Tornadoes · United States · Missouri · 2001

F1 tornado, Pilot Grove, Missouri, April 10, 2001

This F1 tornado ran 5.0 miles across Cooper County on April 10, 2001, touching down at 6:11 PM CDT and reaching 50 yards wide. It killed nobody, and did $30,000 of property damage.

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 mph

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

  2. F173 to 112 mphthis tornado

    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
F1
Date
April 10, 2001
Touchdown
6:11 PM CDT (23:11 UTC)
Path length
5.0 miles (8.0 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$30,000
County
Cooper County
Touchdown point
38.870, -92.920
Lift-off point
38.870, -92.820
Record number
694

What the Weather Service recorded

Tornado on the ground around Pilot Grove for 5 minutes, moving east. It produced minor roof damage to two homes. There were also downed trees and power lines. It was accompanied by baseball sized hail.

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

The warnings

12 minutes of warning. NWS EAX issued a tornado warning for this county at 22:59 UTC, 12 minutes before the tornado touched down, in force until 00:00 UTC.

Issued (UTC)ExpiredProductOffice
05:51 UTC06:45 UTCSevere Thunderstorm WarningEAX
22:59 UTC00:00 UTCTornado WarningEAX
23:38 UTC01:30 UTCFlash Flood WarningEAX

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. The outlook in force was issued at 20:18 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.

Springfield, MO (KSGF), 12:00Z

11.2 hours before the tornado, 234 km from the path. April 10, 2001.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 2001-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1257 joules per kilogram, CIN -9, lifted condensation level 742 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, Springfield, MO at 12:00Z on 2001-04-10The 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 223 square meters per square second, 0 to 6 km bulk shear 47 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
1257 J/kg
Mixed-layer CIN
-9 J/kg
Surface CAPE
321 J/kg
Mixed-layer LCL
742 m above ground
0-6 km bulk shear
47 kt
0-1 km bulk shear
31 kt
0-1 km storm-relative helicity
223 m²/s²
0-3 km storm-relative helicity
243 m²/s²
Significant tornado parameter
1.5
Supercell composite
7.5
0-3 km lapse rate
5.1 K/km

Open this sounding in Storm Lab

Springfield, MO (KSGF), 00:00Z

0.8 hours after it, 234 km from the path. April 11, 2001.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 00:00Z on 2001-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1240 joules per kilogram, CIN -33, lifted condensation level 1315 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, Springfield, MO at 00:00Z on 2001-04-11The 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 164 square meters per square second, 0 to 6 km bulk shear 58 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
1240 J/kg
Mixed-layer CIN
-33 J/kg
Surface CAPE
1230 J/kg
Mixed-layer LCL
1315 m above ground
0-6 km bulk shear
58 kt
0-1 km bulk shear
20 kt
0-1 km storm-relative helicity
164 m²/s²
0-3 km storm-relative helicity
240 m²/s²
Significant tornado parameter
1.4
Supercell composite
6.7
0-3 km lapse rate
6.7 K/km

Open this sounding in Storm Lab

The surface observations

Sedalia (DMO), 32 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
21:53 UTC716790° 7 kt1004.4
22:43 UTC69.868100° 16 kt221000.3VCTS BR
22:53 UTC7068 6 kt1003
23:12 UTC71.666.2290° 19 kt271005.4VCTS
23:19 UTC6864.4270° 16 kt301005.4VCTS RA BR
23:22 UTC66.264.4290° 27 kt411005.4VCTS +RA BR
23:24 UTC66.264.4300° 25 kt411005.4VCTS +RA FG
23:27 UTC66.264.4300° 16 kt411005.4+RA FG
23:34 UTC66.264.4250° 7 kt271006.4-RA BR
23:53 UTC676350° 6 kt1006.1
00:53 UTC646360° 9 kt1005.8

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

The radar

The Pleasant Hill radar (KEAX), 121 km away, was scanning. The volume nearest the touchdown began at 23:11 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 2001 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

The other tornadoes of April 10, 2001

28 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 105:20 PM CDTF1Johnson, MO8.075$2.0 million
April 105:45 PM CDTF1Pettis, MO10.075$50,000
April 106:47 PM CDTF0Moniteau, MO0.125
April 107:20 PM CDTF1Callaway, MO3.010012$70,000
April 108:20 PM CDTF0Warren, MO0.150$20,000
April 108:30 PM CDTF0Saint Charles, MO4.050
April 108:45 PM CDTF1Saint Charles, MO1.0100$5.0 million
April 109:35 PM CDTF1Madison, IL2.01001$5.0 million
April 109:42 PM CDTF1Kearny, KS5.1150$150,000
April 1010:22 PM CDTF1Carson, TX1.5100$70,000
April 1011:06 PM CDTF2Hansford, TX4.02002$750,000
April 1011:08 PM CDTF2Trego, KS40.1400$750,000
April 1011:35 PM CDTF1Rooks, KS14.0300$100,000
April 1011:40 PM CDTF2Beaver, OK12.0200$450,000
April 1011:45 PM CDTF0Rooks, KS3.0751$100,000
April 1012:00 AM CDTF1Beaver, OK6.0100$250,000
April 1012:05 AM CDTF1Osborne, KS9.0100$150,000
April 1012:10 AM CDTF2Ford, KS17.3380$190,000
April 1012:10 AM CDTF0Beaver, OK2.050$100,000
April 1012:17 AM CDTF2Wheeler, TX6.0200$150,000
April 1012:24 AM CDTF1Smith, KS4.0100$70,000
April 1012:25 AM CDTF1Osborne, KS2.075$50,000
April 1012:25 AM CDTF1Osborne, KS13.0200$160,000
April 1012:39 AM CDTF2Ford, KS10.0200$420,000
April 1012:46 AM CDTF1Wichita, TX4.5100$150,000
April 1012:48 AM CDTF1Ford, KS9.6150$170,000
April 1012:49 AM CDTF0Smith, KS3.550$10,000
April 1012:57 AM CDTF0Edwards, KS7.4100

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.