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.

  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
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)ExpiredProductOffice
18:05 UTC21:41 UTCSevere Thunderstorm WatchSJT
21:35 UTC22:00 UTCSevere Thunderstorm WarningSJT
21:41 UTC05:00 UTCSevere Thunderstorm WatchSJT
22:58 UTC00:00 UTCSevere Thunderstorm WarningSJT
23:29 UTC00:00 UTCSevere Thunderstorm WarningSJT
00:02 UTC03:00 UTCFlood AdvisorySJT
00:43 UTC01:02 UTCSevere Thunderstorm WarningSJT
00:49 UTC01:45 UTCSevere Thunderstorm WarningSJT
01:38 UTC02:15 UTCTornado WarningSJT

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.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 12:00Z on 2020-03-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 325 joules per kilogram, CIN -39, lifted condensation level 492 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Fort Worth, TX at 12:00Z on 2020-03-17The 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 119 square meters per square second, 0 to 6 km bulk shear 28 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
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

Open this sounding in Storm Lab

Fort Worth, TX (KFWD), 00:00Z

2.6 hours after it, 191 km from the path. March 18, 2020.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 00:00Z on 2020-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 307 joules per kilogram, CIN -35, lifted condensation level 659 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°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, Fort Worth, TX at 00:00Z on 2020-03-18The 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 282 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
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

Open this sounding in Storm Lab

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)ReportWhereCountyRemark
21:25 UTCTORNADO8 Nw ThrockmortonThrockmorton, 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.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
March 175:21 PM MDTEF0Curry, NM0.5100

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.