Tornadoes · United States · Oklahoma · 2010
EF1 tornado, Hennepin to Sulphur, Oklahoma, May 19, 2010
From Hennepin to Sulphur, this EF1 tornado ran 17.5 miles across Garvin and Murray counties on May 19, 2010, touching down at 8:31 PM CDT and reaching 375 yards wide. It killed nobody.
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.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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 19, 2010
- Touchdown
- 8:31 PM CDT (01:31 UTC)
- Lifted
- 8:53 PM CDT (01:53 UTC)
- On the ground
- 22 minutes
- Path length
- 17.5 miles (28.2 km)
- Path width
- 375 yards (343 m)
- Deaths
- 0
- Injuries
- 0
- Counties
- Garvin and Murray counties
- Touchdown point
- 34.578, -97.268
- Lift-off point
- 34.626, -96.970
- Record number
- 1005191931-01
What the Weather Service recorded
A large storm system moved through the southern and central Plains during the morning and afternoon of the 19th. Thunderstorms, some of them severe, had developed over the Texas panhandle and moved east into northwest and north central Oklahoma during the early morning hours. Additional development, aided by the low-level jet, occurred into parts of central Oklahoma, north of a warm front that was slowly moving north to near Interstate 40. ||By mid afternoon, the well-defined front was located from parts of west-central into central Oklahoma, just north of the Oklahoma City metro area. Two thunderstorms developed near and along the front, one over Roger Mills and Dewey counties, and the other over northern Blaine county. The storms quickly became tornadic, with the first tornado of the day occurring north of Leedey in Dewey county. Another tornado, and probably the most photographed one of the day, occurred just north of Hennessey. Tornadoes, most of them brief in duration, and large hail continued across western and central Kingfisher county, and across northern Logan, southeast Garfield, and Payne counties. Another thunderstorm developed further east along the dry line later in the afternoon, and the storm eventually produced a tornado west of Prague in Lincoln county. ||Finally, two supercell thunderstorms developed further south along the dry line that moved into central Oklahoma. Although both showed significant rotation on radar, only the supercell that moved from Stephens through Murray counties produced tornadoes. Two tornadoes were reported, one just southeast of Wynnewood and another north of Sulphur.||Additional severe thunderstorms developed across southern Oklahoma, but the main impacts had shifted from tornadoes to large hail and very heavy rainfall. By the time it was all said and done, five main supercells had occurred over parts of western and central Oklahoma, producing at least nine tornadoes. Widespread significant damage did not occur due to the location/short duration of the tornadoes, and only three minor injuries were reported.
The tornado developed 7 miles west-southwest of Wynnewood in Garvin county, and continued into Murray county, where the bulk of the damage occurred. Minor tree damage occurred on the Garvin county side of the tornado. Monetary damage estimates were not available.
This is a continuation of the Garvin county tornado that began 7 miles west-southwest of Wynnewood. Structural damage was concentrated in and around the community of Joy, along Joy Rd. east of Hwy 77. Several barns and outbuildings were heavily damaged, and some homes had roof damage. Extensive tree and power pole/line damage was also noted. Further to the east-northeast a home lost part of its roof. Monetary damage estimates were not available.
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 tornado watch, issued at 19:10 UTC and running to 02:35 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 19:10 UTC | 02:35 UTC | Tornado Watch | OUN |
| 23:49 UTC | 00:45 UTC | Severe Thunderstorm Warning | OUN |
| 00:26 UTC | 01:15 UTC | Tornado Warning | OUN |
| 01:11 UTC | 02:15 UTC | Severe Thunderstorm Warning | OUN |
| 01:33 UTC | 02:15 UTC | Tornado Warning | OUN |
| 02:10 UTC | 02:42 UTC | Tornado Warning | OUN |
| 02:35 UTC | 07:00 UTC | Tornado Watch | OUN |
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 0.10 chance of a tornado within 25 miles, in the hatched area where significant tornadoes were expected. The outlook in force was issued at 01:00 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
1.5 hours before the tornado, 73 km from the path. May 20, 2010.
- Mixed-layer CAPE
- 1598 J/kg
- Mixed-layer CIN
- -6 J/kg
- Surface CAPE
- 2220 J/kg
- Mixed-layer LCL
- 954 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km bulk shear
- 30 kt
- 0-1 km storm-relative helicity
- 259 m²/s²
- 0-3 km storm-relative helicity
- 410 m²/s²
- Significant tornado parameter
- 2.8
- Supercell composite
- 18.7
- 0-3 km lapse rate
- 6.5 K/km
Norman, OK (KOUN), 12:00Z
10.5 hours after it, 73 km from the path. May 20, 2010.
- Mixed-layer CAPE
- 53 J/kg
- Mixed-layer CIN
- -374 J/kg
- Surface CAPE
- 253 J/kg
- Mixed-layer LCL
- 1010 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- -63 m²/s²
- 0-3 km storm-relative helicity
- 31 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.1 K/km
The surface observations
Pauls Valley Municipal Airport (PVJ), 15 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 23:48 UTC | 80.6 | 69.8 | 160° 12 kt | 1003 | ||
| 00:08 UTC | 80.6 | 68 | 160° 14 kt | 18 | 1002.4 | |
| 00:28 UTC | 80.6 | 68 | 160° 9 kt | 16 | 1003.4 | |
| 00:48 UTC | 80.6 | 69.8 | 160° 9 kt | 1003.4 | VCTS | |
| 01:08 UTC | 78.8 | 69.8 | 170° 6 kt | 1003.7 | VCTSRA | |
| 01:28 UTC | 77 | 71.6 | 230° 6 kt | 1004.7 | +VCTSRA | |
| 01:50 UTC | 71.6 | 66.2 | 140° 10 kt | 17 | 1004.4 | -TSRA |
| 02:08 UTC | 69.8 | 62.6 | 240° 4 kt | 14 | 1006.1 | +TSRA |
| 02:27 UTC | 69.8 | 62.6 | 0° 0 kt | 1004.4 | -VCTSRA | |
| 02:48 UTC | 69.8 | 64.4 | 210° 5 kt | 1004.4 | ||
| 03:08 UTC | 69.8 | 64.4 | 180° 4 kt | 1004.4 | ||
| 03:30 UTC | 69.8 | 64.4 | 170° 4 kt | 1004.7 |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Norman radar (KTLX), 83 km away, was scanning. The volume nearest the touchdown began at 01:29 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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 00:28 UTC | HAIL 1 | Slaughterville | Cleveland, OK | |
| 00:45 UTC | HAIL 2.5 | Slaughterville | Cleveland, OK | TIME ESTIMATED BY RADAR. |
| 00:50 UTC | HAIL 1 | Foster | Garvin, OK | |
| 01:00 UTC | HAIL 1.75 | Foster | Garvin, OK | |
| 01:10 UTC | HAIL 1 | 1 W Etowah | Cleveland, OK | |
| 01:10 UTC | HAIL 1.5 | 1 Sw Elmore City | Garvin, OK | |
| 01:31 UTC | TORNADO | 6 Nne Hennepin | Garvin, OK | |
| 01:36 UTC | HAIL 1.75 | 1 S Macomb | Pottawatomie, OK | |
| 01:40 UTC | HAIL 1.75 | 4 W St. Louis | Pottawatomie, OK | |
| 01:40 UTC | TORNADO | 4 W Wynnewood | Garvin, OK | MULTIVORTEX ON THE GROUND 7 TO 10 MINUTES WITH POWER FLASHES AND SOME TREE DAMAGE OF UNKNOWN EXTENT. |
| 01:52 UTC | TORNADO | 4 Sse Wynnewood | Murray, OK | DAMAGE TO BUILDINGS AND TREES ON EAST SIDE OF JOY. TIME ESTIMATED BY RADAR. |
| 02:16 UTC | HAIL 1.75 | 7 Wnw Roff | Garvin, OK | |
| 02:16 UTC | TORNADO | 8 N Sulphur | Murray, OK | BARN ROOF BLOWN OFF. RELAYED FROM ADA/PONTOTOC EOC. TIME ESTIMATED FROM RADAR. |
| 02:32 UTC | TSTM WND GST 70 | 2 W Roff | Pontotoc, OK | |
| 02:37 UTC | HAIL 1.75 | Roff | Pontotoc, OK | |
| 03:15 UTC | HAIL 1.75 | 9 Sw Ada | Pontotoc, OK | |
| 04:02 UTC | HAIL 0.88 | Tupelo | Coal, OK | RELAYED BY COAL COUNTY EM. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2010 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are
The other tornadoes of May 19, 2010
24 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| May 19 | 1:22 AM CDT | EF0 | Ellis, OK | 0.5 | 50 | |||
| May 19 | 1:56 AM CDT | EF1 | Hutchinson, TX | 0.4 | 100 | $28,000 | ||
| May 19 | 3:15 AM CDT | EF1 | Ellis, OK | 0.5 | 30 | |||
| May 19 | 3:32 AM CDT | EF0 | Ochiltree, TX | 1.1 | 50 | |||
| May 19 | 3:24 PM CDT | EF0 | Dewey, OK | 5.9 | 40 | |||
| May 19 | 4:41 PM CDT | EF0 | Kingfisher, OK | 0.1 | 50 | |||
| May 19 | 5:08 PM CDT | EF0 | Kingfisher, OK | 0.1 | 10 | |||
| May 19 | 5:24 PM CDT | EF0 | Logan, OK | 1.6 | 20 | |||
| May 19 | 5:33 PM CDT | EF1 | Kingfisher, OK | 14.0 | 75 | 1 | ||
| May 19 | 5:48 PM CDT | EF0 | Gray, KS | 0.1 | 30 | |||
| May 19 | 5:48 PM CDT | EF0 | Gray, KS | 0.2 | 30 | |||
| May 19 | 5:55 PM CDT | EF0 | Finney, KS | 0.4 | 50 | |||
| May 19 | 5:56 PM CDT | EF0 | Gray, KS | 0.5 | 50 | |||
| May 19 | 6:03 PM CDT | EF1 | Payne, OK | 10.6 | 200 | |||
| May 19 | 6:04 PM CDT | EF0 | Logan, OK | 0.1 | 10 | |||
| May 19 | 6:26 PM CDT | EF0 | Gray, KS | 0.3 | 30 | |||
| May 19 | 6:57 PM CDT | EF0 | Gray, KS | 0.2 | 30 | |||
| May 19 | 7:03 PM CDT | EF0 | Gray, KS | 0.4 | 50 | |||
| May 19 | 7:09 PM CDT | EF0 | Creek, OK | 0.1 | 50 | |||
| May 19 | 7:37 PM CDT | EF1 | Creek, OK | 5.0 | 600 | $15,000 | ||
| May 19 | 8:12 PM CDT | EF1 | Lincoln, OK | 1.4 | 25 | |||
| May 19 | 6:15 PM PDT | EF0 | Grant, WA | 0.2 | 100 | $2,000 | ||
| May 19 | 8:46 PM CDT | EF1 | Okfuskee, OK | 8.0 | 500 | |||
| May 19 | 9:05 PM CDT | EF1 | Okfuskee, OK | 10.0 | 500 | $15,000 |
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.