Tornadoes · United States · Oklahoma · 2007

EF1 tornado, Warner, Oklahoma, July 9, 2007

This EF1 tornado ran 0.3 miles across Muskogee County on July 9, 2007, touching down at 4:15 PM CDT and reaching 50 yards wide. It killed nobody, and did $100,000 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
July 9, 2007
Touchdown
4:15 PM CDT (21:15 UTC)
Lifted
4:17 PM CDT (21:17 UTC)
On the ground
2 minutes
Path length
0.3 miles (0.4 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$100,000
County
Muskogee County
Touchdown point
35.500, -95.247
Lift-off point
35.500, -95.247
Record number
0707091515-01

What the Weather Service recorded

Severe thunderstorms occurred from the late afternoon hours into the evening hours. Most reports were due to wind, but the most notable report was a tornado near Warner in Muskogee County.

A tornado removed a large section of the roof of a church, destroyed a tin storage barn, damaged two homes and snapped a couple of power poles and large trees limbs.

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
21:18 UTC22:15 UTCSevere Thunderstorm WarningTSA
21:36 UTC02:18 UTCSevere Thunderstorm WatchTSA
21:57 UTC23:00 UTCSevere Thunderstorm WarningTSA
04:19 UTC20:07 UTCFlash Flood WatchTSA

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 22:05 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

9.3 hours before the tornado, 198 km from the path. July 9, 2007.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2007-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2056 joules per kilogram, CIN -55, lifted condensation level 795 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, Norman, OK at 12:00Z on 2007-07-09The 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 35 square meters per square second, 0 to 6 km bulk shear 10 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
2056 J/kg
Mixed-layer CIN
-55 J/kg
Surface CAPE
1997 J/kg
Mixed-layer LCL
795 m above ground
0-6 km bulk shear
10 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
126 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.4 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 00:00Z

2.7 hours after it, 198 km from the path. July 10, 2007.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2007-07-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 3020 joules per kilogram, CIN -7, lifted condensation level 1274 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, Norman, OK at 00:00Z on 2007-07-10The 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 56 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
3020 J/kg
Mixed-layer CIN
-7 J/kg
Surface CAPE
4513 J/kg
Mixed-layer LCL
1274 m above ground
0-6 km bulk shear
21 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
101 m²/s²
Significant tornado parameter
0.8
Supercell composite
7.9
0-3 km lapse rate
7.1 K/km

Open this sounding in Storm Lab

The surface observations

Muskogee/Davis Field (MKO), 20 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:53 UTC8974170° 6 kt1011.5
20:53 UTC8877110° 14 kt191010.8
21:22 UTC84.275.2110° 10 kt1009.8VCTS
21:53 UTC7567240° 21 kt261011.9TS
22:00 UTC71.666.2230° 24 kt301011.9TSRA
22:02 UTC71.666.2230° 22 kt301012.2+TSRA BR
22:05 UTC71.666.2230° 15 kt301012.5+TSRA BR
22:09 UTC69.866.2230° 15 kt301012.9+TSRA BR
22:16 UTC71.666.2250° 13 kt221012.5VCTS BR
22:23 UTC71.666.2250° 15 kt1012.9+TSRA BR
22:32 UTC71.666.2250° 12 kt1012.2+TSRA BR
22:39 UTC71.668260° 12 kt1012.2TSRA BR
22:48 UTC71.668230° 6 kt1012.5-TSRA BR
22:53 UTC7368200° 5 kt1012.9-TSRA
23:03 UTC71.669.8190° 6 kt1012.5VCTS

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

The radar

The Tulsa radar (KINX), 80 km away, was scanning. The volume nearest the touchdown began at 21:14 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
21:15 UTCTORNADO3 E WarnerMuskogee, OKA TORNADO REMOVED A LARGE SECTION OF THE ROOF OF A CHURCH...DESTROYED A TIN STORAGE BARN...DAMAGED TWO HOMES...AND SNAPPED A COUPLE POWER POLES AND LARGE TREE LIMBS. THE TORNADO HAD AN ESTIMATED PATH LENGTH OF ABOUT 1/4
21:40 UTCTSTM WND DMG2 E WarnerMuskogee, OKROOF BLOWN OFF OF A CHURCH. SEVERAL HOUSES, TREES, AND AN OUTBUILDING DAMAGED. POSSIBLE TORNADO.
22:05 UTCHAIL 11 Nw StidhamMcintosh, OK
22:20 UTCTSTM WND DMGEufaulaMcintosh, OKROOF BLOWN OFF OF AN OFFICE BUILDING AT MAIN AND OAK.

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 July 9, 2007

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
July 94:15 PM EDTEF0Arenac, MI0.580$15,000
July 97:25 PM CDTEF1McLean, ND1.5604$80,000

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.