Tornadoes · United States · Texas · 2009

EF1 tornado, Ben Bolt, Texas, May 24, 2009

This EF1 tornado ran 0.2 miles across Jim Wells County on May 24, 2009, touching down at 4:45 PM CDT and reaching 50 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 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 mph

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

  2. EF186 to 110 mphthis tornado

    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
EF1
Date
May 24, 2009
Touchdown
4:45 PM CDT (21:45 UTC)
Lifted
4:46 PM CDT (21:46 UTC)
On the ground
1 minutes
Path length
0.2 miles (0.4 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$50,000
County
Jim Wells County
Touchdown point
27.675, -98.068
Lift-off point
27.675, -98.064
Record number
0905241545-01

What the Weather Service recorded

An outflow boundary, from storms to the north, intersected the updraft a developing storm just north of Ben Bolt, and helped to produce a tornado near the community of Green Acres.

NWS Storm Survey revealed an EF-1 tornado touched down near the community of Green Acres, at the intersection of CR 480 and CR 481. The tornado was 50 yards wide and traveled roughly two tenths of a mile before lifting up. One mobile home trailer was completely destoyed while a roof was removed from another. Numerous large tree branches were broken along along the path. A couple of trees were uprooted and one tree trunk was completely snapped. Winds were estimated at 105 mph.

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

The warnings

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

Issued (UTC)ExpiredProductOffice
21:48 UTC22:09 UTCSevere Thunderstorm 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 19:42 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

9.8 hours before the tornado, 72 km from the path. May 24, 2009.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 12:00Z on 2009-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1060 joules per kilogram, CIN -45, lifted condensation level 846 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 2009-05-24The 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 -26 square meters per square second, 0 to 6 km bulk shear 22 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
1060 J/kg
Mixed-layer CIN
-45 J/kg
Surface CAPE
862 J/kg
Mixed-layer LCL
846 m above ground
0-6 km bulk shear
22 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
18 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

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

2.2 hours after it, 72 km from the path. May 25, 2009.

Skew-T log-pSkew-T log-p diagram, Corpus Christi, TX at 00:00Z on 2009-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1083 joules per kilogram, CIN -79, lifted condensation level 1444 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 2009-05-25The 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 -37 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
1083 J/kg
Mixed-layer CIN
-79 J/kg
Surface CAPE
2933 J/kg
Mixed-layer LCL
1444 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
6.6 K/km

Open this sounding in Storm Lab

The surface observations

Alice International Airport (ALI), 8 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:53 UTC956310° 9 kt1008.8
20:28 UTC9564.4350° 7 kt1008.1VCTS
20:43 UTC96.864.410° 8 kt1007.8
20:53 UTC956330° 14 kt201007.8
21:27 UTC84.269.850° 9 kt1007.8+TSRA
21:53 UTC8870210° 6 kt1007.5-TSRA
22:12 UTC8671.6180° 8 kt1007.1
22:53 UTC8771130° 3 kt1006.4
23:09 UTC89.669.830° 3 kt1006.8VCTS
23:26 UTC91.466.2350° 6 kt1006.8

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

The radar

The Corpus Christi radar (KCRP), 56 km away, was scanning. The volume nearest the touchdown began at 21:43 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
21:45 UTCTORNADO4 N Ben BoltJim Wells, TXTRAILER DAMAGED...POWER LINES DOWN...TREES UPROOTED BY TORNADO IN GREEN ACRES SUBDIVISION.

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 May 24, 2009

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 242:15 PM EDTEF1Aroostook, ME2.7200
May 2412:30 PM MDTEF0Beaver, UT0.110
May 242:28 PM CDTEF0Hale, TX0.225
May 242:12 PM MDTEF0Adams, CO0.150
May 243:42 PM MDTEF0Douglas, CO0.050
May 245:25 PM CDTEF0Dyer, TN to MO5.225
May 245:58 PM CDTEF0Floyd, TX0.375

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.