Tornadoes · United States · Oklahoma · 2015

EF0 tornado, Hydro, Oklahoma, May 26, 2015

This EF0 tornado ran 0.1 miles across Caddo County on May 26, 2015, touching down at 6:32 PM CDT and reaching 30 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.

  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
May 26, 2015
Touchdown
6:32 PM CDT (23:32 UTC)
Path length
0.1 miles (0.2 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
County
Caddo County
Touchdown point
35.522, -98.621
Lift-off point
35.522, -98.621
Record number
1505261732-02

What the Weather Service recorded

Supercell storms formed along a cold front and a dryline across western Oklahoma down through central Texas and then made their way eastward.

OKC television stations showed footage of a tornado developing briefly to the east of Weatherford and west-southwest of Hydro. A well house was thrown across the road, a heavy cattle feeder was displaced and a picnic table and gas grill were blown off a patio at a house on the Custer-Caddo County line. This tornado moved into Caddo County from Custer County.

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

The warnings

9 minutes of warning. NWS OUN issued a tornado warning for this county at 23:23 UTC, 9 minutes before the tornado touched down, in force until 00:00 UTC.

The county was under a severe thunderstorm watch, issued at 22:27 UTC and running to 05:11 UTC.

Issued (UTC)ExpiredProductOffice
09:29 UTC14:18 UTCDense Fog AdvisoryOUN
22:26 UTC23:15 UTCSevere Thunderstorm WarningOUN
22:27 UTC05:11 UTCSevere Thunderstorm WatchOUN
23:04 UTC23:45 UTCSevere Thunderstorm WarningOUN
23:23 UTC00:00 UTCTornado WarningOUN
23:43 UTC00:30 UTCSevere Thunderstorm WarningOUN
01:22 UTC02:15 UTCSevere Thunderstorm WarningOUN
01:55 UTC02:44 UTCSevere Thunderstorm WarningOUN
02:05 UTC03:00 UTCFlood AdvisoryOUN
02:07 UTC02:45 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 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 19:32 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

11.5 hours before the tornado, 116 km from the path. May 26, 2015.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2015-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -81536, lifted condensation level 1086 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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 2015-05-26The 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 37 square meters per square second, 0 to 6 km bulk shear 33 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
0 J/kg
Mixed-layer CIN
-81536 J/kg
Surface CAPE
4 J/kg
Mixed-layer LCL
1086 m above ground
0-6 km bulk shear
33 kt
0-1 km bulk shear
6 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.0 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 00:00Z

0.5 hours after it, 116 km from the path. May 27, 2015.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2015-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2696 joules per kilogram, CIN -28, lifted condensation level 836 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 2015-05-27The 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 71 square meters per square second, 0 to 6 km bulk shear 32 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
2696 J/kg
Mixed-layer CIN
-28 J/kg
Surface CAPE
4900 J/kg
Mixed-layer LCL
836 m above ground
0-6 km bulk shear
32 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
62 m²/s²
Significant tornado parameter
0.8
Supercell composite
6.7
0-3 km lapse rate
6.8 K/km

Open this sounding in Storm Lab

The surface observations

Weatherford (OJA), 5 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
21:35 UTC80.662.6170° 9 kt171012.9
21:55 UTC78.864.4170° 5 kt1012.9
22:15 UTC7766.2150° 8 kt1012.5
22:35 UTC78.868140° 11 kt1012.2
22:55 UTC7768140° 9 kt1011.9
23:15 UTC73.469.8150° 10 kt201011.5+RA
23:35 UTC73.466.2110° 9 kt161012.2-TSRA
23:55 UTC71.666.2230° 8 kt141012.5TS
00:15 UTC71.662.6150° 14 kt171012.9
00:35 UTC69.862.6140° 6 kt161013.2
00:55 UTC69.862.6160° 5 kt1013.2
01:15 UTC69.866.2160° 6 kt1013.5

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

The radar

The Norman radar (KTLX), 124 km away, was scanning. The volume nearest the touchdown began at 23:32 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
22:50 UTCHAIL 22 S Mountain ViewKiowa, OK
23:15 UTCHAIL 1.754 E WeatherfordCuster, OKDELAYED ENTRY. REPORTED ALONG INTERSTATE 40 EAST OF WEATHERFORD. TIME ESTIMATED FROM RADAR.
23:32 UTCTORNADO3 Sw HydroCaddo, OK
23:50 UTCHAIL 1.751 S HydroCaddo, OK
01:59 UTCHAIL 1.25CarnegieCaddo, OK
02:00 UTCHAIL 1.753 Sse CantonBlaine, OKDELAYED REPORT. TIME ESTIMATED FROM RADAR.
02:00 UTCHAIL 2.52 W CarnegieKiowa, OK
02:10 UTCHAIL 12 N CarnegieCaddo, OK
02:22 UTCTSTM WND GST 7010 W GreenfieldBlaine, OKTWO 12-INCH DIAMETER TREES DOWN

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

This ground now

The live radar over the trackEvery 2015 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of May 26, 2015

12 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 261:22 AM CDTEF1Jefferson Parish, LA0.4100
May 269:59 AM CDTEF1Henry, IL4.050$10,000
May 269:59 AM CDTEF1Jackson, IA0.125
May 2610:46 AM CDTEF1Bureau, IL2.450$15,000
May 2612:23 PM CDTEF0Green, WI0.120
May 261:08 PM CDTEF0Cook, IL0.450$10,000
May 263:41 PM EDTEF1Meriwether, GA9.8350$100,000
May 265:16 PM EDTEF1Greene, OH0.6702$750,000
May 265:40 PM CDTEF0Palo Pinto, TX2.275
May 266:06 PM CDTEF0Palo Pinto, TX0.560
May 266:29 PM CDTEF0Palo Pinto, TX0.680
May 266:32 PM CDTEF0Custer, OK0.130

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.