Tornadoes · United States · Oklahoma · 2017

Unrated tornado, Ringwood, Oklahoma, April 16, 2017

This Unrated tornado ran 0.1 miles across Major County on April 16, 2017, touching down at 7:09 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 mph

    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. Unratedthis tornado

    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
Unrated
Date
April 16, 2017
Touchdown
7:09 PM CDT (00:09 UTC)
Path length
0.1 miles (0.2 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
County
Major County
Touchdown point
36.319, -98.290
Lift-off point
36.319, -98.290
Record number
1704161809-01

What the Weather Service recorded

Scattered showers and thunderstorms formed out ahead of and along a front across Oklahoma on the evening of the 16th overnight into the 17th.

A KOCO (TV) storm chaser observed a tornado just east of US-281 near county road EW-48. No known damage occurred.

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 23:31 UTC and running to 02:41 UTC.

Issued (UTC)ExpiredProductOffice
23:31 UTC02:41 UTCSevere Thunderstorm WatchOUN
23:43 UTC00:30 UTCSevere Thunderstorm WarningOUN
00:12 UTC00:45 UTCTornado WarningOUN
00:41 UTC01:15 UTCTornado WarningOUN
01:11 UTC02:00 UTCSevere Thunderstorm WarningOUN
01:49 UTC02:30 UTCSevere Thunderstorm WarningOUN
02:04 UTC05:00 UTCFlood AdvisoryOUN
02:27 UTC03:15 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. The outlook in force was issued at 19:31 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

0.2 hours before the tornado, 146 km from the path. April 17, 2017.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 00:00Z on 2017-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1796 joules per kilogram, CIN -33, lifted condensation level 690 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 2017-04-17The 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 30 square meters per square second, 0 to 6 km bulk shear 24 knots.19395878Sfc1 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
1796 J/kg
Mixed-layer CIN
-33 J/kg
Surface CAPE
2302 J/kg
Mixed-layer LCL
690 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.1
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

Norman, OK (KOUN), 12:00Z

11.8 hours after it, 146 km from the path. April 17, 2017.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2017-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 627 joules per kilogram, CIN -59, lifted condensation level 728 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 2017-04-17The 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 122 square meters per square second, 0 to 6 km bulk shear 24 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
627 J/kg
Mixed-layer CIN
-59 J/kg
Surface CAPE
821 J/kg
Mixed-layer LCL
728 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
21 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
24 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.0
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

The radar

The Vance AFB radar (KVNX), 49 km away, was scanning. The volume nearest the touchdown began at 00:11 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
23:43 UTCTORNADO10 N ChesterMajor, OKKOCO CHASER DOCUMENTED A TORNADO ABOUT 5 MILES SOUTHWEST OF BOUSE JUNCTION. THE TORNADO MOVED SLOWLY SOUTH OR SOUTHWEST THROUGH 647 PM. NO KNOWN DAMAGE OCCURRED.
00:09 UTCTORNADO7 N ChesterMajor, OKKOCO CHASED DOCUMENTED A BRIEF TORNADO JUST EAST OF US-281. NO KNOWN DAMAGE OCCURRED.
00:42 UTCTORNADO4 Nnw ChesterMajor, OKKOCO CHASER DOCUMENTED A TORNADO NORTH-NORTHWEST OF CHESTER FROM 742 PM TO 749 PM. THE TORNADO IS ESTIMATED TO HAVE MOVED SOUTHWEST FROM ABOUT 4.5 MILES NORTH-NORTHWEST OF CHESTER. NO KNOWN DAMAGE OCCURRED.
02:03 UTCHAIL 1SeilingDewey, OK
02:27 UTCHAIL 11 Se SeilingDewey, OK

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

This ground now

The live radar over the trackEvery 2017 tornado in OklahomaEvery tornado in Oklahoma since 1950Warnings in force in Oklahoma nowThe forecast where you are

The other tornadoes of April 16, 2017

2 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 166:43 PM CDTUnratedMajor, OK0.530
April 167:42 PM CDTUnratedMajor, OK2.030

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.