Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 438, NWS Norman, OK

July 31, 2021Grant County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Jul 31, 2021, 6:59 PM CDT for Grant County, Oklahoma. It was in force for 15 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: Jul 31, 2021, 6:59 PM CDT (23:59 UTC)
Expired: Jul 31, 2021, 7:14 PM CDT
In force: 15 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

County Grant County, OK

The radar

The Vance AFB radar (KVNX), 29 km from the middle of the area, began a volume at 00:00 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 12:00Z, 12.0 hours before the alert went out and 212 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: 468 J/kg
Mixed-layer CIN: -148 J/kg
Mixed-layer LCL: 2050 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 39 m²/s²
0-3 km storm-relative helicity: 50 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

634 
WUUS54 KOUN 312359
SVROUN
OKC053-010045-
/O.NEW.KOUN.SV.W.0438.210731T2359Z-210801T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
659 PM CDT Sat Jul 31 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Central Grant County in northern Oklahoma...

* Until 745 PM CDT.

* At 658 PM CDT, a severe thunderstorm was located 5 miles east of
  Wakita, moving south at 5 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Medford and Jefferson. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3689 9791 3694 9776 3674 9760 3668 9792
TIME...MOT...LOC 2358Z 343DEG 5KT 3687 9782 

HAIL...0.88IN
WIND...60MPH
 
$$

JT

1 follow-up statement

706 
WWUS54 KOUN 010014
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
714 PM CDT Sat Jul 31 2021

OKC053-010023-
/O.CAN.KOUN.SV.W.0438.000000T0000Z-210801T0045Z/
Grant OK-
714 PM CDT Sat Jul 31 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL GRANT COUNTY IS
CANCELLED...
                 
The storm which prompted the warning has weakened below severe
limits, therefore the warning has been cancelled.

LAT...LON 3689 9791 3694 9776 3674 9760 3668 9792
TIME...MOT...LOC 0011Z 343DEG 5KT 3685 9781 

$$

JT

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 2:08 PM CDT	Heat Advisory	OUN	Atoka, Bryan	19 hr
Jul 31, 3:48 PM CDT	Severe Thunderstorm Warning	OUN	Woods	42 min
Jul 31, 4:25 PM CDT	Severe Thunderstorm Warning	OUN	Woods	35 min
Jul 31, 4:51 PM CDT	Special Weather Statement	OUN	Harper	24 min
Jul 31, 4:51 PM CDT	Special Weather Statement	OUN	Woods	24 min
Jul 31, 4:57 PM CDT	Severe Thunderstorm Warning	OUN	Woods, Woodward	35 min
Jul 31, 5:03 PM CDT	Special Weather Statement	OUN	Kay	27 min
Jul 31, 5:35 PM CDT	Special Weather Statement	OUN	Kay	25 min
Jul 31, 5:52 PM CDT	Special Weather Statement	OUN	Woods	23 min
Jul 31, 5:57 PM CDT	Special Weather Statement	OUN	Woodward	33 min
Jul 31, 6:03 PM CDT	Special Weather Statement	OUN	Grant	27 min
Jul 31, 6:15 PM CDT	Special Weather Statement	OUN	Harper	30 min
Jul 31, 6:29 PM CDT	Special Weather Statement	OUN	Woods	31 min
Jul 31, 6:34 PM CDT	Severe Thunderstorm Warning	OUN	Grant	41 min
Jul 31, 6:41 PM CDT	Special Weather Statement	OUN	Harper	34 min
Jul 31, 6:48 PM CDT	Special Weather Statement	OUN	Woods	27 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.