Tornadoes · United States · Texas · 2011

EF0 tornado, Onalaska, Texas, April 25, 2011

This EF0 tornado ran 0.1 miles across Polk County on April 25, 2011, touching down at 12:30 AM CDT and reaching 20 yards wide. It killed nobody, and did $1,000 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
April 25, 2011
Touchdown
12:30 AM CDT (05:30 UTC)
Path length
0.1 miles (0.2 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
Property damage
$1,000
County
Polk County
Touchdown point
30.833, -95.083
Lift-off point
30.833, -95.083
Record number
1104252330-01

What the Weather Service recorded

Severe thunderstorms erupted along the dry line with the help of a shortwave aloft and produced large hail, strong damaging winds and tornadoes.

An EF0 tornado caused little damage at Walkers Waterfront.

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

The warnings

34 minutes of warning. NWS HGX issued a tornado warning for this county at 04:56 UTC, 34 minutes before the tornado touched down, in force until 06:00 UTC.

Issued (UTC)ExpiredProductOffice
19:43 UTC04:00 UTCTornado WatchHGX
03:11 UTC04:00 UTCSevere Thunderstorm WarningHGX
04:09 UTC05:00 UTCSevere Thunderstorm WarningHGX
04:16 UTC05:00 UTCSevere Thunderstorm WarningHGX
04:33 UTC05:00 UTCTornado WarningHGX
04:56 UTC06:00 UTCTornado WarningHGX
04:59 UTC06:00 UTCSevere Thunderstorm WarningHGX
06:00 UTC07:00 UTCSevere Thunderstorm WarningHGX
06:43 UTC07:30 UTCSevere Thunderstorm WarningHGX
21:56 UTC02:51 UTCTornado WatchHGX

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, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:32 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.

Lake Charles Mun, LA (KLCH), 00:00Z

5.5 hours before the tornado, 197 km from the path. April 26, 2011.

Skew-T log-pSkew-T log-p diagram, Lake Charles Mun, LA at 00:00Z on 2011-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2759 joules per kilogram, CIN 0, lifted condensation level 581 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, Lake Charles Mun, LA at 00:00Z on 2011-04-26The 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 86 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
2759 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
4046 J/kg
Mixed-layer LCL
581 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
1.5
Supercell composite
8.4
0-3 km lapse rate
5.2 K/km

Open this sounding in Storm Lab

Lake Charles Mun, LA (KLCH), 12:00Z

6.5 hours after it, 197 km from the path. April 26, 2011.

Skew-T log-pSkew-T log-p diagram, Lake Charles Mun, LA at 12:00Z on 2011-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1202 joules per kilogram, CIN -116, lifted condensation level 671 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, Lake Charles Mun, LA at 12:00Z on 2011-04-26The 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 112 square meters per square second, 0 to 6 km bulk shear 39 knots.19395878Sfc1 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
1202 J/kg
Mixed-layer CIN
-116 J/kg
Surface CAPE
388 J/kg
Mixed-layer LCL
671 m above ground
0-6 km bulk shear
39 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
112 m²/s²
0-3 km storm-relative helicity
189 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.6
0-3 km lapse rate
4.2 K/km

Open this sounding in Storm Lab

The surface observations

Huntsville Municipal Airport (UTS), 49 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
03:53 UTC7869180° 14 kt221002
04:33 UTC78.869.8190° 11 kt241002VCTS
04:53 UTC78700° 4 kt1002.4TS
05:18 UTC69.864.4100° 3 kt1003.4+TSRA
05:29 UTC66.264.4 1003.4-TSRA BR
05:48 UTC66.264.4 1002.4-TSRA BR
05:53 UTC6865170° 5 kt1002TS
06:20 UTC6866.2190° 3 kt1001.7VCTS
06:44 UTC6866.2 1001.7BR
06:53 UTC6867 1002
07:17 UTC69.868 1002.4BR

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

The radar

The Houston radar (KHGX), 151 km away, was scanning. The volume nearest the touchdown began at 05:30 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
04:30 UTCHAIL 0.756 Ne TrinityTrinity, TX
04:51 UTCHAIL 0.8810 Ese TrinityTrinity, TXNEAR FM 356 AT BARRETS LANDING NICKEL HAIL.
05:15 UTCTSTM WND DMGRiversideWalker, TXWALKER COUNTY SHERRIF HAD NUMEROUS REPORTS OF TREES DOWN IN AND AROUND RIVERSIDE.
05:15 UTCHAIL 0.54 E RiversideWalker, TX
05:30 UTCTORNADO3 Ne OnalaskaPolk, TXPUBLIC REPORTED A POSSIBLE TORNADO AT WALKERS WATERFRONT ON LAKE LIVINGSTON. NORTH OF TRIPLE CREEK LOOP AND FM3152. TIME APPROXIMATED.
05:50 UTCFUNNEL CLOUD2 Nnw LivingstonPolk, TXPUBLIC REPORTED A POSSIBLE FUNNEL CLOUD NNW OF LIVINGSTON ON FM-350. TIME APPROXIMATED.
06:15 UTCHAIL 0.52 Se LivingstonPolk, TXMARBLE HAIL REPORTED TO LAW ENFORCEMENT ON S.H. 146 2 MILES SOUTHEAST OF LIVINGSTON.
06:50 UTCTSTM WND DMG3 Sse LivingstonPolk, TXTREES DOWN ABOUT 3 MILES SOUTH-SOUTHEAST OF LIVINGSTON.
07:10 UTCTSTM WND DMGSegnoPolk, TXTREE DOWN ON A MOBILE HOME IN SEGNO.

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

This ground now

The live radar over the trackEvery 2011 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of April 25, 2011

45 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 259:05 AM CDTEF0Hempstead, AR7.6100
April 251:55 PM CDTEF0Hood, TX2.5150
April 252:00 PM CDTEF0Hood, TX0.425
April 252:02 PM CDTEF0McCurtain, OK9.275
April 252:55 PM CDTEF1Polk, AR5.850$250,000
April 253:00 PM CDTEF0Somervell, TX0.850
April 253:10 PM CDTEF0Johnson, TX2.6400
April 253:15 PM CDTEF0Johnson, TX0.9150
April 253:32 PM CDTEF1Cherokee, TX8.675$500
April 254:23 PM CDTEF0Hill, TX0.730
April 254:23 PM CDTEF1Christian, KY1.5275$100,000
April 254:24 PM CDTEF1Garland, AR9.3300$600,000
April 254:35 PM CDTEF1Pike, AR11.6800$290,000
April 254:56 PM CDTEF2Garland, AR5.92009$3.0 million
April 255:00 PM CDTEF1Pike, AR4.3300$200,000
April 255:02 PM CDTEF2Garland, AR14.430010$5.0 million
April 255:18 PM CDTEF0McCurtain, OK2.550$5,000
April 255:20 PM CDTEF0Ellis, TX0.550$25,000
April 255:37 PM CDTEF0Sevier, AR7.470
April 255:47 PM CDTEF1Wayne, MO11.8200$25,000
April 255:58 PM CDTEF1Wayne, MO5.9500$70,000
April 256:07 PM CDTEF3Garland, AR16.8300120$23 million
April 256:21 PM CDTEF1Perry, AR6.0300$700,000
April 256:29 PM CDTEF1Pike, AR4.2250$100,000
April 256:30 PM CDTEF1Bollinger, MO2.870$200,000
April 256:48 PM CDTEF1Pulaski, AR1.6400$250,000
April 256:48 PM CDTEF2Pulaski, AR51.32,900416$53 million
April 256:53 PM CDTEF0Limestone, TX1.3100
April 256:59 PM CDTEF0Freestone, TX0.8100
April 257:06 PM CDTEF1Faulkner, AR1.150$100,000
April 257:25 PM CDTEF0Freestone, TX3.5500
April 257:35 PM CDTEF0Leon, TX0.9100
April 257:46 PM CDTEF2Pulaski, AR5.23504$125 million
April 257:53 PM CDTEF1Lonoke, AR21.9800$390,000
April 258:15 PM CDTEF1Prairie, AR6.2100$25,000
April 258:24 PM CDTEF1White, AR8.9100$1.0 million
April 259:15 PM CDTEF1Houston, TX0.230$50,000
April 259:37 PM CDTEF1Angelina, TX7.7250$400,000
April 259:45 PM CDTEF1Trinity, TX0.6100$30,000
April 2510:13 PM CDTEF0Angelina, TX0.725$2,000
April 2511:45 PM CDTEF1Weakley, TN to KY15.4225$150,000
April 2511:47 PM CDTEF0Henderson, TN17.0200$20,000
April 2512:30 AM CDTEF0Calloway, KY0.8175$80,000
April 2512:37 AM CDTEF1Lyon, KY3.250$150,000
April 2512:40 AM CDTEF1Lyon, KY15.4100$200,000

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.