Tornadoes · United States · Texas · 2002

F0 tornado, Masterson, Texas, May 11, 2002

This F0 tornado ran 0.1 miles across Moore County on May 11, 2002, touching down at 1:51 AM CDT and reaching 25 yards wide. It killed nobody.

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 mphthis tornado

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

  2. F173 to 112 mph

    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
F0
Date
May 11, 2002
Touchdown
1:51 AM CDT (06:51 UTC)
Path length
0.1 miles (0.2 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
Moore County
Touchdown point
35.630, -101.980
Lift-off point
35.630, -101.980
Record number
113

What the Weather Service recorded

Severe thunderstorms struck during the early morning hours across the western and northern Texas panhandle producing large hail...high winds...and an isolated tornado.

The tornado occurred over open country and no damage was reported. A couple of trees were reported to be knocked over along with downed powerlines. The tornado path length and width were estimated.

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

The warnings

1 minute of warning. NWS AMA issued a tornado warning for this county at 06:50 UTC, 1 minute before the tornado touched down, in force until 07:30 UTC.

Issued (UTC)ExpiredProductOffice
06:22 UTC07:15 UTCSevere Thunderstorm WarningAMA
06:50 UTC07:30 UTCTornado WarningAMA

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.

What forecasters said that day

The local office's own words before the tornado touched down, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Amarillo, TX wrote its last area forecast discussion before the tornado touched down at May 10, 4:02 PM CDT, 9 hours 49 minutes earlier.

Area forecast discussion, May 10, 4:02 PM CDT, 9 hours 49 minutes before
TEXAS/OKLAHOMA PANHANDLES FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AMARILLO TX
315 PM CDT FRI MAY 10 2002

WMFNT FEATURE IS ABT TO ENTER SWRN CORNER OF FCST AREA ATTM.  MDT
LOW-LVL FLOW HAS REPLENISHED MSTR INTO UPR 40S TO MID 50S IN ALL BUT
NWRN CORNER OF FCST AREA.  DVLPG DRYLN EXPCD TO ENTER W-CNTRL ZNS
BFR SS.  100KT JET AT H2 WL ENTER WRN ZNS THIS EVE...AND H5 50 KT
JET WL ARRIVE IN NWRN ZNS BFR SS.  DEEP CNVGNC SEEN IN CLR AIR OVR
NERN NM AND SERN CO.  EXPC THAT TSTMS WL DVLP ALG DRYLN AND WMFNT
THIS EVE...AND SVR POTENTIAL WL EXIST...SPLY DUE TO SHEARED AMS.
WL CALL FOR SCT TSTMS 1ST PD.  SERN ZNS WL HAVE TO OVERCOME DEEP
DVGNC INITIALLY.

HAVE REMOVED POPS FM WRN ZNS FOR SAT...AS SWLY SFC WNDS EXPCD TO
MIX DRYLN EWD.  HAVE RETAINED SLGT CHC ELSEWHERE.  ON SAT NGT...
CDFNT EXPCD TO ARRIVE IN NRN ZNS BFR 05Z...AND CLR SERN SXNS BFR SR.
WITH STG DYNAMICS AND POOLING OF LOW-LVL MSTR BHND FNT...HAVE KEPT
CHC TSTMS ALL ZONES.  WNDY CONDS WITH FROPA WL ENHANCE CNVGNC.

COOLER CONDS ON SUN WITH UPSLP COMPONENT TO LOW-LVL FLOW...AND LOW
POPS RETAINED.  DRY AMS IN PLACE SUN NGT THRU MON NGT.  CHC TSTMS
TUE THRU FRI AS MSTR RTRNS.  03

.AMA...
OK...NONE.
TX...NONE.

COCKRELL

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.

Amarillo Airport, TX (KAMA), 00:00Z

6.9 hours before the tornado, 51 km from the path. May 11, 2002.

Skew-T log-pSkew-T log-p diagram, Amarillo Airport, TX at 00:00Z on 2002-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 83 joules per kilogram, CIN -459, lifted condensation level 915 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, Amarillo Airport, TX at 00:00Z on 2002-05-11The 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 149 square meters per square second, 0 to 6 km bulk shear 56 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
83 J/kg
Mixed-layer CIN
-459 J/kg
Surface CAPE
15 J/kg
Mixed-layer LCL
915 m above ground
0-6 km bulk shear
56 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
149 m²/s²
0-3 km storm-relative helicity
250 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

Amarillo Airport, TX (KAMA), 12:00Z

5.1 hours after it, 51 km from the path. May 11, 2002.

Skew-T log-pSkew-T log-p diagram, Amarillo Airport, TX at 12:00Z on 2002-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1443 joules per kilogram, CIN -196, lifted condensation level 866 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, Amarillo Airport, TX at 12:00Z on 2002-05-11The 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 246 square meters per square second, 0 to 6 km bulk shear 43 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
1443 J/kg
Mixed-layer CIN
-196 J/kg
Surface CAPE
533 J/kg
Mixed-layer LCL
866 m above ground
0-6 km bulk shear
43 kt
0-1 km bulk shear
32 kt
0-1 km storm-relative helicity
246 m²/s²
0-3 km storm-relative helicity
225 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.4
0-3 km lapse rate
4.4 K/km

Open this sounding in Storm Lab

The surface observations

Amarillo - Rick Husband Intl (AMA), 52 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
04:53 UTC6361160° 18 kt241011.2
05:00 UTC62.660.8160° 19 kt221011.2
05:53 UTC6259170° 20 kt251010.5
06:53 UTC6560160° 17 kt1011.2
07:53 UTC6359170° 15 kt1010.8

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

The radar

The Amarillo radar (KAMA), 50 km away, was scanning. The volume nearest the touchdown began at 06:51 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.

This ground now

The live radar over the trackEvery 2002 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of May 11, 2002

16 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 114:14 PM CDTF0Barton, KS1.0110
May 114:20 PM CDTF0Barton, KS2.0220
May 114:27 PM CDTF0Lincoln, KS1.0110
May 114:27 PM CDTF0Lincoln, KS0.5110
May 114:34 PM CDTF0Ellsworth, KS1.0110
May 114:44 PM CDTF0Edwards, KS0.330
May 114:52 PM CDTF0Saline, KS1.0110
May 114:56 PM CDTF0Rice, KS0.5110
May 115:56 PM CDTF0Kiowa, KS0.350
May 116:12 PM CDTF0Stafford, KS0.350
May 116:13 PM CDTF0Stafford, KS0.550
May 116:15 PM CDTF0Pratt, KS0.330
May 116:25 PM CDTF0Reno, KS0.5110
May 116:25 PM CDTF0Reno, KS0.555
May 116:30 PM CDTF0Pratt, KS1.250
May 118:10 PM CDTF0Comanche, KS2.2100

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.