Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 69, NWS Norman, OK

April 9, 2021Grady County, McClain County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 9, 2021, 5:31 PM CDT for Grady County, McClain County, Oklahoma. It was in force for 44 min. 7 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 9, 2021, 5:31 PM CDT (22:31 UTC)
Expired: Apr 9, 2021, 6:15 PM CDT
In force: 44 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 2.0 in
Wind: 60.0 mph

Counties Grady County, OK, McClain County, OK

The radar

The Norman radar (KTLX), 61 km from the middle of the area, began a volume at 22:31 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 was reported inside it

Time	Report	Where	Remark
Apr 9, 5:34 PM CDT	HAIL 1.75	1 S Chickasha, OK
Apr 9, 5:35 PM CDT	HAIL 1.25	2 E Chickasha, OK
Apr 9, 5:43 PM CDT	HAIL 2.5	3 E Chickasha, OK	ON HWY 19
Apr 9, 5:45 PM CDT	HAIL 2.75	6 Se Chickasha, OK
Apr 9, 5:52 PM CDT	HAIL 1.25	5 Ese Ninnekah, OK
Apr 9, 5:55 PM CDT	HAIL 1.75	4 Ene Ninnekah, OK
Apr 9, 5:55 PM CDT	HAIL 2	2 Nw Alex, OK

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

Issued	Product	Office	Lasted
Apr 9, 3:55 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Norman, OK (KOUN), launched 12:00Z, 10.5 hours before the alert went out and 45 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

340 
WUUS54 KOUN 092231
SVROUN
OKC051-087-092315-
/O.NEW.KOUN.SV.W.0069.210409T2231Z-210409T2315Z/

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

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Southeastern Grady County in central Oklahoma...
  Southwestern McClain County in central Oklahoma...

* Until 615 PM CDT.

* At 530 PM CDT, a severe thunderstorm was located 4 miles northeast
  of Chickasha, moving southeast at 25 mph.

  HAZARD...Two inch 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...
  Chickasha, Dibble, Alex, Amber, Bradley, Middleberg, Tabler, Criner
  and Ninnekah.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows!

&&

LAT...LON 3480 9778 3508 9800 3519 9784 3494 9748
TIME...MOT...LOC 2230Z 312DEG 20KT 3508 9790 

HAIL...2.00IN
WIND...60MPH
 
$$

Mahale

3 follow-up statements

126 
WWUS54 KOUN 092246
SVSOUN

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

OKC051-087-092315-
/O.CON.KOUN.SV.W.0069.000000T0000Z-210409T2315Z/
Grady OK-McClain OK-
546 PM CDT Fri Apr 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CDT
FOR SOUTHEASTERN GRADY AND SOUTHWESTERN MCCLAIN COUNTIES...

At 545 PM CDT, a severe thunderstorm was located near Tabler, moving
southeast at 25 mph.

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

SOURCE...Trained weather spotters reported tennis ball size hail 
         east of Chickasha.

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...
Dibble, Alex, Bradley, Middleberg, Tabler and Criner. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a dangerous storm. Prepare immediately for large destructive
hail capable of producing significant damage. People outside should
move to a shelter, inside a strong building and away from windows.

&&

LAT...LON 3509 9784 3514 9777 3494 9748 3480 9778
      3499 9792
TIME...MOT...LOC 2245Z 312DEG 20KT 3502 9782 

HAIL...2.50IN
WIND...60MPH
 
$$

Mahale

760 
WWUS54 KOUN 092256
SVSOUN

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

OKC051-087-092315-
/O.CON.KOUN.SV.W.0069.000000T0000Z-210409T2315Z/
Grady OK-McClain OK-
556 PM CDT Fri Apr 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CDT
FOR SOUTHEASTERN GRADY AND SOUTHWESTERN MCCLAIN COUNTIES...

At 555 PM CDT, a severe thunderstorm was located near Alex, moving
southeast at 25 mph.

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

SOURCE...There have been several reports of large hail by trained 
         weather spotters east of Ninnekah. 

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...
Dibble, Alex, Bradley and Criner. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a dangerous storm. Prepare immediately for large destructive
hail capable of producing significant damage. People outside should
move to a shelter, inside a strong building and away from windows.

&&

LAT...LON 3502 9783 3508 9768 3494 9748 3480 9778
      3496 9790
TIME...MOT...LOC 2255Z 316DEG 22KT 3497 9777 

HAIL...2.50IN
WIND...60MPH
 
$$

Mahale

519 
WWUS54 KOUN 092302
SVSOUN

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

OKC051-087-092315-
/O.CON.KOUN.SV.W.0069.000000T0000Z-210409T2315Z/
Grady OK-McClain OK-
602 PM CDT Fri Apr 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CDT
FOR SOUTHEASTERN GRADY AND SOUTHWESTERN MCCLAIN COUNTIES...

At 602 PM CDT, a severe thunderstorm was located near Alex, moving
south at 30 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...
Alex and Bradley. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 3497 9782 3502 9771 3491 9755 3480 9778
      3493 9788
TIME...MOT...LOC 2302Z 343DEG 28KT 3491 9775 

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

Mahale

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 9, 2:57 AM CDT	Wind Advisory	OUN	Alfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 31 more	20 hr
Apr 9, 10:21 AM CDT	Special Weather Statement	OUN	Bryan	24 min
Apr 9, 10:32 AM CDT	Special Weather Statement	OUN	Bryan	28 min
Apr 9, 3:21 PM CDT	Special Weather Statement	OUN	Greer	24 min
Apr 9, 3:28 PM CDT	Severe Thunderstorm Warning	OUN	Greer	23 min
Apr 9, 3:35 PM CDT	Special Weather Statement	OUN	Washita	40 min
Apr 9, 3:39 PM CDT	Special Weather Statement	OUN	Kingfisher	36 min
Apr 9, 3:49 PM CDT	Special Weather Statement	OUN	Canadian	26 min
Apr 9, 3:52 PM CDT	Special Weather Statement	OUN	Greer	23 min
Apr 9, 3:57 PM CDT	Severe Thunderstorm Warning	OUN	Caddo, Canadian, Grady	48 min
Apr 9, 4:12 PM CDT	Special Weather Statement	OUN	Logan	33 min
Apr 9, 4:13 PM CDT	Special Weather Statement	OUN	Washita	32 min
Apr 9, 4:23 PM CDT	Special Weather Statement	OUN	Grant	37 min
Apr 9, 4:25 PM CDT	Severe Thunderstorm Warning	OUN	Logan, Payne	50 min
Apr 9, 4:29 PM CDT	Severe Thunderstorm Warning	OUN	Kiowa, Washita	16 min
Apr 9, 4:36 PM CDT	Severe Thunderstorm Warning	OUN	Caddo, Canadian, Grady	39 min
Apr 9, 4:52 PM CDT	Special Weather Statement	OUN	Kingfisher	23 min
Apr 9, 4:53 PM CDT	Severe Thunderstorm Warning	OUN	Kingfisher	52 min
Apr 9, 5:06 PM CDT	Severe Thunderstorm Warning	OUN	Grady	39 min
Apr 9, 5:17 PM CDT	Severe Thunderstorm Warning	OUN	Logan, Noble, Payne	43 min
Apr 9, 5:18 PM CDT	Severe Thunderstorm Warning	OUN	Kingfisher, Logan, Oklahoma	42 min
Apr 9, 5:25 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Payne	50 min
Apr 9, 5:36 PM CDT	Special Weather Statement	OUN	Pottawatomie	24 min
Apr 9, 5:39 PM CDT	Special Weather Statement	OUN	Lincoln	36 min
Apr 9, 5:48 PM CDT	Special Weather Statement	OUN	Lincoln	27 min
Apr 9, 5:51 PM CDT	Severe Thunderstorm Warning	OUN	Pottawatomie, Seminole	39 min
Apr 9, 5:57 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Logan, Oklahoma	48 min
Apr 9, 6:05 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Grady, McClain, Stephens	40 min
Apr 9, 6:09 PM CDT	Special Weather Statement	OUN	Lincoln	36 min
Apr 9, 6:22 PM CDT	Severe Thunderstorm Warning	OUN	Pottawatomie, Seminole	27 min
Apr 9, 6:34 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln	56 min
Apr 9, 6:38 PM CDT	Special Weather Statement	OUN	Pottawatomie	52 min
Apr 9, 6:58 PM CDT	Special Weather Statement	OUN	Pottawatomie, Seminole	47 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2021 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.