Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 72, NWS Norman, OK

April 9, 20214 counties in Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 9, 2021, 6:05 PM CDT for 4 counties in Oklahoma. It was in force for 40 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 9, 2021, 6:05 PM CDT (23:05 UTC)
Expired
Apr 9, 2021, 6:45 PM CDT
In force
40 min
Issued by
NWS Norman, OK
Area
Storm-based polygon
Hail
1.75 in
Wind
60.0 mph

Counties Garvin County, OK, Grady County, OK, McClain County, OK, Stephens County, OK

The radar

The Norman radar (KTLX), 72 km from the middle of the area, began a volume at 23:07 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 9, 3:55 PM CDTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 11.1 hours before the alert went out and 55 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 2021-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1068 joules per kilogram.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.
HodographHodograph, Norman, OK at 12:00Z on 2021-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.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.
Mixed-layer CAPE
1068 J/kg
Mixed-layer CIN
-311 J/kg
Mixed-layer LCL
1414 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
137 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.6

Open this sounding in Storm Lab

The text

As transmitted.

085 
WUUS54 KOUN 092305
SVROUN
OKC049-051-087-137-092345-
/O.NEW.KOUN.SV.W.0072.210409T2305Z-210409T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
605 PM CDT Fri Apr 9 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Northwestern Garvin County in southern Oklahoma...
  Southeastern Grady County in central Oklahoma...
  Northeastern Stephens County in southern Oklahoma...
  Southwestern McClain County in central Oklahoma...

* Until 645 PM CDT.

* At 604 PM CDT, severe thunderstorms were located along a line
  extending from 4 miles east of Agawam to 4 miles north of Bradley,
  moving southeast at 20 mph.

  HAZARD...Golf ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* Locations impacted include...
  Lindsay, Maysville, Alex, Bradley, Antioch, Cox City, Whitebead,
  Erin Springs and Payne.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

These storms are producing large hail. SEEK SHELTER NOW inside a
sturdy structure and stay away from windows!

&&

LAT...LON 3462 9774 3477 9723 3499 9767 3486 9793
TIME...MOT...LOC 2304Z 311DEG 17KT 3485 9787 3494 9769 

HAIL...1.75IN
WIND...60MPH
 
$$

Mahale
3 follow-up statements
333 
WWUS54 KOUN 092313
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
613 PM CDT Fri Apr 9 2021

OKC049-051-087-137-092345-
/O.CON.KOUN.SV.W.0072.000000T0000Z-210409T2345Z/
Garvin OK-Grady OK-Stephens OK-McClain OK-
613 PM CDT Fri Apr 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CDT
FOR NORTHWESTERN GARVIN...SOUTHEASTERN GRADY...NORTHEASTERN STEPHENS
AND SOUTHWESTERN MCCLAIN COUNTIES...

At 613 PM CDT, severe thunderstorms were located along a line
extending from 6 miles southeast of Agawam to 3 miles northeast of
Bradley, moving southeast at 20 mph.

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Lindsay, Maysville, Alex, Bradley, Antioch, Cox City, Whitebead and
Erin Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3482 9790 3495 9769 3477 9723 3462 9774
TIME...MOT...LOC 2313Z 311DEG 17KT 3483 9784 3492 9766 

HAIL...1.50IN
WIND...60MPH
 
$$

Mahale
027 
WWUS54 KOUN 092324
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
624 PM CDT Fri Apr 9 2021

OKC087-092334-
/O.CAN.KOUN.SV.W.0072.000000T0000Z-210409T2345Z/
McClain OK-
624 PM CDT Fri Apr 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MCCLAIN COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

LAT...LON 3478 9786 3487 9771 3471 9743 3462 9774
TIME...MOT...LOC 2324Z 322DEG 18KT 3476 9781 3484 9766 

$$

OKC049-051-137-092345-
/O.CON.KOUN.SV.W.0072.000000T0000Z-210409T2345Z/
Garvin OK-Grady OK-Stephens OK-
624 PM CDT Fri Apr 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM CDT
FOR WEST CENTRAL GARVIN...SOUTHEASTERN GRADY AND NORTHEASTERN
STEPHENS COUNTIES...

At 624 PM CDT, severe thunderstorms were located along a line
extending from 8 miles north of Bray to 3 miles west of Lindsay,
moving southeast at 20 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Cox City and Erin Springs. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3478 9786 3487 9771 3471 9743 3462 9774
TIME...MOT...LOC 2324Z 322DEG 18KT 3476 9781 3484 9766 

HAIL...1.00IN
WIND...60MPH
 
$$

Mahale
797 
WWUS54 KOUN 092337
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
637 PM CDT Fri Apr 9 2021

OKC049-051-137-092347-
/O.EXP.KOUN.SV.W.0072.000000T0000Z-210409T2345Z/
Garvin OK-Grady OK-Stephens OK-
637 PM CDT Fri Apr 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL GARVIN...
SOUTHEASTERN GRADY AND NORTHEASTERN STEPHENS COUNTIES WILL EXPIRE AT
645 PM CDT...
             
The storms which prompted the warning have weakened below severe
limits, therefore the warning will be allowed to expire.  However
small hail and heavy rain are still possible with these
thunderstorms.

LAT...LON 3478 9786 3487 9771 3471 9743 3462 9774
TIME...MOT...LOC 2337Z 311DEG 17KT 3472 9776 3480 9761 

$$

Mahale

The office that day

Everything else NWS Norman, OK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 9, 2:57 AM CDTWind AdvisoryOUNAlfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 31 more20 hr
Apr 9, 10:21 AM CDTSpecial Weather StatementOUNBryan24 min
Apr 9, 10:32 AM CDTSpecial Weather StatementOUNBryan28 min
Apr 9, 3:21 PM CDTSpecial Weather StatementOUNGreer24 min
Apr 9, 3:28 PM CDTSevere Thunderstorm WarningOUNGreer23 min
Apr 9, 3:35 PM CDTSpecial Weather StatementOUNWashita40 min
Apr 9, 3:39 PM CDTSpecial Weather StatementOUNKingfisher36 min
Apr 9, 3:49 PM CDTSpecial Weather StatementOUNCanadian26 min
Apr 9, 3:52 PM CDTSpecial Weather StatementOUNGreer23 min
Apr 9, 3:57 PM CDTSevere Thunderstorm WarningOUNCaddo, Canadian, Grady48 min
Apr 9, 4:12 PM CDTSpecial Weather StatementOUNLogan33 min
Apr 9, 4:13 PM CDTSpecial Weather StatementOUNWashita32 min
Apr 9, 4:23 PM CDTSpecial Weather StatementOUNGrant37 min
Apr 9, 4:25 PM CDTSevere Thunderstorm WarningOUNLogan, Payne50 min
Apr 9, 4:29 PM CDTSevere Thunderstorm WarningOUNKiowa, Washita16 min
Apr 9, 4:36 PM CDTSevere Thunderstorm WarningOUNCaddo, Canadian, Grady39 min
Apr 9, 4:52 PM CDTSpecial Weather StatementOUNKingfisher23 min
Apr 9, 4:53 PM CDTSevere Thunderstorm WarningOUNKingfisher52 min
Apr 9, 5:06 PM CDTSevere Thunderstorm WarningOUNGrady39 min
Apr 9, 5:17 PM CDTSevere Thunderstorm WarningOUNLogan, Noble, Payne43 min
Apr 9, 5:18 PM CDTSevere Thunderstorm WarningOUNKingfisher, Logan, Oklahoma42 min
Apr 9, 5:25 PM CDTSevere Thunderstorm WarningOUNLincoln, Logan, Payne50 min
Apr 9, 5:31 PM CDTSevere Thunderstorm WarningOUNGrady, McClain44 min
Apr 9, 5:36 PM CDTSpecial Weather StatementOUNPottawatomie24 min
Apr 9, 5:39 PM CDTSpecial Weather StatementOUNLincoln36 min
Apr 9, 5:48 PM CDTSpecial Weather StatementOUNLincoln27 min
Apr 9, 5:51 PM CDTSevere Thunderstorm WarningOUNPottawatomie, Seminole39 min
Apr 9, 5:57 PM CDTSevere Thunderstorm WarningOUNLincoln, Logan, Oklahoma48 min
Apr 9, 6:09 PM CDTSpecial Weather StatementOUNLincoln36 min
Apr 9, 6:22 PM CDTSevere Thunderstorm WarningOUNPottawatomie, Seminole27 min
Apr 9, 6:34 PM CDTSevere Thunderstorm WarningOUNLincoln56 min
Apr 9, 6:38 PM CDTSpecial Weather StatementOUNPottawatomie52 min
Apr 9, 6:58 PM CDTSpecial Weather StatementOUNPottawatomie, Seminole47 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2021Every severe thunderstorm warning in 2021

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.