Tornadoes · United States · Louisiana · 2021

EF1 tornado, Jefferson Parish, Louisiana, April 8, 2021

This EF1 tornado ran 2.3 miles across Jefferson Parish on April 8, 2021, touching down at 4:00 AM CDT and reaching 100 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
April 8, 2021
Touchdown
4:00 AM CDT (09:00 UTC)
Lifted
4:07 AM CDT (09:07 UTC)
On the ground
7 minutes
Path length
2.3 miles (3.8 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Jefferson Parish
Touchdown point
29.906, -90.254
Lift-off point
29.884, -90.227
Record number
2104080300-01

The damage survey

12 damage points were recorded along this path by NWS LIX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EFU. The highest wind the damage implies is 90 mph.

  • Very defined tree and shrub damage path visible on high resolution satellite imagery from April 8, 2021.
  • Evident damage path in the marsh from tornadic waterspout moving ashore.
  • Very defined shrub and grass damage path visible on high resolution satellite imagery from April 8, 2021.

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

The warnings

0 minutes of warning. NWS LIX issued a tornado warning for this county at 09:00 UTC, 0 minutes before the tornado touched down, in force until 09:12 UTC.

Issued (UTC)ExpiredProductOffice
08:42 UTC13:45 UTCFlash Flood WarningLIX
09:00 UTC09:12 UTCTornado WarningLIX
09:22 UTC09:45 UTCTornado WarningLIX

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 05:21 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

9.0 hours before the tornado, 65 km from the path. April 8, 2021.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 00:00Z on 2021-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1186 joules per kilogram, CIN 0, lifted condensation level 722 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Slidell Radar S, LA at 00:00Z on 2021-04-08The 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 147 square meters per square second, 0 to 6 km bulk shear 43 knots.193958Sfc1 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
1186 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
1748 J/kg
Mixed-layer LCL
722 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
23 kt
0-1 km storm-relative helicity
147 m²/s²
0-3 km storm-relative helicity
175 m²/s²
Significant tornado parameter
0.9
Supercell composite
5.8
0-3 km lapse rate
5.6 K/km

Open this sounding in Storm Lab

Slidell Radar S, LA (KSIL), 12:00Z

3.0 hours after it, 65 km from the path. April 8, 2021.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 12:00Z on 2021-04-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 24 joules per kilogram, CIN -260, lifted condensation level 656 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Slidell Radar S, LA at 12:00Z on 2021-04-08The 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 4 square meters per square second, 0 to 6 km bulk shear 52 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
24 J/kg
Mixed-layer CIN
-260 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
656 m above ground
0-6 km bulk shear
52 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

The surface observations

New Orleans - Louis Armstrong (MSY), 11 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
07:00 UTC190° 10 kt1010.5-RA
07:05 UTC190° 9 kt1010.2-RA
07:10 UTC180° 11 kt181010.2-RA
07:15 UTC190° 11 kt171009.8
07:20 UTC200° 11 kt1010.2-RA
07:25 UTC190° 13 kt1010.5-RA
07:30 UTC190° 11 kt1010.2-RA
07:35 UTC180° 10 kt1009.8RA
07:40 UTC190° 11 kt1010.2-RA
07:45 UTC190° 10 kt1009.8-RA
07:50 UTC190° 10 kt1009.8
07:53 UTC7369190° 8 kt1010.2-TSRA
07:55 UTC190° 8 kt1010.2-RA
08:00 UTC200° 7 kt1010.2-RA
08:05 UTC200° 7 kt1010.2-RA
08:10 UTC0° 0 kt1009.8+RA BR
08:15 UTC280° 5 kt1010.5+RA BR
08:20 UTC350° 7 kt1010.5+RA
08:25 UTC350° 4 kt1010.8+RA
08:27 UTC726960° 5 kt1010.5+TSRA BR
08:29 UTC7268100° 10 kt1009.5+TSRA BR
08:30 UTC 11 kt1009.1+RA BR
08:35 UTC 10 kt1008.8+RA BR
08:40 UTC30° 11 kt1008.1+RA BR
08:45 UTC 10 kt1009.5+RA BR
08:50 UTC340° 10 kt1010.2+RA BR
08:53 UTC7067330° 13 kt221010.2+TSRA BR
08:55 UTC 16 kt1010.5+RA BR
09:00 UTC340° 13 kt191011.5+RA FG
09:05 UTC340° 11 kt1010.5+RA BR
09:07 UTC6663350° 11 kt201010.5+TSRA BR
09:10 UTC350° 11 kt1010.5+RA BR
09:15 UTC350° 10 kt1009.8-RA BR
09:20 UTC350° 8 kt1010.5-RA
09:25 UTC360° 5 kt1010.8-RA
09:26 UTC6764360° 6 kt141010.8-TSRA
09:30 UTC350° 8 kt1010.8-RA
09:35 UTC10° 7 kt1010.5
09:40 UTC350° 5 kt1010.8-RA
09:45 UTC340° 4 kt1010.8RA BR
09:50 UTC340° 4 kt1010.8-RA BR
09:53 UTC6764340° 5 kt1010.8-TSRA
09:55 UTC350° 5 kt1010.8-RA
10:00 UTC340° 7 kt1010.8-RA
10:05 UTC340° 8 kt1011.2-RA
10:10 UTC340° 7 kt1010.8-RA
10:10 UTC6764340° 7 kt1010.8-RA
10:15 UTC340° 7 kt1010.8-RA
10:20 UTC340° 5 kt1011.2-RA
10:25 UTC330° 5 kt1011.2-RA
10:30 UTC350° 5 kt1011.2-RA
10:35 UTC340° 7 kt1011.5-RA
10:40 UTC340° 9 kt1011.5-RA
10:45 UTC340° 7 kt1011.5RA
10:50 UTC330° 2 kt1011.5-RA
10:53 UTC6659320° 4 kt1011.5-RA
10:55 UTC310° 4 kt1011.5-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)ReportWhereCountyRemark
07:29 UTCTSTM WND DMG2 Nnw MadisonvilleSt. Tammany, LACORRECTS PREVIOUS TSTM WND DMG REPORT FROM 2 NNW MADISONVILLE. SCATTERED LIGHT TREE DEBRIS ALONG LA HWY 22. A FEW SNAPPED LIMBS. DIAMETER APPEARS TO BE AROUND 4 INCHES ON SOME OF THE BIGGEST.
07:29 UTCTSTM WND DMG2 Nnw MadisonvilleSt. Tammany, LASCATTERED LIGHT TREE DEBRIS ALONG LA HWY 22. A FEW SNAPPED LIMBS. DIAMETER APPEARS TO BE AROUND 4 INCHES ON SOME OF THE BIGGEST.
07:30 UTCTSTM WND DMG1 W MandevilleSt. Tammany, LATREES SNAPPED WITHIN A MILE WEST OF CAUSEWAY BRIDGE.
07:30 UTCTSTM WND DMG2 Nnw MadisonvilleSt. Tammany, LAALMOST ALL BIG LIMBS HAVE ALREADY BEEN PICKED UP BUT A LOT OF LIGHT TREE DEBRIS IN MADISONVILLE OAKS NEIGHBORHOOD.
07:33 UTCTSTM WND DMG2 Ne MadisonvilleSt. Tammany, LAAROUND A DOZEN TREES DOWN IN FAIRVIEW-RIVERSIDE STATE PARK. ALL TREES BLOWN DOWN TO THE E-NE. (THIS IS DAMAGE FROM THE MORNING OF APRIL 8TH).
07:38 UTCMARINE TSTM WIND 431 Ssw MandevilleGmz530, LAWEATHERFLOW SITE AT THE MANDEVILLE LAKEFRONT MEASURED A WIND GUSTS OF 43 MPH.
07:54 UTCTSTM WND DMG2 N LacombeSt. Tammany, LASCATTERED LIGHT TREE DEBRIS.
08:52 UTCMARINE TSTM WIND 396 Wsw East New OrleansGmz530, LALAKEFRONT AIRPORT RECORDED A WIND GUST OF 39MPH.
09:12 UTCFLASH FLOOD1 N KennerJefferson, LAKENNER EMERGENCY MANAGEMENT RELAYED A REPORT FROM POLICE THAT THE INTERSECTION OF CHATEAU AND VINTAGE WAS IMPASSABLE BY AN SUV.
09:32 UTCFLASH FLOOD5 Nnw AvondaleJefferson, LASOUTHEAST SEARCH AND RESCUE REPORTED WATER OVER 2 FEET DEEP ON SOFIA STREET IN RIVER RIDGE.

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 April 8, 2021

10 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 81:18 AM CDTEF0Livingston Parish, LA2.025$5,000
April 82:26 AM CDTEF0Saint Tammany Parish, LA1.425
April 82:45 AM CDTEF0Saint Tammany Parish, LA1.825
April 82:51 AM CDTEF0Saint Tammany Parish, LA6.550
April 83:26 AM CDTEF0Hancock, MS0.775$25,000
April 84:24 AM CDTUnratedJefferson Parish, LA0.850
April 83:15 PM CDTEF0Cumberland, TN5.8125$25,000
April 86:07 PM EDTEF0Scott, TN2.6200
April 86:12 PM EDTEF2Scott, TN1.3300
April 86:15 PM EDTEF2Scott, TN1.8200

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.