Tornadoes · United States · Texas · 2006

F1 tornado, Pleak, Texas, April 21, 2006

This F1 tornado ran 1.0 miles across Fort Bend County on April 21, 2006, touching down at 6:15 AM CDT and reaching 30 yards wide. It killed nobody, and did $50,000 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 mphthis tornado

    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
F1
Date
April 21, 2006
Touchdown
6:15 AM CDT (11:15 UTC)
Path length
1.0 miles (1.6 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
Property damage
$50,000
County
Fort Bend County
Touchdown point
29.480, -95.820
Lift-off point
29.480, -95.820
Record number
408

What the Weather Service recorded

Tornado snapped trees off and significantly damaged Meyer Elementary School in Pleak.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The warnings

14 minutes of warning. NWS HGX issued a tornado warning for this county at 11:01 UTC, 14 minutes before the tornado touched down, in force until 11:30 UTC.

The county was under a severe thunderstorm watch, issued at 09:32 UTC and running to 12:54 UTC.

Issued (UTC)ExpiredProductOffice
09:32 UTC12:54 UTCSevere Thunderstorm WatchHGX
10:24 UTC11:30 UTCSevere Thunderstorm WarningHGX
11:01 UTC11:30 UTCTornado WarningHGX
11:29 UTC12:00 UTCSevere Thunderstorm WarningHGX

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 04:35 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.

Corpus Christi, TX (KCRP), 00:00Z

11.3 hours before the tornado, 245 km from the path. April 21, 2006.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 00:00Z on 2006-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1063 joules per kilogram, CIN -254, lifted condensation level 1068 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, Corpus Christi, TX at 00:00Z on 2006-04-21The 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 115 square meters per square second, 0 to 6 km bulk shear 44 knots.193958Sfc1 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
1063 J/kg
Mixed-layer CIN
-254 J/kg
Surface CAPE
1762 J/kg
Mixed-layer LCL
1068 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
15 kt
0-1 km storm-relative helicity
115 m²/s²
0-3 km storm-relative helicity
217 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.2
0-3 km lapse rate
4.7 K/km

Open this sounding in Storm Lab

Corpus Christi, TX (KCRP), 12:00Z

0.7 hours after it, 245 km from the path. April 21, 2006.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 12:00Z on 2006-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2302 joules per kilogram, CIN -12, lifted condensation level 498 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, Corpus Christi, TX at 12:00Z on 2006-04-21The 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 109 square meters per square second, 0 to 6 km bulk shear 52 knots.193958Sfc1 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
2302 J/kg
Mixed-layer CIN
-12 J/kg
Surface CAPE
2381 J/kg
Mixed-layer LCL
498 m above ground
0-6 km bulk shear
52 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
1.5
Supercell composite
6.4
0-3 km lapse rate
5.6 K/km

Open this sounding in Storm Lab

The radar

The Houston radar (KHGX), 72 km away, was scanning. The volume nearest the touchdown began at 11:14 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
11:05 UTCTORNADOPleakFort Bend, TXEXTENSIVE DAMAGE TO MEYER ELEMENTARY SCHOOL JUST EAST OF HIGHWAY 36. NUMEORUS TREES DOWN IN A SOUTHEASTERN PATH AWAY FROM SCHOOL.
11:15 UTCTORNADO 1PleakFort Bend, TXEXTENSIVE DAMAGE TO MEYER ELEMENTARY SCHOOL JUST EAST OF HIGHWAY 36. PORTION OF SCHOOL ROOF PEELED OFF WITH SEVERAL CLASSROOMS DAMAGED. NUMEROUS TREES DOWN APPROACHING THE SCHOOL AND IN A SOUTHEASTERN PATH AWAY FROM THE
11:20 UTCTSTM WND DMG10 Ne Bay CityMatagorda, TXTREE DOWN BETWEEN ASHWOOD AND PLEDGER ON 1728. DAMAGED AUTOMOTIVE WINDSHIELD.
11:50 UTCTSTM WND DMGAlvinBrazoria, TXTREES DOWN IN AND AROUND ALVIN.
11:50 UTCHAIL 0.75RosharonBrazoria, TX

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

This ground now

The live radar over the trackEvery 2006 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of April 21, 2006

1 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 2110:36 PM CDTF0Smith, MS1.050$100,000

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.