Tornadoes · United States · Texas · 2004

F0 tornado, San Saba County, Texas, June 21, 2004

This F0 tornado ran 0.1 miles across San Saba County on June 21, 2004, touching down at 7:15 PM CDT and reaching 25 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 mphthis tornado

    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 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
F0
Date
June 21, 2004
Touchdown
7:15 PM CDT (00:15 UTC)
Path length
0.1 miles (0.2 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
San Saba County
Touchdown point
31.430, -99.050
Lift-off point
31.430, -99.050
Record number
252

The warnings

3 minutes of warning. NWS SJT issued a tornado warning for this county at 00:12 UTC, 3 minutes before the tornado touched down, in force until 01:00 UTC.

Issued (UTC)ExpiredProductOffice
00:12 UTC01:00 UTCTornado WarningSJT
00:56 UTC02:00 UTCSevere Thunderstorm WarningSJT
01:18 UTC02:00 UTCTornado WarningSJT
01:57 UTC02:45 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 General Thunderstorms Risk. The outlook in force was issued at 19:46 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), 00:00Z

0.3 hours before the tornado, 227 km from the path. June 22, 2004.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 00:00Z on 2004-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1701 joules per kilogram, CIN -79, lifted condensation level 1322 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 2004-06-22The 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 88 square meters per square second, 0 to 6 km bulk shear 34 knots.1939Sfc1 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
1701 J/kg
Mixed-layer CIN
-79 J/kg
Surface CAPE
2816 J/kg
Mixed-layer LCL
1322 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
88 m²/s²
0-3 km storm-relative helicity
122 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.8
0-3 km lapse rate
6.7 K/km

Open this sounding in Storm Lab

Fort Worth, TX (KFWD), 12:00Z

11.7 hours after it, 227 km from the path. June 22, 2004.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 12:00Z on 2004-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 188 joules per kilogram, CIN -79, lifted condensation level 1337 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 2004-06-22The 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 -76 square meters per square second, 0 to 6 km bulk shear 15 knots.1939Sfc1 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
188 J/kg
Mixed-layer CIN
-79 J/kg
Surface CAPE
561 J/kg
Mixed-layer LCL
1337 m above ground
0-6 km bulk shear
15 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
-76 m²/s²
0-3 km storm-relative helicity
-1 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-1.1
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

The surface observations

Brownwood Municipal (BWD), 41 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
22:25 UTC87.869.8100° 6 kt1007.8
22:45 UTC8669.860° 7 kt1008.5
23:05 UTC80.668320° 55 kt661008.5
23:25 UTC78.868320° 9 kt1008.5
23:45 UTC75.271.6240° 10 kt1009.1
00:05 UTC73.471.6300° 4 kt1008.5
00:25 UTC73.471.6340° 5 kt1008.5
00:45 UTC73.471.6100° 7 kt1007.5
01:05 UTC73.471.6130° 8 kt1007.8
01:25 UTC73.471.6130° 9 kt1007.8
01:45 UTC73.471.6110° 10 kt1007.8
02:05 UTC75.271.6130° 8 kt1007.8

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

What was reported nearby

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

Time (UTC)ReportWhereCountyRemark
23:05 UTCTSTM WND GST 76BrownwoodBrown, TXRECORDED BY BROWNWOOD AWOS
00:43 UTCTSTM WND GST 03 E DooleMcculloch, TXCAR REPORTED TO HAVE BEEN BLOWN OFF OF A ROAD EAST OF DOOLE
00:45 UTCTSTM WND GST 70LohnMcculloch, TXMANY TREE LIMBS BLOWN DOWN IN THE LOHN AREA

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

This ground now

The live radar over the trackEvery 2004 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of June 21, 2004

12 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
June 213:44 PM EDTF0Tattnall, GA0.150
June 216:05 PM EDTF0Brantley, GA0.50
June 216:10 PM MDTF0Union, NM0.1100
June 217:11 PM CDTF0Potter, TX0.125
June 217:16 PM CDTF0Potter, TX0.125
June 217:34 PM CDTF0Randall, TX0.125
June 217:48 PM CDTF0Randall, TX0.125
June 217:51 PM CDTF0Randall, TX0.125
June 218:03 PM CDTF0Randall, TX0.125
June 218:17 PM CDTF1Randall, TX0.450$230,000
June 218:17 PM CDTF0Randall, TX0.125
June 219:00 PM CDTF0Swisher, TX0.550

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.