Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 475, NWS Norman, OK

August 29, 20214 counties in Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Aug 29, 2021, 1:57 PM CDT for 4 counties in Oklahoma. It was in force for 48 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 29, 2021, 1:57 PM CDT (18:57 UTC)
Expired
Aug 29, 2021, 2:45 PM CDT
In force
48 min
Issued by
NWS Norman, OK
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Ellis County, OK, Harper County, OK, Woods County, OK, Woodward County, OK

The radar

The Vance AFB radar (KVNX), 106 km from the middle of the area, began a volume at 18:59 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, 7.0 hours before the alert went out and 120 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, Dodge City, at 12:00Z on 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 560 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, Dodge City, at 12:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 338 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
560 J/kg
Mixed-layer CIN
-245 J/kg
Mixed-layer LCL
1248 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
338 m²/s²
0-3 km storm-relative helicity
439 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

466 
WUUS54 KOUN 291857
SVROUN
OKC045-059-151-153-291945-
/O.NEW.KOUN.SV.W.0475.210829T1857Z-210829T1945Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
157 PM CDT Sun Aug 29 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Northwestern Ellis County in northwestern Oklahoma...
  Northwestern Woods County in northwestern Oklahoma...
  Harper County in northwestern Oklahoma...
  Northern Woodward County in northwestern Oklahoma...

* Until 245 PM CDT.

* At 156 PM CDT, severe thunderstorms were located along a line
  extending from 9 miles northwest of Avard to 4 miles southwest of
  Laverne, moving south at 10 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Laverne, Buffalo, Waynoka, Fort Supply, Freedom, May, Rosston,
  Alabaster Caverns State Park, Selman, Catesby and Camp Houston.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with the storms around Buffalo, 
Rosston, and Laverne and may lead to flooding. Do not drive your 
vehicle through flooded roadways.

&&

LAT...LON 3700 9889 3657 9881 3642 10000 3700 10000
TIME...MOT...LOC 1856Z 016DEG 10KT 3677 9893 3665 9994 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

WR

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 1:11 PM CDTSpecial Weather StatementOUNWoods34 min
Aug 29, 1:26 PM CDTSevere Thunderstorm Warning Considerable damage threatOUNHarper, Woods, Woodward34 min
Aug 29, 2:32 PM CDTAreal Flood AdvisoryOUNHarper3 hr
Aug 29, 2:47 PM CDTSpecial Weather StatementOUNHarper, Woods, Woodward28 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 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.