Tornadoes · United States · Missouri · 2007

EF0 tornado, Dillon, Missouri, August 24, 2007

This EF0 tornado ran 1.0 miles across Phelps County on August 24, 2007, touching down at 2:50 PM CDT and reaching 75 yards wide. It killed nobody, and did $10,000 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
August 24, 2007
Touchdown
2:50 PM CDT (19:50 UTC)
Lifted
2:51 PM CDT (19:51 UTC)
On the ground
1 minutes
Path length
1.0 miles (1.6 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
0
Property damage
$10,000
County
Phelps County
Touchdown point
37.970, -91.720
Lift-off point
37.970, -91.720
Record number
0708241350-01

What the Weather Service recorded

A short wave trough interacted with a moist and unstable airmass over the Missouri Ozarks that resulted in several strong to severe thunderstorms. Mainly wind damaged occurred, however, two tornadoes also touched down in Dent and Phelps counties.

A National Weather Service storm survey revealed that an EF-0 tornado briefly touched down in the community of Dillon. The tornado caused tree and structural damage to a business called BCI.

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. One was issued for the county at another hour that day.

The county was under a severe thunderstorm watch, issued at 17:20 UTC and running to 00:42 UTC.

Issued (UTC)ExpiredProductOffice
17:20 UTC00:42 UTCSevere Thunderstorm WatchSGF
19:28 UTC20:30 UTCSevere Thunderstorm WarningSGF
19:52 UTC20:15 UTCTornado WarningSGF
20:39 UTC21:18 UTCSevere Thunderstorm WarningSGF
21:00 UTC08:55 UTCFlash Flood WatchSGF

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 16:14 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

7.8 hours before the tornado, 219 km from the path. August 24, 2007.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 2007-08-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1334 joules per kilogram, CIN -50, lifted condensation level 948 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 2007-08-24The 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 27 square meters per square second, 0 to 6 km bulk shear 38 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
1334 J/kg
Mixed-layer CIN
-50 J/kg
Surface CAPE
396 J/kg
Mixed-layer LCL
948 m above ground
0-6 km bulk shear
38 kt
0-1 km bulk shear
7 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.4
Supercell composite
2.3
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

Springfield, MO (KSGF), 00:00Z

4.2 hours after it, 219 km from the path. August 25, 2007.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 00:00Z on 2007-08-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 491 joules per kilogram, CIN -79, lifted condensation level 975 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 2007-08-25The 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 33 square meters per square second, 0 to 6 km bulk shear 35 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
491 J/kg
Mixed-layer CIN
-79 J/kg
Surface CAPE
511 J/kg
Mixed-layer LCL
975 m above ground
0-6 km bulk shear
35 kt
0-1 km bulk shear
12 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
98 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.4
0-3 km lapse rate
5.6 K/km

Open this sounding in Storm Lab

The radar

The St Louis radar (KLSX), 121 km away, was scanning. The volume nearest the touchdown began at 19:48 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
18:58 UTCTSTM WND DMGSt. JamesPhelps, MOA LARGE SHED DESTROYED AND SEVERAL CARS DAMAGED.
19:34 UTCHAIL 1DoolittlePhelps, MO
19:42 UTCHAIL 0.75RollaPhelps, MOREPORTED AT MILE MARKER 184 ON I-44.
19:50 UTCTORNADO4 E RollaPhelps, MOA NATIONAL WEATHER SERVICE STORM SURVEY REVEALED THAT A WEAK EF-0 TORNADO TOUCHED DOWN NEAR THE COMMUNITY OF DILLON...OR FOUR MILES EAST OF ROLLA. THE TORNADO WAS 75 YARDS WIDE AND WAS ON THE GROUND FOR ABOUT ONE MILE. T
19:58 UTCTSTM WND DMGSt. JamesPhelps, MOA LARGE SHED DESTROYED AND SEVERAL CARS DAMAGED.
21:15 UTCTORNADO8 Nnw SalemDent, MOA WEAK EF-0 TORNADO TOUCHED DOWN IN RURAL DENT COUNTY APPROXIMATELY 8 MILES NORTH NORTHWEST OF SALEM. THE TORNADO WAS 50 YARDS WIDE WITH A PATH OF NEAR ONE TENTH OF A MILE. LITTLE DAMAGE OCCURED.
21:25 UTCTSTM WND DMGLickingTexas, MOTREES DOWN ALONG SHAFFER ROAD IN TOWN.

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

This ground now

The live radar over the trackEvery 2007 tornado in MissouriEvery tornado in Missouri since 1950Warnings in force in Missouri nowThe forecast where you are

The other tornadoes of August 24, 2007

9 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 244:25 PM EDTEF3Eaton, MI6.53005$40 million
August 244:55 PM EDTEF1Ingham, MI6.0300$300,000
August 244:15 PM CDTEF0Dent, MO0.125
August 245:23 PM EDTEF0Shiawassee, MI0.350$50,000
August 245:30 PM EDTEF2Livingston, MI23.54401$24 million
August 244:31 PM CDTEF0Brown, KS0.125
August 244:32 PM CDTEF0Atchison, KS0.125
August 246:02 PM EDTEF0Washtenaw, MI2.550$500,000
August 246:16 PM EDTEF1Lapeer, MI3.2250$1.0 million

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.