Tornadoes · United States · Texas · 2009

EF0 tornado, Rockport, Texas, August 30, 2009

This EF0 tornado ran 3.5 miles across Aransas County on August 30, 2009, touching down at 3:58 PM CDT and reaching 25 yards wide. It killed nobody, and did $10,000 of property damage.

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 mphthis tornado

    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. 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
EF0
Date
August 30, 2009
Touchdown
3:58 PM CDT (20:58 UTC)
Lifted
4:02 PM CDT (21:02 UTC)
On the ground
4 minutes
Path length
3.5 miles (5.6 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
Property damage
$10,000
County
Aransas County
Touchdown point
27.983, -97.149
Lift-off point
27.933, -97.151
Record number
0908301458-01

What the Weather Service recorded

A tornado touched near Highway 188, just southwest of Rockport. The tornado continued south crossing Highway 35, just north of Aransas Pass, then dissipated.

Damage was confined to power lines blown down north of Aransas Pass, along Highway 35.

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

The warnings

2 minutes of warning. NWS CRP issued a tornado warning for this county at 20:56 UTC, 2 minutes before the tornado touched down, in force until 22:00 UTC.

Issued (UTC)ExpiredProductOffice
20:56 UTC22:00 UTCTornado WarningCRP

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 19:59 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), 12:00Z

9.0 hours before the tornado, 31 km from the path. August 30, 2009.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 12:00Z on 2009-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 657 joules per kilogram, CIN -94, lifted condensation level 1173 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 2009-08-30The 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 -1 square meters per square second, 0 to 6 km bulk shear 15 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
657 J/kg
Mixed-layer CIN
-94 J/kg
Surface CAPE
846 J/kg
Mixed-layer LCL
1173 m above ground
0-6 km bulk shear
15 kt
0-1 km bulk shear
2 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
-12 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.0 K/km

Open this sounding in Storm Lab

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

3.0 hours after it, 31 km from the path. August 31, 2009.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 00:00Z on 2009-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 298 joules per kilogram, CIN -135, lifted condensation level 1556 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 2009-08-31The 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 -159 square meters per square second, 0 to 6 km bulk shear 26 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
298 J/kg
Mixed-layer CIN
-135 J/kg
Surface CAPE
1023 J/kg
Mixed-layer LCL
1556 m above ground
0-6 km bulk shear
26 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
-159 m²/s²
0-3 km storm-relative helicity
-179 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.4
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

The surface observations

Ingleside (TFP), 8 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:00 UTC94.663150° 3 kt1013.2
19:20 UTC95.264.2170° 6 kt1012.5
19:40 UTC9664.8170° 6 kt1012.2
20:00 UTC98.462.8150° 9 kt1011.9
20:20 UTC99.763.3130° 12 kt171011.5
20:40 UTC85.867.8340° 43 kt521012.5+TSRA
21:00 UTC75.669.80° 0 kt1013.5+TSRA
21:21 UTC75.671.8100° 17 kt291012.9-TSRA
21:40 UTC76.873.2120° 14 kt1012.5-TSRA
22:00 UTC7874130° 12 kt1012.2VCTS
22:21 UTC78.473.8130° 11 kt1012.2
22:40 UTC79.574.3150° 9 kt1012.2

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

The radar

The Corpus Christi radar (KCRP), 40 km away, was scanning. The volume nearest the touchdown began at 20:57 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
20:58 UTCTORNADO7 Sw RockportAransas, TXPUBLIC REPORTED TORNADO ALONG HIGHWAY 188
20:59 UTCTORNADO3 N Aransas PassAransas, TXPUBLIC REPORTED TORNADO ALONG HIGHWAY 35
21:50 UTCMARINE TSTM WIND 51Flour BluffNueces, TXTHE CORPUS CHRISTI NAVAL AIR STATION ASOS MEASURED A 51 MPH WIND GUST.

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

This ground now

The live radar over the trackEvery 2009 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of August 30, 2009

1 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 309:50 PM CDTEF1Galveston, TX0.3503$500,000

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.