Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 539, NWS Norman, OK

October 15, 20214 counties in Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Oct 15, 2021, 1:39 AM CDT for 4 counties in Oklahoma. It was in force for 51 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: Oct 15, 2021, 1:39 AM CDT (06:39 UTC)
Expired: Oct 15, 2021, 2:30 AM CDT
In force: 51 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Cleveland County, OK, Lincoln County, OK, Pottawatomie County, OK, Seminole County, OK

The radar

The Norman radar (KTLX), 59 km from the middle of the area, began a volume at 06:39 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 nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 6.7 hours before the alert went out and 72 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: 421 J/kg
Mixed-layer CIN: -54 J/kg
Mixed-layer LCL: 1034 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 99 m²/s²
0-3 km storm-relative helicity: 161 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.5

Open this sounding in Storm Lab

The text

As transmitted.

676 
WUUS54 KOUN 150639
SVROUN
OKC027-081-125-133-150730-
/O.NEW.KOUN.SV.W.0539.211015T0639Z-211015T0730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
139 AM CDT Fri Oct 15 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Northern Seminole County in east central Oklahoma...
  Southeastern Lincoln County in central Oklahoma...
  East central Cleveland County in central Oklahoma...
  Northern Pottawatomie County in central Oklahoma...

* Until 230 AM CDT.

* At 138 AM CDT, severe thunderstorms were located along a line
  extending from 3 miles west of Prague to near Tecumseh to near
  Etowah, moving east at 40 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...
  Southeastern Norman, Shawnee, Seminole, Tecumseh, Prague, Pink,
  Meeker, Maud, Earlsboro, Bowlegs, Tribbey, Cromwell, Johnson,
  Etowah, Brooksville, Macomb, Little, Bethel Acres, Lima and
  Aydelotte.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3510 9669 3512 9729 3534 9706 3555 9678
      3556 9662 3540 9662 3539 9661 3541 9659
      3539 9655 3539 9653 3544 9657 3545 9655
      3546 9654 3543 9651 3543 9649 3546 9648
      3545 9644 3532 9644
TIME...MOT...LOC 0638Z 264DEG 34KT 3548 9675 3530 9693 3511 9720 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

30

2 follow-up statements

746 
WWUS54 KOUN 150702
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
202 AM CDT Fri Oct 15 2021

OKC027-150712-
/O.CAN.KOUN.SV.W.0539.000000T0000Z-211015T0730Z/
Cleveland OK-
202 AM CDT Fri Oct 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL CLEVELAND COUNTY
IS CANCELLED...

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

LAT...LON 3510 9669 3512 9714 3533 9695 3555 9671
      3556 9662 3540 9662 3539 9661 3541 9659
      3539 9655 3539 9653 3544 9657 3545 9655
      3546 9654 3543 9651 3543 9649 3546 9648
      3545 9644 3532 9644
TIME...MOT...LOC 0702Z 259DEG 31KT 3542 9660 3528 9674 3516 9699 

$$

OKC081-125-133-150730-
/O.CON.KOUN.SV.W.0539.000000T0000Z-211015T0730Z/
Seminole OK-Lincoln OK-Pottawatomie OK-
202 AM CDT Fri Oct 15 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 230 AM CDT
FOR NORTHERN SEMINOLE...SOUTHEASTERN LINCOLN AND CENTRAL POTTAWATOMIE
COUNTIES...

At 202 AM CDT, severe thunderstorms were located along a line
extending from 6 miles northeast of Little to 3 miles east of
Earlsboro to near Macomb, moving east at 35 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...
Shawnee, Seminole, Tecumseh, Prague, Maud, Earlsboro, Bowlegs,
Tribbey, Cromwell, Johnson, Brooksville, Macomb, Little, Lima,
Centerview and Harjo.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3510 9669 3512 9714 3533 9695 3555 9671
      3556 9662 3540 9662 3539 9661 3541 9659
      3539 9655 3539 9653 3544 9657 3545 9655
      3546 9654 3543 9651 3543 9649 3546 9648
      3545 9644 3532 9644
TIME...MOT...LOC 0702Z 259DEG 31KT 3542 9660 3528 9674 3516 9699 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

30

867 
WWUS54 KOUN 150727
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
227 AM CDT Fri Oct 15 2021

OKC081-125-133-150736-
/O.EXP.KOUN.SV.W.0539.000000T0000Z-211015T0730Z/
Seminole OK-Lincoln OK-Pottawatomie OK-
227 AM CDT Fri Oct 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN SEMINOLE...
SOUTHEASTERN LINCOLN AND CENTRAL POTTAWATOMIE COUNTIES WILL EXPIRE AT
230 AM CDT...
    
The storms which prompted the warning have exited the warned area. 
Therefore, the warning will be allowed to expire. However gusty 
winds and heavy rain are still possible with these thunderstorms.

LAT...LON 3510 9669 3512 9714 3533 9695 3555 9671
      3556 9662 3540 9662 3539 9661 3541 9659
      3539 9655 3539 9653 3544 9657 3545 9655
      3546 9654 3543 9651 3543 9649 3546 9648
      3545 9644 3532 9644
TIME...MOT...LOC 0726Z 259DEG 35KT 3544 9634 3534 9646 3522 9673 

$$

11

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 14, 10:42 PM CDT	Special Weather Statement	OUN	Canadian	33 min
Oct 14, 11:04 PM CDT	Special Weather Statement	OUN	Kiowa	26 min
Oct 14, 11:17 PM CDT	Special Weather Statement	OUN	Canadian	28 min
Oct 14, 11:45 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Cleveland, Grady, McClain, Oklahoma	45 min
Oct 15, 12:12 AM CDT	Severe Thunderstorm Warning Considerable damage threat	OUN	Cleveland, McClain, Oklahoma	48 min
Oct 15, 12:33 AM CDT	Special Weather Statement	OUN	Cleveland	27 min
Oct 15, 12:43 AM CDT	Areal Flood Advisory	OUN	Canadian, Cleveland, Grady, McClain, Oklahoma	3 hr
Oct 15, 12:46 AM CDT	Special Weather Statement	OUN	Grady	29 min
Oct 15, 12:54 AM CDT	Severe Thunderstorm Warning	OUN	Lincoln, Oklahoma, Pottawatomie	51 min
Oct 15, 1:09 AM CDT	Special Weather Statement	OUN	Cleveland, McClain	36 min
Oct 15, 2:30 AM CDT	Special Weather Statement	OUN	Seminole	45 min
Oct 15, 3:13 AM CDT	Special Weather Statement	OUN	Hughes	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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.