EF0 tornado, Karnack, Texas, January 11, 2020

1. EF065 to 85 mphthis tornado

   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. 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.

Rating

EF0

Date

January 11, 2020

Touchdown

12:30 AM CST (06:30 UTC)

Lifted

12:33 AM CST (06:33 UTC)

On the ground

3 minutes

Path length

3.0 miles (4.8 km)

Path width

100 yards (91 m)

Deaths

0

Injuries

0

Property damage

$15,000

County

Harrison County

Touchdown point

32.640, -94.211

Lift-off point

32.655, -94.163

Record number

2001110030-01

13 damage points were recorded along this path by NWS SHV, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 85 mph.

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

An upper level longwave trough emerged out of the Intermountain West and into the Central and Southern Plains during the daytime and evening hours of January 10th. A strong southerly return flow commenced out ahead of the trough during the 8th-9th, allowing for unseasonably warm and humid conditions to advance northward across Southern Oklahoma, much of Central and Eastern Texas, as well as Louisiana, Arkansas, and the Lower Mississippi Valley. Meanwhile, an intensifying surface low pressure system and associated dry line developed along the Red River of North Texas into Southern Oklahoma during the afternoon hours, which spread east northeast across the Ark-La-Tex during the early morning hours on January 11th. With afternoon temperatures climbing into the mid 70s ahead of this trough, moderate instability developed across the broad warm sector, with very strong wind shear in place as large scale forcing increased ahead of the trough axis across East Texas, Southeast Oklahoma, Southwest Arkansas, and North Louisiana. Thus, an axis of strong to severe showers and thunderstorms developed during the evening hours across Southeast Oklahoma, adjacent sections of Southwest Arkansas and East Texas, which advanced east into North Louisiana during the early morning hours of the 11th. Damaging winds downed trees and power lines across portions of East Texas, with even multiple tornadoes touching down along the line of severe thunderstorms. Unfortunately, a man was killed when a tornado touched down west of Nacogdoches and a tree fell on his mobile home. These storms also produced locally heavy rainfall, with amounts of one to three inches, with isolated higher amounts up to four inches recorded across much of this area, resulting in isolated instances of flash flooding. These storms continued to intensify during the late evening and early morning hours as they moved into extreme Eastern Texas and Western Louisiana, producing more in the way of widespread wind damage and isolated tornadoes.

An EF-0 tornado with estimated maximum winds near 85 mph touched down off of County Road 2108 and snapped small and large branches along its path. The tornado crossed Highway 43 where it tore off a wooden front porch and gutters off of a home. It then crossed County Road 2600 before lifting near Farm to Market Road 134 before entering the Longhorn Army Ammunition Plant.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

24 minutes of warning. NWS SHV issued a tornado warning for this county at 06:06 UTC, 24 minutes before the tornado touched down, in force until 06:30 UTC.

The county was under a tornado watch, issued at 23:40 UTC and running to 08:00 UTC.

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 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.

The Shreveport radar (KSHV), 39 km away, was scanning. The volume nearest the touchdown began at 06:31 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.

Local storm reports within 60 km of the path, in the three hours either side.

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

The live radar over the trackEvery 2020 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

62 more were confirmed in the United States that day.

All 63 of them

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.