Tornadoes · United States · Louisiana · 2017
EF0 tornado, Olivier, Louisiana, August 27, 2017
This EF0 tornado ran 0.1 miles across Iberia Parish on August 27, 2017, touching down at 2:35 PM CDT and reaching 25 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 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
- August 27, 2017
- Touchdown
- 2:35 PM CDT (19:35 UTC)
- Lifted
- 2:36 PM CDT (19:36 UTC)
- On the ground
- 1 minutes
- Path length
- 0.1 miles (0.2 km)
- Path width
- 25 yards (23 m)
- Deaths
- 0
- Injuries
- 0
- County
- Iberia Parish
- Touchdown point
- 29.971, -91.756
- Lift-off point
- 29.972, -91.754
- Record number
- 1708271335-01
What the Weather Service recorded
Harvey moved across the Gulf of Mexico into the central Texas Coast during the last week of August. After the initial landfall, the cyclone moved back into the gulf a couple days later and then made another landfall in Southwest Louisiana during the morning of the 30th. The first rains from the system moved across the region during the afternoon of the 25th and finally ended during the morning of September 1. One to 5 feet of rain fell across Southeast Texas during the week which in some cases was slightly more than a normal yearly rainfall total. Widespread flooding occurred and a new rainfall record was set regarding the total for a tropical cyclone in the United States.
A tornado briefly touched down in a sugar cane|field off of Darnall Road. No damage was reported, but it was|videoed.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
25 minutes of warning. NWS LCH issued a tornado warning for this county at 19:10 UTC, 25 minutes before the tornado touched down, in force until 19:45 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 19:10 UTC | 19:45 UTC | Tornado Warning | LCH |
| 19:40 UTC | 20:00 UTC | Tornado Warning | LCH |
| 19:50 UTC | 23:45 UTC | Flood Advisory | LCH |
| 20:58 UTC | 01:13 UTC | Flash Flood Watch | LCH |
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 Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 16:26 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.
Lake Charles Mun, LA (KLCH), 12:00Z
7.6 hours before the tornado, 140 km from the path. August 27, 2017.
- Mixed-layer CAPE
- 323 J/kg
- Mixed-layer CIN
- -83 J/kg
- Surface CAPE
- 307 J/kg
- Mixed-layer LCL
- 934 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km bulk shear
- 27 kt
- 0-1 km storm-relative helicity
- 181 m²/s²
- 0-3 km storm-relative helicity
- 193 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.0
- 0-3 km lapse rate
- 4.8 K/km
Lake Charles Mun, LA (KLCH), 00:00Z
4.4 hours after it, 140 km from the path. August 28, 2017.
- Mixed-layer CAPE
- 311 J/kg
- Mixed-layer CIN
- -31 J/kg
- Surface CAPE
- 472 J/kg
- Mixed-layer LCL
- 714 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 148 m²/s²
- 0-3 km storm-relative helicity
- 253 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 1.4
- 0-3 km lapse rate
- 5.2 K/km
The radar
The Lake Charles radar (KLCH), 142 km away, was scanning. The volume nearest the touchdown began at 19:32 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 |
|---|---|---|---|---|
| 19:00 UTC | TORNADO | 4 N Erath | Vermilion, LA | PUBLIC RELAYED PHOTO OF A TORNADO VIA SOCIAL MEDIA BETWEEN HWY 338 AND 339 NEAR LEBLANC ELEMENTARY. |
| 19:15 UTC | TORNADO | 3 N Erath | Vermilion, LA | MAYOR CONFIRMED TORNADO DAMAGED A BUILDING OWNED BY THE DRAINAGE BOARD IN THE AREA OF NAUD RD. |
| 19:15 UTC | TORNADO | Lydia | Iberia, LA | EMERGENCY MANAGER REPORTED A TORNADO NEAR LYDIA. |
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 August 27, 2017
4 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.