Alert archive / Texas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 110, NWS Norman, OK

April 23, 2021Clay County, Wichita County, Texas; Cotton County, Jefferson County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 23, 2021, 8:18 PM CDT for Clay County, Wichita County, Texas; Cotton County, Jefferson County, Oklahoma. It was in force for 42 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 23, 2021, 8:18 PM CDT (01:18 UTC)
Expired: Apr 23, 2021, 9:00 PM CDT
In force: 42 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Cotton County, OK, Jefferson County, OK, Clay County, TX, Wichita County, TX

The radar

The Altus AFB radar (KFDR), 71 km from the middle of the area, began a volume at 01:22 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.

Issued	Product	Office	Lasted
Apr 23, 8:02 PM CDT	Severe Thunderstorm Watch	SPC	4 hr

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 1.3 hours before the alert went out and 152 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: 486 J/kg
Mixed-layer CIN: -47 J/kg
Mixed-layer LCL: 504 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 345 m²/s²
0-3 km storm-relative helicity: 408 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 6.8

Open this sounding in Storm Lab

The text

As transmitted.

708 
WUUS54 KOUN 240118
SVROUN
OKC033-067-TXC077-485-240200-
/O.NEW.KOUN.SV.W.0110.210424T0118Z-210424T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
818 PM CDT Fri Apr 23 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  West central Jefferson County in southern Oklahoma...
  Southeastern Cotton County in southwestern Oklahoma...
  Northwestern Clay County in northern Texas...
  East central Wichita County in northern Texas...

* Until 900 PM CDT.

* At 818 PM CDT, a severe thunderstorm was located 7 miles northwest
  of Petrolia, moving east at 30 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...
  Waurika, Petrolia, Byers, Taylor and Charlie. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3402 9848 3419 9837 3416 9800 3393 9811
TIME...MOT...LOC 0118Z 288DEG 28KT 3409 9833 

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

Ware

1 follow-up statement

731 
WWUS54 KOUN 240130
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
830 PM CDT Fri Apr 23 2021

TXC485-240140-
/O.CAN.KOUN.SV.W.0110.000000T0000Z-210424T0200Z/
Wichita TX-
830 PM CDT Fri Apr 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL WICHITA COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3399 9837 3418 9829 3416 9800 3393 9811
TIME...MOT...LOC 0130Z 288DEG 28KT 3406 9822 

$$

OKC033-067-TXC077-240200-
/O.CON.KOUN.SV.W.0110.000000T0000Z-210424T0200Z/
Jefferson OK-Cotton OK-Clay TX-
830 PM CDT Fri Apr 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM CDT
FOR WEST CENTRAL JEFFERSON...SOUTHEASTERN COTTON AND NORTHWESTERN
CLAY COUNTIES...

At 830 PM CDT, a severe thunderstorm was located near Byers, moving
east at 30 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...
Waurika, Petrolia, Byers and Charlie. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3399 9837 3418 9829 3416 9800 3393 9811
TIME...MOT...LOC 0130Z 288DEG 28KT 3406 9822 

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

Ware

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 23, 7:01 PM CDT	Severe Thunderstorm Warning	OUN	Wichita, Wilbarger	44 min
Apr 23, 7:06 PM CDT	Severe Thunderstorm Warning	OUN	Hardeman	39 min
Apr 23, 7:32 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Baylor, Wichita, Wilbarger	43 min
Apr 23, 7:44 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Wichita	46 min
Apr 23, 7:52 PM CDT	Severe Thunderstorm Warning	OUN	Clay, Wichita	37 min
Apr 23, 8:14 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Wichita	46 min
Apr 23, 8:33 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Clay, Wichita	42 min
Apr 23, 8:44 PM CDT	Severe Thunderstorm Warning	OUN	Clay	31 min
Apr 23, 8:46 PM CDT	Areal Flood Advisory	OUN	Wichita	3 hr
Apr 23, 9:02 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Clay	43 min
Apr 23, 9:12 PM CDT	Severe Thunderstorm Warning	OUN	Clay	48 min
Apr 23, 9:27 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Clay	48 min
Apr 23, 9:44 PM CDT	Severe Thunderstorm Warning	OUN	Clay	46 min
Apr 23, 7:15 PM CDT	Special Weather Statement	OUN	Garfield	30 min
Apr 23, 7:24 PM CDT	Special Weather Statement	OUN	Comanche	36 min
Apr 23, 8:00 PM CDT	Special Weather Statement	OUN	Grady	30 min
Apr 23, 8:04 PM CDT	Special Weather Statement	OUN	Stephens	26 min
Apr 23, 8:24 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Grady, McClain, Stephens	51 min
Apr 23, 8:36 PM CDT	Severe Thunderstorm Warning	OUN	Jefferson, Stephens	39 min
Apr 23, 8:53 PM CDT	Special Weather Statement	OUN	Cleveland, McClain	37 min
Apr 23, 8:59 PM CDT	Special Weather Statement	OUN	Garvin	31 min
Apr 23, 9:29 PM CDT	Special Weather Statement	OUN	Cleveland, Garvin, Pottawatomie	31 min
Apr 23, 10:00 PM CDT	Special Weather Statement	OUN	Carter, Murray, Pontotoc, Pottawatomie, Seminole	30 min
Apr 23, 10:29 PM CDT	Special Weather Statement	OUN	Coal, Hughes, Johnston, Love, Marshall, Pontotoc and 1 more	31 min
Apr 23, 11:00 PM CDT	Special Weather Statement	OUN	Atoka, Bryan, Coal, Hughes, Marshall, Seminole	30 min
Apr 23, 11:08 PM CDT	Areal Flood Advisory	OUN	Atoka, Bryan	3 hr

Nearby

Severe Thunderstorm Warnings in Texas, 2021 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.