Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 7, NWS Norman, OK

February 28, 2021Atoka County, Bryan County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Feb 28, 2021, 10:29 AM CST for Atoka County, Bryan County, Oklahoma. It was in force for 26 min. 1 report 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: Feb 28, 2021, 10:29 AM CST (16:29 UTC)
Expired: Feb 28, 2021, 10:55 AM CST
In force: 26 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.5 in
Wind: 60.0 mph

Counties Atoka County, OK, Bryan County, OK

The radar

The Norman radar (KTLX), 200 km from the middle of the area, began a volume at 16:31 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
Feb 28, 10:33 AM CST	HAIL 0.7	Bennington, OK	DIME SIZE HAIL COVERING THE GROUND NEAR BENNINGTON.

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

The nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 4.5 hours before the alert went out and 181 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: 1316 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 666 m above ground
0-6 km bulk shear: 71 kt
0-1 km storm-relative helicity: 165 m²/s²
0-3 km storm-relative helicity: 109 m²/s²
Significant tornado parameter: 1.2
Supercell composite: 3.6

Open this sounding in Storm Lab

The text

As transmitted.

204 
WUUS54 KOUN 281629
SVROUN
OKC005-013-281715-
/O.NEW.KOUN.SV.W.0007.210228T1629Z-210228T1715Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
1029 AM CST Sun Feb 28 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Northeastern Bryan County in southeastern Oklahoma...
  Southeastern Atoka County in southeastern Oklahoma...

* Until 1115 AM CST.

* At 1029 AM CST, a severe thunderstorm was located near Bennington,
  moving northeast at 55 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...
  Bennington and Darwin. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

Large hail, damaging winds, and continuous cloud to ground lightning 
is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 3385 9578 3386 9581 3384 9582 3384 9585
      3389 9593 3387 9594 3386 9597 3411 9619
      3428 9578 3416 9578 3415 9596 3412 9594
      3394 9594 3392 9592 3392 9588 3387 9584
      3387 9576 3386 9575
TIME...MOT...LOC 1629Z 239DEG 57KT 3395 9606 

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

03

1 follow-up statement

789 
WWUS54 KOUN 281655
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
1055 AM CST Sun Feb 28 2021

OKC005-013-281705-
/O.CAN.KOUN.SV.W.0007.000000T0000Z-210228T1715Z/
Bryan OK-Atoka OK-
1055 AM CST Sun Feb 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BRYAN AND
SOUTHEASTERN ATOKA COUNTIES IS CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.

LAT...LON 3385 9578 3386 9581 3384 9582 3384 9585
      3389 9593 3387 9594 3386 9597 3411 9619
      3428 9578 3416 9578 3415 9596 3412 9594
      3394 9594 3392 9592 3392 9588 3387 9584
      3387 9576 3386 9575
TIME...MOT...LOC 1654Z 239DEG 57KT 3417 9563 

$$

03

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 27, 9:08 PM CST	Dense Fog Advisory	OUN	Atoka, Blaine, Bryan, Caddo, Canadian, Carter and 22 more	8 hr
Feb 28, 9:49 AM CST	Special Weather Statement	OUN	Bryan	41 min
Feb 28, 10:02 AM CST	Severe Thunderstorm Warning	OUN	Bryan, Marshall	43 min
Feb 28, 10:53 AM CST	Special Weather Statement	OUN	Bryan	52 min
Feb 28, 11:25 AM CST	Special Weather Statement	OUN	Bryan	20 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.