Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 340, NWS Norman, OK

June 20, 2021Harper County, Woodward County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Jun 20, 2021, 8:29 PM CDT for Harper County, Woodward County, Oklahoma. It was in force for 31 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: Jun 20, 2021, 8:29 PM CDT (01:29 UTC)
Expired: Jun 20, 2021, 9:00 PM CDT
In force: 31 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Harper County, OK, Woodward County, OK

The radar

The Vance AFB radar (KVNX), 109 km from the middle of the area, began a volume at 01:29 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

Dodge City, (KDDC), launched 00:00Z, 1.5 hours before the alert went out and 143 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: 375 J/kg
Mixed-layer CIN: -333 J/kg
Mixed-layer LCL: 2510 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 170 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

657 
WUUS54 KOUN 210129
SVROUN
OKC059-153-210215-
/O.NEW.KOUN.SV.W.0340.210621T0129Z-210621T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
829 PM CDT Sun Jun 20 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Southeastern Harper County in northwestern Oklahoma...
  Central Woodward County in northwestern Oklahoma...

* Until 915 PM CDT.

* At 828 PM CDT, a severe thunderstorm was located 12 miles southwest
  of Alabaster Caverns State Park, moving southeast at 10 mph. Damaging
  winds will be the primary concern.

  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...
  Woodward and Mooreland. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3661 9949 3674 9932 3655 9900 3633 9936
TIME...MOT...LOC 0128Z 319DEG 9KT 3663 9935 

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

11

3 follow-up statements

200 
WWUS54 KOUN 210143
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
843 PM CDT Sun Jun 20 2021

OKC059-210152-
/O.CAN.KOUN.SV.W.0340.000000T0000Z-210621T0215Z/
Harper OK-
843 PM CDT Sun Jun 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN HARPER 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 3653 9904 3633 9936 3659 9945 3660 9919
TIME...MOT...LOC 0142Z 319DEG 9KT 3660 9932 

$$

OKC153-210215-
/O.CON.KOUN.SV.W.0340.000000T0000Z-210621T0215Z/
Woodward OK-
843 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT
FOR CENTRAL WOODWARD COUNTY...

At 842 PM CDT, a severe thunderstorm was located 11 miles southwest
of Alabaster Caverns State Park, moving southeast at 10 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Woodward and Mooreland. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3653 9904 3633 9936 3659 9945 3660 9919
TIME...MOT...LOC 0142Z 319DEG 9KT 3660 9932 

HAIL...0.75IN
WIND...60MPH
 
$$

11

464 
WWUS54 KOUN 210152
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
852 PM CDT Sun Jun 20 2021

OKC153-210215-
/O.CON.KOUN.SV.W.0340.000000T0000Z-210621T0215Z/
Woodward OK-
852 PM CDT Sun Jun 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT
FOR CENTRAL WOODWARD COUNTY...

At 852 PM CDT, a severe thunderstorm was located 11 miles northwest
of Mooreland, moving southeast at 10 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Mooreland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3636 9931 3659 9938 3660 9928 3660 9923
      3648 9912
TIME...MOT...LOC 0152Z 319DEG 9KT 3658 9930 

HAIL...<.75IN
WIND...60MPH
 
$$

11

725 
WWUS54 KOUN 210200
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
900 PM CDT Sun Jun 20 2021

OKC153-210210-
/O.CAN.KOUN.SV.W.0340.000000T0000Z-210621T0215Z/
Woodward OK-
900 PM CDT Sun Jun 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL WOODWARD COUNTY IS
CANCELLED...
                 
The storm which prompted the warning has weakened below severe
limits, therefore the warning has been cancelled.  However gusty
winds are still possible with this thunderstorm.

LAT...LON 3636 9931 3659 9938 3660 9928 3660 9923
      3648 9912
TIME...MOT...LOC 0157Z 319DEG 9KT 3656 9928 

$$

11

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 20, 7:27 PM CDT	Special Weather Statement	OUN	Harper	33 min
Jun 20, 7:44 PM CDT	Special Weather Statement	OUN	Woodward	31 min
Jun 20, 7:53 PM CDT	Special Weather Statement	OUN	Ellis	37 min
Jun 20, 8:11 PM CDT	Special Weather Statement	OUN	Woodward	34 min
Jun 20, 8:31 PM CDT	Special Weather Statement	OUN	Woods	29 min
Jun 21, 3:52 AM CDT	Special Weather Statement	OUN	Woods	38 min
Jun 21, 4:25 AM CDT	Special Weather Statement	OUN	Alfalfa	50 min
Jun 21, 5:17 AM CDT	Special Weather Statement	OUN	Harper, Woods	43 min
Jun 21, 5:32 AM CDT	Special Weather Statement	OUN	Garfield, Grant, Kay, Noble	43 min
Jun 21, 5:58 AM CDT	Special Weather Statement	OUN	Major, Woodward	47 min
Jun 21, 6:22 AM CDT	Special Weather Statement	OUN	Noble	23 min
Jun 21, 7:57 AM CDT	Special Weather Statement	OUN	Roger Mills	33 min
Jun 21, 9:23 AM CDT	Special Weather Statement	OUN	Grady	22 min
Jun 21, 9:40 AM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Grady, McClain	50 min
Jun 21, 9:45 AM CDT	Special Weather Statement	OUN	Canadian	30 min
Jun 21, 10:15 AM CDT	Special Weather Statement	OUN	Murray	30 min
Jun 21, 10:15 AM CDT	Special Weather Statement	OUN	Jackson	30 min
Jun 21, 11:10 AM CDT	Special Weather Statement	OUN	Tillman	35 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.