Tornadoes · United States · Texas · 2020
Unrated tornado, Throckmorton, Texas, March 17, 2020
This Unrated tornado ran 0.1 miles across Throckmorton County on March 17, 2020, touching down at 4:25 PM CDT and reaching 35 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 mph
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.
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
- March 17, 2020
- Touchdown
- 4:25 PM CDT (21:25 UTC)
- Lifted
- 4:26 PM CDT (21:26 UTC)
- On the ground
- 1 minutes
- Path length
- 0.1 miles (0.1 km)
- Path width
- 35 yards (32 m)
- Deaths
- 0
- Injuries
- 0
- County
- Throckmorton County
- Touchdown point
- 33.260, -99.280
- Lift-off point
- 33.260, -99.279
- Record number
- 2003171525-01
What the Weather Service recorded
A cold front interacting with an upper level disturbance and plenty of moisture triggered a supercell just northwest of Throckmorton on March 17. Stormchasers videtoped a brief tornado touchdown just northwest of Throckmorton. ||By the afternoon of March 18 into the early morning hours of March 19, a strong upper level low pressure system moved northeast across the Panhandle. Plenty of wind shear and instability interacted with a dryline, copious gulf moisture and triggered an isolated discrete supercell. This tornadic supercell produced at least three tornadoes from southeast Nolan County to Taylor, Jones and Shackelford Counties. Two of the tornadoes were EF-2 at times and did extension damage along its track across four counties.
Storm chasers videotaped a brief touchdown of a tornado 8 miles northwest of Throckmorton.
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.
The county was under a severe thunderstorm watch, issued at 18:05 UTC and running to 21:41 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 18:05 UTC | 21:41 UTC | Severe Thunderstorm Watch | SJT |
| 21:35 UTC | 22:00 UTC | Severe Thunderstorm Warning | SJT |
| 21:41 UTC | 05:00 UTC | Severe Thunderstorm Watch | SJT |
| 22:58 UTC | 00:00 UTC | Severe Thunderstorm Warning | SJT |
| 23:29 UTC | 00:00 UTC | Severe Thunderstorm Warning | SJT |
| 00:02 UTC | 03:00 UTC | Flood Advisory | SJT |
| 00:43 UTC | 01:02 UTC | Severe Thunderstorm Warning | SJT |
| 00:49 UTC | 01:45 UTC | Severe Thunderstorm Warning | SJT |
| 01:38 UTC | 02:15 UTC | Tornado Warning | SJT |
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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 19:58 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.
Fort Worth, TX (KFWD), 12:00Z
9.4 hours before the tornado, 191 km from the path. March 17, 2020.
- Mixed-layer CAPE
- 325 J/kg
- Mixed-layer CIN
- -39 J/kg
- Surface CAPE
- 6 J/kg
- Mixed-layer LCL
- 492 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km bulk shear
- 14 kt
- 0-1 km storm-relative helicity
- 119 m²/s²
- 0-3 km storm-relative helicity
- 126 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
- 0-3 km lapse rate
- 4.4 K/km
Fort Worth, TX (KFWD), 00:00Z
2.6 hours after it, 191 km from the path. March 18, 2020.
- Mixed-layer CAPE
- 307 J/kg
- Mixed-layer CIN
- -35 J/kg
- Surface CAPE
- 1171 J/kg
- Mixed-layer LCL
- 659 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 282 m²/s²
- 0-3 km storm-relative helicity
- 294 m²/s²
- Significant tornado parameter
- 0.5
- Supercell composite
- 7.1
- 0-3 km lapse rate
- 5.4 K/km
The radar
The Dyess AFB radar (KDYX), 80 km away, was scanning. The volume nearest the touchdown began at 21:25 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 |
|---|---|---|---|---|
| 21:25 UTC | TORNADO | 8 Nw Throckmorton | Throckmorton, TX |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2020 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are
The other tornadoes of March 17, 2020
1 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| March 17 | 5:21 PM MDT | EF0 | Curry, NM | 0.5 | 100 |
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.