Tornadoes · United States · Texas · 1973

F2 tornado, Harris County, Texas, April 26, 1973

This F2 tornado ran 5.2 miles across Harris County on April 26, 1973, touching down at 12:30 AM CST and reaching 100 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 mphthis tornado

    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. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 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.

The record

Rating
F2
Date
April 26, 1973
Touchdown
12:30 AM CST (06:30 UTC)
Path length
5.2 miles (8.4 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
County
Harris County
Touchdown point
29.800, -95.020
Lift-off point
29.730, -94.980
Record number
255

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), 00:00Z

6.5 hours before the tornado, 178 km from the path. April 26, 1973.

Skew-T log-pSkew-T log-p diagram, Lake Charles Mun, LA at 00:00Z on 1973-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1155 joules per kilogram, CIN -40, lifted condensation level 1644 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, Lake Charles Mun, LA at 00:00Z on 1973-04-26The 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 32 square meters per square second, 0 to 6 km bulk shear 47 knots.1939587897117Sfc1 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
1155 J/kg
Mixed-layer CIN
-40 J/kg
Surface CAPE
1605 J/kg
Mixed-layer LCL
1644 m above ground
0-6 km bulk shear
47 kt
0-1 km bulk shear
5 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
108 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.8
0-3 km lapse rate
7.2 K/km

Open this sounding in Storm Lab

Lake Charles Mun, LA (KLCH), 12:00Z

5.5 hours after it, 178 km from the path. April 26, 1973.

Skew-T log-pSkew-T log-p diagram, Lake Charles Mun, LA at 12:00Z on 1973-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -10926, lifted condensation level 2875 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Lake Charles Mun, LA at 12:00Z on 1973-04-26The 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 152 square meters per square second, 0 to 6 km bulk shear 58 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
0 J/kg
Mixed-layer CIN
-10926 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
2875 m above ground
0-6 km bulk shear
58 kt
0-1 km bulk shear
34 kt
0-1 km storm-relative helicity
152 m²/s²
0-3 km storm-relative helicity
79 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.9 K/km

Open this sounding in Storm Lab

The surface observations

Houston/Ellington (EFD), 23 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
05:00 UTC74720° 0 kt1006.1MIBCFG
05:21 UTC240° 4 kt1006.1FG
05:44 UTC290° 5 kt1006.4FG
06:00 UTC74.8472290° 5 kt1006.8MIBCFG
06:05 UTC360° 25 kt321007.5SHRA
06:08 UTC360° 30 kt421008.1+TSRA
06:28 UTC10° 10 kt181007.8SHRA
06:50 UTC10° 10 kt151007.1
07:00 UTC676310° 10 kt151007.1
07:23 UTC360° 8 kt151008.1TS
07:37 UTC340° 15 kt231009.1+TSRA
08:00 UTC6662350° 10 kt191009.8-TSRA

From the Iowa Environmental Mesonet's archive of airport observations.

This ground now

The live radar over the trackEvery 1973 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of April 26, 1973

8 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 264:30 AM CSTF3East Baton Rouge Parish, LA0.370$5,000 to $50,000
April 266:16 AM CSTF2Dunklin, MO2.01002$5,000 to $50,000
April 2611:04 AM CSTF1Bay, FL0.5336$500,000 to $5 million
April 261:30 PM ESTF2Decatur, GA0.173$50,000 to $500,000
April 263:00 PM ESTF1Dougherty, GA0.150$5,000 to $50,000
April 264:00 PM ESTF0Suwannee, FL0.220$5,000 to $50,000
April 264:00 PM ESTF0Marion, FL0.520$500 to $5,000
April 2612:18 AM ESTF1Pender, NC1.5100$5,000 to $50,000

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.