Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 460, NWS Norman, OK

August 19, 2021Hardeman County, Texas; Greer County, Harmon County, Jackson County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Aug 19, 2021, 5:28 PM CDT for Hardeman County, Texas; Greer County, Harmon County, Jackson County, Oklahoma. It was in force for 47 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
Aug 19, 2021, 5:28 PM CDT (22:28 UTC)
Expired
Aug 19, 2021, 6:15 PM CDT
In force
47 min
Issued by
NWS Norman, OK
Area
Storm-based polygon
Damage threat
Considerable
Hail
1.0 in
Wind
70.0 mph

Counties Greer County, OK, Harmon County, OK, Jackson County, OK, Hardeman County, TX

The radar

The Altus AFB radar (KFDR), 75 km from the middle of the area, began a volume at 22:30 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

Amarillo Airport, TX (KAMA), launched 12:00Z, 10.5 hours before the alert went out and 192 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-pSkew-T log-p diagram, Amarillo Airport, TX at 12:00Z on 2021-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1123 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Amarillo Airport, TX at 12:00Z on 2021-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
1123 J/kg
Mixed-layer CIN
-57 J/kg
Mixed-layer LCL
988 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
89 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

752 
WUUS54 KOUN 192228
SVROUN
OKC055-057-065-TXC197-192315-
/O.NEW.KOUN.SV.W.0460.210819T2228Z-210819T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
528 PM CDT Thu Aug 19 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Central Jackson County in southwestern Oklahoma...
  Southern Harmon County in southwestern Oklahoma...
  Southeastern Greer County in southwestern Oklahoma...
  Northwestern Hardeman County in northern Texas...

* Until 615 PM CDT.

* At 528 PM CDT, severe thunderstorms were located along a line
  extending from 5 miles west of Mangum to near Duke to 9 miles west
  of Eldorado, moving east at 25 mph.

  HAZARD...70 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* Locations impacted include...
  Altus, Mangum, Eldorado, Martha, Gould, Duke, Altus Air Force Base,
  Hester and McQueen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3467 9989 3490 9974 3486 9938 3464 9928
      3446 9966 3444 9991 3453 9999
TIME...MOT...LOC 2228Z 260DEG 22KT 3486 9961 3469 9955 3452 9980 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

WR
1 follow-up statement
190 
WWUS54 KOUN 192243
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
543 PM CDT Thu Aug 19 2021

OKC055-057-065-TXC197-192315-
/O.CON.KOUN.SV.W.0460.000000T0000Z-210819T2315Z/
Jackson OK-Harmon OK-Greer OK-Hardeman TX-
543 PM CDT Thu Aug 19 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CDT
FOR CENTRAL JACKSON...SOUTHERN HARMON...SOUTH CENTRAL GREER AND
NORTHWESTERN HARDEMAN COUNTIES...

At 543 PM CDT, severe thunderstorms were located along a line
extending from 4 miles south of Mangum to 3 miles east of Duke to 8
miles west of Eldorado, moving east at 25 mph.

HAZARD...70 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Altus, Eldorado, Martha, Gould, Duke, Altus Air Force Base and
McQueen.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3467 9989 3486 9969 3479 9940 3464 9928
      3446 9966 3444 9991 3456 9997
TIME...MOT...LOC 2243Z 279DEG 22KT 3482 9952 3465 9951 3450 9980 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

WR

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 4:59 PM CDTSevere Thunderstorm WarningOUNHardeman31 min
Aug 19, 6:02 PM CDTSevere Thunderstorm Warning Considerable damage threatOUNWilbarger28 min
Aug 19, 6:54 PM CDTSpecial Weather StatementOUNHardeman36 min
Aug 19, 7:38 AM CDTAreal Flood AdvisoryOUNComanche36 min
Aug 19, 8:14 AM CDTFlash Flood WarningOUNComanche3 hr
Aug 19, 3:27 PM CDTSpecial Weather StatementOUNBeckham33 min
Aug 19, 3:29 PM CDTSpecial Weather StatementOUNHarmon31 min
Aug 19, 4:10 PM CDTSpecial Weather StatementOUNBeckham35 min
Aug 19, 5:14 PM CDTSevere Thunderstorm Warning Considerable damage threatOUNGreer, Harmon, Jackson31 min
Aug 19, 6:26 PM CDTSevere Thunderstorm Warning Considerable damage threatOUNJackson, Tillman34 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2021Severe Thunderstorm Warnings in Texas, 2021Every 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.