Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 79, NWS Norman, OK

April 9, 20216 counties in Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Apr 9, 2021, 7:51 PM CDT for 6 counties in Oklahoma. It was in force for 54 min. 5 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, 7:51 PM CDT (00:51 UTC)
Expired: Apr 9, 2021, 8:45 PM CDT
In force: 54 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.75 in
Wind: 70.0 mph

Counties Coal County, OK, Hughes County, OK, Johnston County, OK, Murray County, OK, Pontotoc County, OK, Seminole County, OK

The radar

The Norman radar (KTLX), 89 km from the middle of the area, began a volume at 00:51 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
Apr 9, 7:53 PM CDT	HAIL 1	6 W Roff, OK
Apr 9, 7:57 PM CDT	HAIL 1	4 W Ada, OK
Apr 9, 8:00 PM CDT	HAIL 1.75	Fitzhugh, OK
Apr 9, 8:02 PM CDT	HAIL 1.1	3 E Sulphur, OK
Apr 9, 8:39 PM CDT	HAIL 1	Bromide, 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 00:00Z, 0.9 hours before the alert went out and 90 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: 1392 J/kg
Mixed-layer CIN: -25 J/kg
Mixed-layer LCL: 1212 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 38 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

010 
WUUS54 KOUN 100051
SVROUN
OKC029-063-069-099-123-133-100145-
/O.NEW.KOUN.SV.W.0079.210410T0051Z-210410T0145Z/

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

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Northeastern Johnston County in southeastern Oklahoma...
  Coal County in southeastern Oklahoma...
  Southern Seminole County in east central Oklahoma...
  Pontotoc County in east central Oklahoma...
  Northeastern Murray County in southern Oklahoma...
  Southern Hughes County in southeastern Oklahoma...

* Until 845 PM CDT.

* At 751 PM CDT, severe thunderstorms were located along a line
  extending from near Wewoka to near Ada to 3 miles west of Hickory,
  moving east at 30 mph.

  HAZARD...Golf ball size hail and 70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           considerable tree damage. Wind damage is also likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Ada, Holdenville, Sulphur, Byng, Allen, Roff, Stonewall, Tupelo,
  Francis, Calvin, Fitzhugh, Stuart, Bromide, Sasakwa, Gerty,
  Centrahoma, Horntown, Atwood, Hickory and Clarita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3505 9609 3469 9609 3438 9649 3452 9709
      3464 9698 3464 9693 3472 9693 3475 9689
      3509 9664 3507 9606
TIME...MOT...LOC 0051Z 275DEG 26KT 3513 9648 3478 9669 3455 9693 

HAIL...1.75IN
WIND...70MPH
 
$$

Mahale

3 follow-up statements

332 
WWUS54 KOUN 100108
SVSOUN

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

OKC029-063-069-099-123-133-100145-
/O.CON.KOUN.SV.W.0079.000000T0000Z-210410T0145Z/
Johnston OK-Coal OK-Seminole OK-Pontotoc OK-Murray OK-Hughes OK-
808 PM CDT Fri Apr 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR NORTHEASTERN JOHNSTON...COAL...SOUTHEASTERN SEMINOLE...
PONTOTOC...EAST CENTRAL MURRAY AND SOUTHERN HUGHES COUNTIES...

At 808 PM CDT, severe thunderstorms were located along a line
extending from 3 miles east of Holdenville to 6 miles east of Ada to
3 miles southeast of Scullin, moving east at 30 mph.

HAZARD...70 mph wind gusts and ping pong ball size hail.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect 
         considerable tree damage. Wind damage is also likely to 
         mobile homes, roofs, and outbuildings.

Locations impacted include...
Ada, Holdenville, Sulphur, Allen, Stonewall, Tupelo, Francis, Calvin,
Fitzhugh, Stuart, Bromide, Sasakwa, Gerty, Centrahoma, Horntown,
Atwood, Hickory, Pontotoc, Fittstown and Clarita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3505 9609 3469 9609 3438 9649 3449 9698
      3458 9686 3475 9670 3508 9646 3507 9606
TIME...MOT...LOC 0108Z 274DEG 26KT 3508 9634 3477 9654 3449 9681 

HAIL...1.50IN
WIND...70MPH
 
$$

Mahale

288 
WWUS54 KOUN 100119
SVSOUN

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

OKC099-133-100129-
/O.CAN.KOUN.SV.W.0079.000000T0000Z-210410T0145Z/
Seminole OK-Murray OK-
819 PM CDT Fri Apr 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SEMINOLE AND EAST
CENTRAL MURRAY COUNTIES IS CANCELLED...

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

LAT...LON 3505 9609 3469 9609 3438 9649 3447 9688
      3448 9688 3451 9684 3451 9683 3452 9683
      3475 9654 3508 9635 3507 9606
TIME...MOT...LOC 0119Z 272DEG 28KT 3505 9620 3474 9640 3446 9667 

$$

OKC029-063-069-123-100145-
/O.CON.KOUN.SV.W.0079.000000T0000Z-210410T0145Z/
Johnston OK-Coal OK-Pontotoc OK-Hughes OK-
819 PM CDT Fri Apr 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR NORTHEASTERN JOHNSTON...COAL...SOUTHEASTERN PONTOTOC AND SOUTHERN
HUGHES COUNTIES...

At 819 PM CDT, severe thunderstorms were located along a line
extending from 3 miles southeast of Horntown to 9 miles northeast of
Stonewall to near Connerville, moving east at 35 mph.

HAZARD...70 mph wind gusts and ping pong ball size hail.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect 
         considerable tree damage. Wind damage is also likely to 
         mobile homes, roofs, and outbuildings.

Locations impacted include...
Allen, Stonewall, Tupelo, Calvin, Stuart, Bromide, Gerty, Centrahoma,
Horntown, Atwood, Pontotoc, Fittstown, Clarita, Connerville and
Jesse.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms.

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

&&

LAT...LON 3505 9609 3469 9609 3438 9649 3447 9688
      3448 9688 3451 9684 3451 9683 3452 9683
      3475 9654 3508 9635 3507 9606
TIME...MOT...LOC 0119Z 272DEG 28KT 3505 9620 3474 9640 3446 9667 

TORNADO...POSSIBLE
HAIL...1.50IN
WIND...70MPH
 
$$

Mahale

277 
WWUS54 KOUN 100123
SVSOUN

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

OKC029-063-069-123-100145-
/O.CON.KOUN.SV.W.0079.000000T0000Z-210410T0145Z/
Johnston OK-Coal OK-Pontotoc OK-Hughes OK-
823 PM CDT Fri Apr 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR NORTHEASTERN JOHNSTON...COAL...SOUTHEASTERN PONTOTOC AND SOUTHERN
HUGHES COUNTIES...

At 822 PM CDT, severe thunderstorms were located along a line
extending from 4 miles southwest of Lamar to 8 miles southwest of 
Gerty to near Connerville, moving east at 30 mph. The most dangerous 
part of the storm is near Calvin and will move toward Stuart. 

These are very dangerous storms.

HAZARD...80 mph wind gusts and ping pong ball size hail.

SOURCE...Radar indicated.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be heavily damaged. Expect 
         considerable damage to roofs, windows, and vehicles. 
         Extensive tree damage and power outages are likely.

Locations impacted include...
Allen, Stonewall, Tupelo, Calvin, Stuart, Bromide, Gerty, Centrahoma,
Horntown, Atwood, Pontotoc, Fittstown, Clarita, Connerville and
Jesse.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms.

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

&&

LAT...LON 3505 9609 3469 9609 3438 9649 3446 9685
      3450 9680 3479 9649 3508 9633 3507 9606
TIME...MOT...LOC 0122Z 275DEG 26KT 3505 9618 3474 9638 3446 9665 

TORNADO...POSSIBLE
HAIL...1.50IN
WIND...80MPH
 
$$

Mahale

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 9, 7:08 PM CDT	Severe Thunderstorm Warning	OUN	McClain, Pontotoc, Pottawatomie, Seminole	52 min
Apr 9, 7:27 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, McClain, Pontotoc, Pottawatomie, Seminole	33 min
Apr 9, 7:35 PM CDT	Special Weather Statement	OUN	Marshall	25 min
Apr 9, 7:36 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Love, Marshall	39 min
Apr 9, 7:39 PM CDT	Severe Thunderstorm Warning	OUN	Hughes, Seminole	51 min
Apr 9, 8:07 PM CDT	Severe Thunderstorm Warning	OUN	Love, Marshall	53 min
Apr 9, 8:11 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Coal, Johnston, Marshall, Murray, Pontotoc	34 min
Apr 9, 8:38 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Bryan, Coal, Hughes, Johnston, Marshall	67 min
Apr 9, 9:15 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Bryan, Marshall	60 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.