Tornadoes · United States · Louisiana · 2017

Unrated tornado, Saint Bernard Parish, Louisiana, February 7, 2017

This Unrated tornado ran 7.7 miles across Saint Bernard Parish on February 7, 2017, touching down at 1:04 PM CST and reaching 200 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 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. Unratedthis tornado

    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
Unrated
Date
February 7, 2017
Touchdown
1:04 PM CST (19:04 UTC)
Lifted
1:17 PM CST (19:17 UTC)
On the ground
13 minutes
Path length
7.7 miles (12.5 km)
Path width
200 yards (183 m)
Deaths
0
Injuries
0
County
Saint Bernard Parish
Touchdown point
29.985, -89.571
Lift-off point
29.993, -89.443
Record number
1702071304-01

The damage survey

13 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 70 mph.

  • High resolution imagery visibly depicts the beginning of a tornado damage path matched with tornado debris signature where tornado came ashore from Lake Borgne.
  • High resolution satellite imagery matched with tornado debris signature on KLIX radar imagery estimates the tornado damage path continued through this point where the tornado moved into False Mouth Bay before dissipating over the coastal waters.
  • Evident damage to marsh on high res satellite imagery collocated with TDS.
  • Swath of damage to marsh on high res satellite imagery collocated with TDS.

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

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 13:55 UTC and running to 21:03 UTC.

Issued (UTC)ExpiredProductOffice
13:55 UTC21:03 UTCTornado WatchLIX
16:52 UTC17:15 UTCTornado WarningLIX
17:59 UTC18:30 UTCTornado WarningLIX
18:23 UTC18:45 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 Enhanced Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 16:19 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), 12:00Z

7.1 hours before the tornado, 34 km from the path. February 7, 2017.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 12:00Z on 2017-02-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 889 joules per kilogram, CIN -24, lifted condensation level 562 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 2017-02-07The 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 194 square meters per square second, 0 to 6 km bulk shear 30 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
889 J/kg
Mixed-layer CIN
-24 J/kg
Surface CAPE
255 J/kg
Mixed-layer LCL
562 m above ground
0-6 km bulk shear
30 kt
0-1 km bulk shear
26 kt
0-1 km storm-relative helicity
194 m²/s²
0-3 km storm-relative helicity
190 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.4
0-3 km lapse rate
4.6 K/km

Open this sounding in Storm Lab

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

4.9 hours after it, 34 km from the path. February 8, 2017.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 00:00Z on 2017-02-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1869 joules per kilogram, CIN -14, lifted condensation level 771 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 00:00Z on 2017-02-08The 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 248 square meters per square second, 0 to 6 km bulk shear 67 knots.1939587897Sfc1 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
1869 J/kg
Mixed-layer CIN
-14 J/kg
Surface CAPE
2188 J/kg
Mixed-layer LCL
771 m above ground
0-6 km bulk shear
67 kt
0-1 km bulk shear
38 kt
0-1 km storm-relative helicity
248 m²/s²
0-3 km storm-relative helicity
355 m²/s²
Significant tornado parameter
3.3
Supercell composite
12.0
0-3 km lapse rate
6.0 K/km

Open this sounding in Storm Lab

The surface observations

Bay_st._louis (HSA), 42 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
18:55 UTC64.460.8270° 4 kt1010.5TSRA
19:09 UTC64.460.8360° 13 kt1009.5VCTS
19:55 UTC64.462.6 4 kt1008.8
20:53 UTC69.866.2250° 10 kt181007.8

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
16:51 UTCTORNADO 01 Ne HarahanJefferson, LALARGE TREE LIMBS DOWN AND MINOR ROOF DAMAGE OCCURRED AROUND ELMWOOD. MAX ESTIMATED WINDS AROUND 80 MPH, MAX WIDTH 25 YARDS, AND PATH LENGTH ABOUT 1 MILE.
17:18 UTCHAIL 1.59 Ene New OrleansOrleans, LAPING PONG BALL SIZE HAIL REPORTED IN NEW ORLEANS EAST
17:25 UTCTORNADO 3East New OrleansOrleans, LA*** 25 INJ *** EMERGENCY MANAGEMENT PRELIMINARILY REPORT APPROXIMATELY 60 HOUSES AND STRUCTURES WITH VARYING DEGREES OF DAMAGE. APPROXIMATELY 25 INJURIES REPORTED. -- UPDATE 11/8 1015AM SURVEY CREW CONFIRMS EF3 DAMAGE. D
17:25 UTCTORNADOEast New OrleansOrleans, LA*** 25 INJ *** EMERGENCY MANAGEMENT PRELIMINARILY REPORT APPROXIMATELY 60 HOUSES AND STRUCTURES WITH VARYING DEGREES OF DAMAGE. APPROXIMATELY 25 INJURIES REPORTED.
17:25 UTCTORNADOEast New OrleansOrleans, LASEVERAL REPORTS OF TORNADO TOUCH DOWN. MEDIA REPORTED BUILDING DAMAGE CROWDER AND CHEF MENTEUR. ALSO BUILDING DAMAGED ON OLD GENTILLY ROAD AND TREES DOWN AT MICHOUD

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2017 tornado in LouisianaEvery tornado in Louisiana since 1950Warnings in force in Louisiana nowThe forecast where you are

The other tornadoes of February 7, 2017

15 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
February 79:16 AM CSTEF0Houston, TN0.550$15,000
February 710:20 AM CSTEF2Livingston Parish, LA23.17503
February 710:51 AM CSTEF0Jefferson Parish, LA0.925
February 711:04 AM CSTEF1Ascension Parish, LA6.11501
February 711:12 AM CSTEF3Orleans Parish, LA10.160033
February 711:46 AM CSTEF2Livingston Parish, LA19.02503
February 712:36 PM CSTEF0Saint Bernard Parish, LA2.625
February 71:42 PM CSTEF0Montgomery, AL0.285
February 73:23 PM CSTEF0Covington, AL0.51501$100,000
February 74:36 PM ESTEF1Harris, GA2.3250$150,000
February 74:07 PM CSTEF2Scott, MS4.8880$350,000
February 75:23 PM CSTEF1Jasper, MS3.150$100,000
February 77:40 PM CSTEF0Trigg, KY1.850$25,000
February 710:00 PM ESTEF1Bradford, FL1.175
February 710:37 PM ESTEF1Saint Johns, FL0.5160

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.