Tornadoes · United States · Oklahoma · 2007

EF1 tornado, Minco, Oklahoma, May 8, 2007

This EF1 tornado ran 1.5 miles across Grady County on May 8, 2007, touching down at 10:54 PM CDT and reaching 30 yards wide. It killed nobody, and did $70,000 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 mph

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

  2. EF186 to 110 mphthis tornado

    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
EF1
Date
May 8, 2007
Touchdown
10:54 PM CDT (03:54 UTC)
Lifted
10:58 PM CDT (03:58 UTC)
On the ground
4 minutes
Path length
1.5 miles (2.4 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
Property damage
$70,000
County
Grady County
Touchdown point
35.292, -97.964
Lift-off point
35.320, -97.976
Record number
0705082154-01

What the Weather Service recorded

An upper level storm system moved slowly east northeast through southeast Arizona and southwest New Mexico. A couple of disturbances rotated around the storm system and moved over the southern plains during the morning and afternoon hours. One disturbance moved over Oklahoma during the morning hours, with the other moving over Oklahoma during the evening hours. A stationary front remained located south of the Red River, with another front establishing itself over the southeast third of Oklahoma. Showers and thunderstorms developed and moved over the main body of Oklahoma during the morning hours. Widespread flash flooding was reported over central Oklahoma, with rivers rising out of their banks. After a lull in precipitation for a few hours the other disturbance moved over Oklahoma during the late afternoon and evening hours. Widespread showers and thunderstorms developed over southwest Oklahoma and continued to develop into central and southern Oklahoma. Large hail and severe wind gusts were reported, with flash flooding and river flooding continuing to be a concern due to the heavy rainfall earlier in the day. Supercell thunderstorms formed in southwest Oklahoma producing one tornado near Lake Ellsworth. As the showers and storms continued to develop and move northeast, a mesoscale convective vorticity maximum (MCV) developed. In the vicinity of this MCV, transient circulations on many scales were observed in the storm-relative radar velocity fields and in the storm motions themselves. Some of the circulations briefly tightened to tornado scale causing damage west of Minco, west of Union City, and in El Reno. Monetary damages were estimated.

Damage was first observed to dairy facility 2.7 miles southwest of Minco where the western portion of the south wall was pushed in which in turn pushed the roof and the northern wall of the building to the north. To the northwest, a farm sustained roof damage to the house, and damage to three metal storage buildings and two barns. Fences and trees were also damaged along the path. Monetary damages were estimated.

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.

Issued (UTC)ExpiredProductOffice
10:27 UTC17:00 UTCFlood WatchOUN
13:14 UTC16:15 UTCFlash Flood WarningOUN
22:30 UTC03:00 UTCTornado WatchOUN
03:12 UTC06:15 UTCFlash Flood WarningOUN
03:46 UTC04:30 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 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 00:35 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), 00:00Z

3.9 hours before the tornado, 53 km from the path. May 9, 2007.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2007-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 763 joules per kilogram, CIN -23, lifted condensation level 784 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 2007-05-09The 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 49 square meters per square second, 0 to 6 km bulk shear 21 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
763 J/kg
Mixed-layer CIN
-23 J/kg
Surface CAPE
1786 J/kg
Mixed-layer LCL
784 m above ground
0-6 km bulk shear
21 kt
0-1 km bulk shear
8 kt
0-1 km storm-relative helicity
49 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 12:00Z

8.1 hours after it, 53 km from the path. May 9, 2007.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2007-05-09Temperature 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 -84, lifted condensation level 991 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 2007-05-09The 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 105 square meters per square second, 0 to 6 km bulk shear 22 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
83 J/kg
Mixed-layer CIN
-84 J/kg
Surface CAPE
21 J/kg
Mixed-layer LCL
991 m above ground
0-6 km bulk shear
22 kt
0-1 km bulk shear
27 kt
0-1 km storm-relative helicity
105 m²/s²
0-3 km storm-relative helicity
127 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.9 K/km

Open this sounding in Storm Lab

The radar

The Norman radar (KTLX), 63 km away, was scanning. The volume nearest the touchdown began at 03:54 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
01:56 UTCTSTM WND GST 70ApacheCaddo, OKFROM APACHE FD
02:30 UTCFLASH FLOODApacheCaddo, OKSTREET FLOODING IN APACHE
04:45 UTCTORNADOEl RenoCanadian, OKAPPARENT TORNADO IN EL RENO. TORNADO CROSSED I-40 NEAR MM 126...OVERTURNING AT LEAST THREE 18 WHEELERS AND DAMAGING BILLBOARDS. SOME STRUCTURAL DAMAGE REPORTED IN EL RENO...ALONG WITH NUMEROUS TREES AND POWER LINES DOWN.
05:20 UTCTSTM WND GST 655 Wnw El RenoCanadian, OKNORTHWEST WIND OF 65 MPH MEASURED BY OKLAHOMA MESONET.
05:30 UTCTSTM WND GST 70PiedmontCanadian, OK

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 OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of May 8, 2007

8 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 84:11 PM CDTEF0Shackelford, TX6.550
May 85:30 PM CDTEF1Haskell, TX4.245$10,000
May 85:54 PM CDTEF0Throckmorton, TX0.840
May 88:15 PM CDTEF0Comanche, OK0.230
May 811:26 PM CDTEF0Canadian, OK2.240$100,000
May 811:43 PM CDTEF1Canadian, OK1.8150$3.0 million
May 812:08 AM CDTEF1Canadian, OK0.680
May 812:21 AM CDTEF1Canadian, OK0.230$25,000

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.