA | ||
| 09:00 UTC | 14 kt | 21 | 1015.2 | -RA | ||
| 09:05 UTC | 120° 5 kt | 21 | 1015.2 | -RA | ||
| 09:10 UTC | 120° 5 kt | 21 | 1015.2 | +RA BR | ||
| 09:15 UTC | 120° 5 kt | 21 | 1015.2 | +RA BR | ||
| 09:20 UTC | 120° 5 kt | 21 | 1015.2 | +RA BR | ||
| 09:25 UTC | 120° 7 kt | 21 | 1015.2 | RA | ||
| 09:30 UTC | 120° 7 kt | 21 | 1015.2 | RA | ||
| 09:35 UTC | 120° 7 kt | 21 | 1015.2 | RA | ||
| 09:40 UTC | 120° 7 kt | 21 | 1015.2 | -RA | ||
| 09:45 UTC | 120° 7 kt | 21 | 1015.2 | -RA | ||
| 09:50 UTC | 120° 8 kt | 21 | 1014.9 | -RA | ||
| 09:53 UTC | 69 | 66 | 120° 8 kt | 1014.9 | -TSRA | |
| 09:55 UTC | 120° 8 kt | 21 | 1014.9 | -RA | ||
| 10:00 UTC | 120° 8 kt | 21 | 1014.9 | -RA | ||
| 10:05 UTC | 120° 8 kt | 21 | 1014.9 | -RA | ||
| 10:10 UTC | 120° 8 kt | 21 | 1014.9 | -RA | ||
| 10:15 UTC | 120° 8 kt | 21 | 1014.9 | -RA |
From the Iowa Environmental Mesonet's archive of airport observations.
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 |
|---|---|---|---|---|
| 07:50 UTC | TORNADO | 2 Wsw Madisonville | St. Tammany, LA | A TORNADO MOVED ONSHORE NEAR GUSTE ISLAND IN MADISONVILLE AND TRACKED N-NW ACROSS MAINLY UNINHABITED SWAMP LAND. SPORADIC SOFTWOOD AND HARDWOOD TREE DAMAGE WAS NOTED ON THE EASTERN SHORE OF AN INLET. EF-0 WITH ESTIMATED |
| 08:16 UTC | TORNADO | 1 W Kenner | Jefferson, LA | AN EF0 TORNADO, WITH A PATH WIDTH OF 50 YARDS, A PATH LENGTH OF 0.3 MILES AND MAXIMUM WINDS OF 75 MPH, TOUCHED DOWN JUST NORTH OF THE RIVER AND SOUTH OF THE AIRPORT IN KENNER AND TOOK THE ROOF OFF A LARGE BUILDING. IT WA |
| 08:30 UTC | FLASH FLOOD | 1 Ese Hahnville | St. Charles, LA | NUMEROUS ROADS IMPASSABLE IN THE HAHNVILLE AREA. |
| 08:30 UTC | FLASH FLOOD | Norco | St. Charles, LA | NUMEROUS ROADS IMPASSABLE IN THE NORCO AREA. |
| 09:37 UTC | FLASH FLOOD | Destrehan | St. Charles, LA | NUMEROUS ROADS IMPASSABLE IN THE DESTRAHAN AREA. |
| 10:43 UTC | TSTM WND DMG | Violet | St. Bernard, LA | WIND DAMAGE IN VIOLET ON SOUTH LAKE BOULEVARD. DAMAGE CONSISTS OF SOME METAL AWNINGS AND A PATIO COVER ALONG WITH A WOODEN GAZEBO LIFTED AND MOVED. SEVERAL LARGE OAK TREE BRANCHES ALSO DOWN. |
| 10:50 UTC | FLASH FLOOD | 4 Ssw New Orleans | Orleans, LA | SEVERAL STREETS IMPASSABLE ACROSS NEW ORLEANS, MOSTLY IN THE UPTOWN AREA. |
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 LouisianaEvery tornado in Louisiana since 1950Warnings in force in Louisiana nowThe forecast where you are
The other tornadoes of May 18, 2021
9 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 18 | 2:51 AM CDT | EF1 | Saint Tammany Parish, LA | 1.6 | 175 | |||
| May 18 | 2:16 PM CDT | EF1 | Clarke, MS | 1.4 | 150 | $50,000 | ||
| May 18 | 2:59 PM CDT | EF0 | Jefferson Davis, MS | 1.0 | 300 | $75,000 | ||
| May 18 | 3:53 PM CDT | EF0 | Simpson, MS | 1.5 | 300 | $15,000 | ||
| May 18 | 4:54 PM CDT | EF1 | Lavaca, TX | 1.6 | 150 | $20,000 | ||
| May 18 | 6:03 PM CDT | EF0 | Dawson, TX | 0.1 | 50 | |||
| May 18 | 6:42 PM CDT | EF1 | Fayette, TX | 3.3 | 400 | $100,000 | ||
| May 18 | 7:23 PM CDT | EF0 | Conway, AR | 0.1 | 25 | $25,000 | ||
| May 18 | 9:16 PM CDT | EF0 | Scurry, TX | 0.0 | 50 |
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.