Tornadoes · United States · Texas · 2011

EF4 tornado, Tipton Arpt to Tipton, Texas, November 7, 2011

From Tipton Arpt to Tipton, this EF4 tornado ran 17.4 miles across Tillman, Wilbarger and Jackson counties on November 7, 2011, touching down at 2:38 PM CST and reaching 500 yards wide. It killed nobody.

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 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 mphthis tornado

    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
EF4
Date
November 7, 2011
Touchdown
2:38 PM CST (20:38 UTC)
Lifted
3:13 PM CST (21:13 UTC)
On the ground
35 minutes
Path length
17.4 miles (28.0 km)
Path width
500 yards (457 m)
Deaths
0
Injuries
0
Counties
Tillman, Wilbarger and Jackson counties
Touchdown point
34.330, -99.220
Lift-off point
34.542, -99.115
Record number
1111071438-01

What the Weather Service recorded

A powerful storm system moving through the southern Great Plains produced tornadoes, large hail, damaging winds and flooding across parts of Oklahoma and western north Texas on November 7-8, 2011.||The strong storm system generated severe weather including tornadoes, large hail, damaging winds and flooding from the early afternoon of November 7th through the early morning of November 8th. Several supercell thunderstorms developed over southwest Oklahoma during the mid-afternoon hours and moved northeast. One particularly nasty supercell thunderstorm developed over northern Wilbarger county in north Texas. This thunderstorm moved northeast into Tillman county, eventually producing at least eight tornadoes over a five county area. Two of the tornadoes moved near two Oklahoma Mesonet sites, both taking direct hits. The Mesonet site at Tipton measured 86.4 mph before it was destroyed. The Mesonet site near Fort Cobb measured 91.4 mph before it was destroyed. Both sites also recorded significant drops in surface pressure. Other supercells over southwest Oklahoma eventually congealed into a complex of storms and moved east into central Oklahoma. Numerous reports of high winds (92 mph near Clinton, OK) and hail up to golf ball-size were reported. The severe threat transitioned to a heavy rain and high threat after sunset.

This violent tornado continued northeast into Tillman county about 9 miles SSW of Tipton. The most severe damage occurred at the Oklahoma State University Agronomy Research Station. The buildings at the site were demolished, with most of the debris thrown into the nearby fields. The trees surrounding the site were debarked and splintered. Other damage was to the Tipton Mesonet site that took a direct hit. The wind speed maxed out at 86.4 mph before the site was demolished by flying debris. The tornado lifted about 3 miles NNE of Tipton.

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.

The county was under a tornado watch, issued at 19:11 UTC and running to 02:29 UTC.

Issued (UTC)ExpiredProductOffice
19:11 UTC02:29 UTCTornado WatchOUN
20:02 UTC21:00 UTCSevere Thunderstorm WarningOUN
23:32 UTC00:15 UTCSevere Thunderstorm WarningOUN
02:26 UTC03:30 UTCSevere Thunderstorm WarningOUN
02:29 UTC10:00 UTCTornado WatchOUN
02:44 UTC03:30 UTCSevere Thunderstorm WarningOUN

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 Slight Risk, with a 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 19:49 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.

Norman, OK (KOUN), 12:00Z

8.6 hours before the tornado, 183 km from the path. November 7, 2011.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2011-11-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1081 joules per kilogram, CIN -4, lifted condensation level 482 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, Norman, OK at 12:00Z on 2011-11-07The 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 201 square meters per square second, 0 to 6 km bulk shear 49 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
1081 J/kg
Mixed-layer CIN
-4 J/kg
Surface CAPE
572 J/kg
Mixed-layer LCL
482 m above ground
0-6 km bulk shear
49 kt
0-1 km bulk shear
24 kt
0-1 km storm-relative helicity
201 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
0.9
Supercell composite
4.1
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 00:00Z

3.4 hours after it, 183 km from the path. November 8, 2011.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2011-11-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1647 joules per kilogram, CIN -1, lifted condensation level 574 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, Norman, OK at 00:00Z on 2011-11-08The 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 316 square meters per square second, 0 to 6 km bulk shear 44 knots.1939587897Sfc1 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
1647 J/kg
Mixed-layer CIN
-1 J/kg
Surface CAPE
1517 J/kg
Mixed-layer LCL
574 m above ground
0-6 km bulk shear
44 kt
0-1 km bulk shear
33 kt
0-1 km storm-relative helicity
316 m²/s²
0-3 km storm-relative helicity
325 m²/s²
Significant tornado parameter
3.0
Supercell composite
12.9
0-3 km lapse rate
5.8 K/km

Open this sounding in Storm Lab

The surface observations

Frederick (FDR), 19 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:53 UTC7365160° 19 kt241009.1
20:01 UTC73.464.4160° 15 kt231008.8
20:36 UTC73.464.4140° 17 kt1008.1VCTS
20:51 UTC75.264.4150° 22 kt291007.8VCTS
20:53 UTC7565150° 23 kt291007.8VCTS

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

The radar

The Altus AFB radar (KFDR), 19 km away, was scanning. The volume nearest the touchdown began at 20:38 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
20:54 UTCTORNADO 23 S TiptonTillman, OKTHIS LONG-LIVED TORNADO WAS OBSERVED PASSING TO THE SOUTH AND EAST OF TIPTON. IT LIKELY DEVELOPED IN EXTREME NORTHERN WILBARGER COUNTY TEXAS ABOUT 4 MILES EAST-NORTHEAST OF FARGO TEXAS AT AROUND 238 PM CST, AND DISSIPATE
20:54 UTCTORNADO3 S TiptonTillman, OK
21:15 UTCTORNADO2 Nw ManitouTillman, OKA TORNADO DEVELOPED TO THE WEST OR NORTHWEST OF MANITOU AT APPROXIMATELY 315 PM CST.. MOVED NORTHEAST AND DISSIPATED NEAR US HIGHWAY 183 LIKELY JUST NORTH OF THE KIOWA/TILLMAN COUNTY LINE SOUTH OF SNYDER.
21:20 UTCHAIL 1.25LugertKiowa, OK
21:25 UTCTSTM WND GST 7010 S SnyderTillman, OK
21:38 UTCTORNADO3 E SnyderKiowa, OK
21:50 UTCHAIL 21 N SnyderKiowa, OK
21:50 UTCTORNADO6 Ene Mountain ParkKiowa, OKA TORNADO DEVELOPED SOUTHEAST OF THE INTERSECTION OF STATE HIGHWAYS 49 AND 54 IN SOUTHEASTERN KIOWA COUNTY. THIS TORNADO MOVED NORTHEAST THROUGH THE WICHITA MOUNTAINS WILDLIFE REFUGE IN NORTHWESTERN COMANCHE COUNTY.. THE

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 November 7, 2011

9 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
November 72:59 PM CSTEF0Tillman, OK0.575
November 73:15 PM CSTEF0Tillman, OK6.0400
November 73:38 PM CSTEF0Kiowa, OK0.5100
November 73:52 PM CSTEF0Kiowa, OK13.4500
November 74:19 PM CSTEF0Kiowa, OK1.4100
November 74:24 PM CSTEF0Kiowa, OK0.5100
November 74:40 PM CSTEF0Caddo, OK3.0150
November 74:51 PM CSTEF1Caddo, OK13.0400
November 710:47 PM CSTEF1McClain, OK1.6110

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.