Alert archive / Oklahoma / Tornado Watches in 2015

Tornado Watch 133

May 6, 201535 counties in Oklahoma; 22 counties in Texas

The Storm Prediction Center issued this tornado watch at May 6, 2015, 1:23 PM CDT for 35 counties in Oklahoma; 22 counties in Texas. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
May 6, 2015, 1:23 PM CDT (18:23 UTC)
Expired
May 6, 2015, 9:00 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt
All 57 counties

Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grady County, OK, Grant County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Jackson County, OK, Jefferson County, OK, Kay County, OK, Kingfisher County, OK, Kiowa County, OK, Lincoln County, OK, Logan County, OK, Major County, OK, McClain County, OK, Noble County, OK, Oklahoma County, OK, Pottawatomie County, OK, Roger Mills County, OK, Stephens County, OK, Tillman County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Archer County, TX, Baylor County, TX, Callahan County, TX, Clay County, TX, Eastland County, TX, Foard County, TX, Hardeman County, TX, Haskell County, TX, Jack County, TX, Jones County, TX, Knox County, TX, Montague County, TX, Palo Pinto County, TX, Parker County, TX, Shackelford County, TX, Stephens County, TX, Taylor County, TX, Throckmorton County, TX, Wichita County, TX, Wilbarger County, TX, Wise County, TX, Young County, TX

The radar

The Altus AFB radar (KFDR), 16 km from the middle of the area, began a volume at 18:23 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
50%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
70%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
90%
One or more hailstones of 2 inches or more
40%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

87 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 6, 2:11 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche49 min
May 6, 2:45 PM CDTTornado WarningOUNCaddo30 min
May 6, 3:03 PM CDTSevere Thunderstorm WarningOUNBlaine, Major42 min
May 6, 3:10 PM CDTTornado WarningOUNCaddo, Grady35 min
May 6, 3:43 PM CDTTornado WarningOUNGrady32 min
May 6, 3:45 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Blaine, Garfield, Grant, Major45 min
May 6, 4:03 PM CDTTornado WarningOUNAlfalfa, Garfield, Grant, Major27 min
May 6, 4:12 PM CDTTornado WarningOUNGrady33 min
May 6, 4:17 PM CDTSevere Thunderstorm WarningSJTHaskell28 min
May 6, 4:22 PM CDTSevere Thunderstorm WarningSJTCallahan, Coleman, Taylor38 min
May 6, 4:27 PM CDTTornado WarningOUNMajor33 min
May 6, 4:35 PM CDTSevere Thunderstorm WarningOUNKnox40 min
May 6, 4:41 PM CDTSevere Thunderstorm WarningSJTCallahan, Shackelford64 min
May 6, 4:43 PM CDTTornado Warning EmergencyOUNGrady, McClain47 min
May 6, 4:48 PM CDTSevere Thunderstorm WarningOUNCuster, Dewey42 min
May 6, 4:52 PM CDTTornado WarningOUNAlfalfa, Garfield, Major23 min
May 6, 4:54 PM CDTSevere Thunderstorm WarningOUNBaylor, Knox21 min
May 6, 4:56 PM CDTSevere Thunderstorm WarningSJTFisher, Haskell, Jones34 min
May 6, 5:02 PM CDTSevere Thunderstorm WarningOUNFoard, Knox13 min
May 6, 5:12 PM CDTSevere Thunderstorm WarningOUNBaylor, Foard, Hardeman, Knox, Wilbarger63 min
May 6, 5:15 PM CDTTornado WarningOUNAlfalfa, Garfield, Grant, Major30 min
May 6, 5:15 PM CDTSevere Thunderstorm WarningOUNBaylor, Knox, Wilbarger45 min
May 6, 5:21 PM CDTSevere Thunderstorm WarningOUNCaddo, Grady39 min
May 6, 5:22 PM CDTSevere Thunderstorm WarningFWDStephens37 min
May 6, 5:22 PM CDTSevere Thunderstorm WarningSJTThrockmorton38 min
May 6, 5:24 PM CDTSevere Thunderstorm WarningOUNBlaine, Dewey51 min
May 6, 5:25 PM CDTTornado Warning EmergencyTornado observedCatastrophic damage threatOUNCleveland, Grady, McClain9 min
May 6, 5:29 PM CDTTornado WarningOUNCleveland, McClain31 min
May 6, 5:29 PM CDTSevere Thunderstorm WarningSJTFisher, Haskell, Jones46 min
May 6, 5:34 PM CDTSevere Thunderstorm WarningSJTShackelford, Throckmorton56 min
May 6, 5:44 PM CDTTornado WarningOUNGarfield, Grant31 min
May 6, 5:48 PM CDTSevere Thunderstorm WarningOUNBaylor42 min
May 6, 5:55 PM CDTSevere Thunderstorm WarningOUNJackson, Tillman50 min
May 6, 5:56 PM CDTTornado WarningOUNCleveland34 min
May 6, 5:58 PM CDTSevere Thunderstorm WarningFWDYoung43 min
May 6, 6:04 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Grant41 min
May 6, 6:04 PM CDTSevere Thunderstorm WarningOUNCotton, Tillman16 min
May 6, 6:06 PM CDTFlash Flood Warning EmergencyOUNCaddo, Canadian, Cleveland, Grady, McClain, Oklahoma15 hr
May 6, 6:09 PM CDTSevere Thunderstorm WarningOUNCleveland, Oklahoma51 min
May 6, 6:12 PM CDTSevere Thunderstorm WarningOUNCaddo, Canadian, Grady48 min
May 6, 6:13 PM CDTSevere Thunderstorm WarningOUNGrant32 min
May 6, 6:13 PM CDTSevere Thunderstorm WarningSJTJones, Shackelford47 min
May 6, 6:17 PM CDTTornado WarningOUNCleveland, Oklahoma28 min
May 6, 6:18 PM CDTSevere Thunderstorm WarningOUNBlaine, Dewey, Major42 min
May 6, 6:21 PM CDTSevere Thunderstorm WarningOUNAlfalfa24 min
May 6, 6:24 PM CDTSevere Thunderstorm WarningOUNArcher, Baylor, Wichita, Wilbarger51 min
May 6, 6:31 PM CDTTornado WarningOUNCaddo, Canadian, Grady29 min
May 6, 6:36 PM CDTTornado Warning Tornado observedOUNBlaine, Dewey, Major24 min
May 6, 6:39 PM CDTTornado WarningOUNCleveland, Lincoln, Oklahoma, Pottawatomie20 min
May 6, 6:43 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Grant32 min
May 6, 6:48 PM CDTSevere Thunderstorm WarningOUNJackson, Kiowa, Tillman29 min
May 6, 6:49 PM CDTSevere Thunderstorm WarningSJTHaskell, Jones, Throckmorton41 min
May 6, 6:57 PM CDTTornado WarningOUNGrant33 min
May 6, 6:57 PM CDTTornado Warning Tornado observedOUNGrady33 min
May 6, 7:00 PM CDTSevere Thunderstorm WarningOUNCotton, Tillman45 min
May 6, 7:00 PM CDTTornado WarningOUNMajor30 min
May 6, 7:02 PM CDTSevere Thunderstorm WarningOUNCanadian, Cleveland, Grady, McClain, Oklahoma43 min
May 6, 7:09 PM CDTSevere Thunderstorm WarningOUNCanadian, Grady51 min
May 6, 7:24 PM CDTSevere Thunderstorm WarningOUNCaddo, Comanche, Kiowa51 min
May 6, 7:25 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Dewey, Major, Woods50 min
May 6, 7:25 PM CDTTornado WarningOUNGrady35 min
May 6, 7:27 PM CDTSevere Thunderstorm WarningOUNTillman48 min
May 6, 7:27 PM CDTTornado WarningOUNGrant33 min
May 6, 7:29 PM CDTSevere Thunderstorm WarningOUNCaddo, Grady31 min
May 6, 7:29 PM CDTSevere Thunderstorm WarningSJTHaskell, Throckmorton46 min
May 6, 7:32 PM CDTSevere Thunderstorm WarningOUNArcher, Baylor, Wichita, Wilbarger43 min
May 6, 7:35 PM CDTSevere Thunderstorm WarningOUNComanche, Cotton, Stephens, Tillman40 min
May 6, 7:45 PM CDTSevere Thunderstorm WarningOUNCanadian, Cleveland, Grady, McClain, Oklahoma45 min
May 6, 7:57 PM CDTTornado WarningOUNOklahoma33 min
May 6, 7:59 PM CDTTornado WarningOUNCanadian, Grady46 min
May 6, 8:02 PM CDTSevere Thunderstorm WarningOUNBaylor, Foard, Knox43 min
May 6, 8:04 PM CDTSevere Thunderstorm WarningOUNCanadian, Grady41 min
May 6, 8:07 PM CDTTornado WarningOUNArcher23 min
May 6, 8:10 PM CDTSevere Thunderstorm WarningSJTHaskell, Throckmorton50 min
May 6, 8:14 PM CDTSevere Thunderstorm WarningOUNCaddo, Canadian, Grady46 min
May 6, 8:16 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Major, Woods44 min
May 6, 8:17 PM CDTTornado WarningSJTHaskell, Throckmorton43 min
May 6, 8:25 PM CDTTornado WarningOUNCleveland, Oklahoma35 min
May 6, 8:28 PM CDTTornado WarningOUNGrady, McClain32 min
May 6, 8:29 PM CDTTornado WarningOUNArcher31 min
May 6, 8:34 PM CDTSevere Thunderstorm WarningOUNCanadian, Cleveland, Grady, McClain, Oklahoma41 min
May 6, 8:36 PM CDTSevere Thunderstorm WarningOUNComanche, Jackson, Kiowa, Tillman39 min
May 6, 8:53 PM CDTTornado WarningSJTHaskell, Throckmorton52 min
May 6, 8:54 PM CDTSevere Thunderstorm WarningOUNBaylor, Foard, Hardeman, Knox, Wilbarger51 min
May 6, 8:56 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Garfield, Grant, Woods49 min
May 6, 8:56 PM CDTSevere Thunderstorm WarningSJTHaskell, Throckmorton64 min
May 6, 8:57 PM CDTTornado WarningOUNArcher, Wichita48 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 6.4 hours before the alert went out and 186 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Norman, OK at 12:00Z on 2015-05-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1226 joules per kilogram.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.
HodographHodograph, Norman, OK at 12:00Z on 2015-05-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 219 square meters per square second.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.
Mixed-layer CAPE
1226 J/kg
Mixed-layer CIN
-16 J/kg
Mixed-layer LCL
562 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
219 m²/s²
0-3 km storm-relative helicity
308 m²/s²
Significant tornado parameter
1.2
Supercell composite
9.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

666 
WWUS20 KWNS 061821
SEL3  
SPC WW 061821
OKZ000-TXZ000-070200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 133
NWS STORM PREDICTION CENTER NORMAN OK
125 PM CDT WED MAY 6 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  WESTERN OKLAHOMA
  WESTERN NORTH TEXAS

* EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 125 PM
  UNTIL 900 PM CDT.

* PRIMARY THREATS INCLUDE...
  A FEW TORNADOES AND A COUPLE INTENSE TORNADOES POSSIBLE
  WIDESPREAD LARGE HAIL LIKELY WITH ISOLATED VERY LARGE HAIL
    EVENTS TO 3 INCHES IN DIAMETER POSSIBLE
  SCATTERED DAMAGING WIND GUSTS TO 70 MPH LIKELY

SUMMARY...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER
SOUTHWEST OK AND WESTERN NORTH TX THIS AFTERNOON...WITH MORE
ISOLATED ACTIVITY POSSIBLE IN THE NORTHERN PORTIONS OF THE WATCH. 
ANY STORM THAT FORMS WILL POSE A RISK OF VERY LARGE HAIL...DAMAGING
WINDS...AND PERHAPS TORNADOES.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 55 MILES WEST SOUTHWEST OF
MINERAL WELLS TEXAS TO 5 MILES NORTH OF ALVA OKLAHOMA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU3).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

&&

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24025.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 6, 1:03 PM CDTMesoscale DiscussionSPCComanche, Cotton, Greer, Harmon, Jackson, Jefferson and 3 more117 min
May 6, 1:09 PM CDTMesoscale DiscussionSPCWoods3 hr
May 6, 3:27 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Carter and 28 more2 hr
May 6, 5:25 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Carter, Cleveland and 27 more2 hr
May 6, 6:34 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Carter and 34 more86 min
May 5, 7:41 PM CDTMesoscale DiscussionSPCBorden, Briscoe, Childress, Cottle, Crosby, Dickens and 15 more2 hr
May 5, 8:07 PM CDTTornado WatchSPCCoke, Cottle, Crosby, Dickens, Fisher, Foard and 14 more4 hr
May 5, 9:56 PM CDTMesoscale DiscussionSPCBorden, Callahan, Coke, Cottle, Crosby, Dickens and 23 more94 min
May 6, 1:46 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 22 more119 min
May 6, 3:00 PM CDTTornado WatchSPCBrown, Coke, Coleman, Concho, Crockett, Fisher and 12 more7 hr

Nearby

Tornado Watches in Oklahoma, 2015Tornado Watches in Texas, 2015Every tornado watch in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.