Tornadoes · United States · Texas · 1991

F3 tornado, San Augustine County, Texas, February 19, 1991

This F3 tornado ran 5.0 miles across San Augustine County on February 19, 1991, touching down at 2:45 AM CST and reaching 300 yards wide. It killed nobody, and did $500,000 to $5 million of property damage.

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 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. F3158 to 206 mphthis tornado

    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
F3
Date
February 19, 1991
Touchdown
2:45 AM CST (08:45 UTC)
Path length
5.0 miles (8.0 km)
Path width
300 yards (274 m)
Deaths
0
Injuries
0
Property damage
$500,000 to $5 million
County
San Augustine County
Touchdown point
31.500, -94.250
Lift-off point
31.550, -94.150
Record number
36

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

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. The outlook in force was issued at 07:06 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.

Longview/Gregg, TX (KGGG), 00:00Z

8.8 hours before the tornado, 99 km from the path. February 19, 1991.

Skew-T log-pSkew-T log-p diagram, Longview/Gregg, TX at 00:00Z on 1991-02-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 766 joules per kilogram, CIN -31, lifted condensation level 566 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Longview/Gregg, TX at 00:00Z on 1991-02-19The 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 252 square meters per square second, 0 to 6 km bulk shear 50 knots.1939587897117136156Sfc1 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
766 J/kg
Mixed-layer CIN
-31 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
566 m above ground
0-6 km bulk shear
50 kt
0-1 km bulk shear
33 kt
0-1 km storm-relative helicity
252 m²/s²
0-3 km storm-relative helicity
268 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

Longview/Gregg, TX (KGGG), 12:00Z

3.2 hours after it, 99 km from the path. February 19, 1991.

Skew-T log-pSkew-T log-p diagram, Longview/Gregg, TX at 12:00Z on 1991-02-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 16 joules per kilogram, CIN -8, lifted condensation level 668 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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, Longview/Gregg, TX at 12:00Z on 1991-02-19The 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 -61 square meters per square second, 0 to 6 km bulk shear 58 knots.1939587897117136Sfc1 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
16 J/kg
Mixed-layer CIN
-8 J/kg
Surface CAPE
21 J/kg
Mixed-layer LCL
668 m above ground
0-6 km bulk shear
58 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
-61 m²/s²
0-3 km storm-relative helicity
182 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.4 K/km

Open this sounding in Storm Lab

The surface observations

Lufkin/Angelina Co. (LFK), 61 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
07:00 UTC6867140° 6 kt1006.8-RA FG
07:04 UTC130° 7 kt1006.8
07:15 UTC150° 6 kt1006.4
08:00 UTC6867200° 5 kt1006.1TSRA FG
08:21 UTC340° 10 kt181008.5
09:00 UTC5958360° 8 kt161010.2TSRA FG
10:00 UTC5957360° 8 kt1010.8TSRA FG

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

This ground now

The live radar over the trackEvery 1991 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of February 19, 1991

3 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
February 1912:40 AM CSTF2Gonzales, TX0.210
February 192:55 AM CSTF2San Augustine, TX5.0200$50,000 to $500,000
February 193:00 AM CSTF1San Augustine, TX0.210

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.