Alert archive / Texas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 415, NWS Norman, OK

July 18, 2021Archer County, Texas

NWS Norman, OK issued this severe thunderstorm warning at Jul 18, 2021, 5:27 PM CDT for Archer County, Texas. It was in force for 33 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 18, 2021, 5:27 PM CDT (22:27 UTC)
Expired
Jul 18, 2021, 6:00 PM CDT
In force
33 min
Issued by
NWS Norman, OK
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Archer County, TX

The radar

The Altus AFB radar (KFDR), 88 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

Fort Worth, TX (KFWD), launched 12:00Z, 10.5 hours before the alert went out and 161 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, Fort Worth, TX at 12:00Z on 2021-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 241 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, Fort Worth, TX at 12:00Z on 2021-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 square meters per square second.1939Sfc1 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
241 J/kg
Mixed-layer CIN
-101 J/kg
Mixed-layer LCL
1347 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-23 m²/s²
0-3 km storm-relative helicity
15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

007 
WUUS54 KOUN 182227
SVROUN
TXC009-182300-
/O.NEW.KOUN.SV.W.0415.210718T2227Z-210718T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
527 PM CDT Sun Jul 18 2021

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Southwestern Archer County in northern Texas...

* Until 600 PM CDT.

* At 527 PM CDT, severe thunderstorms were located along a line
  extending from 5 miles east of Lake Kickapoo to 7 miles west of
  Archer City, and are nearly stationary.

  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...
  Lake Kickapoo.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3367 9884 3342 9887 3345 9865 3372 9864
TIME...MOT...LOC 2227Z 023DEG 3KT 3365 9873 3357 9875 

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

..speg.
1 follow-up statement
239 
WWUS54 KOUN 182305
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
605 PM CDT Sun Jul 18 2021

TXC009-182315-
/O.EXP.KOUN.SV.W.0415.000000T0000Z-210718T2300Z/
Archer TX-
605 PM CDT Sun Jul 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN ARCHER COUNTY HAS
EXPIRED...
             
The storms which prompted the warning have weakened below severe
limits, therefore the warning has been allowed to expire.  However
gusty winds are still possible with these thunderstorms.

LAT...LON 3367 9884 3342 9887 3345 9865 3372 9864
TIME...MOT...LOC 2305Z 023DEG 3KT 3362 9874 3354 9876 

$$

..speg.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 17, 7:12 PM CDTAreal Flood AdvisoryOUNArcher, Clay, Wichita3 hr
Jul 17, 7:41 PM CDTSpecial Weather StatementOUNWilbarger49 min
Jul 17, 9:17 PM CDTSpecial Weather StatementOUNKnox28 min
Jul 18, 5:19 PM CDTSpecial Weather StatementOUNArcher26 min

Nearby

Severe 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.