Alert archive / Texas / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 921, NWS Norman, OK

October 21, 2017Archer County, Clay County, Texas

NWS Norman, OK issued this severe thunderstorm warning at Oct 21, 2017, 9:49 PM CDT for Archer County, Clay County, Texas. It was in force for 41 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
Oct 21, 2017, 9:49 PM CDT (02:49 UTC)
Expired
Oct 21, 2017, 10:30 PM CDT
In force
41 min
Issued by
NWS Norman, OK
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Archer County, TX, Clay County, TX

The radar

The Altus AFB radar (KFDR), 110 km from the middle of the area, began a volume at 02:52 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Oct 21, 3:06 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 2.8 hours before the alert went out and 122 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 00:00Z on 2017-10-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1142 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 00:00Z on 2017-10-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 124 square meters per square second.19395878Sfc1 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
1142 J/kg
Mixed-layer CIN
-102 J/kg
Mixed-layer LCL
1889 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
124 m²/s²
0-3 km storm-relative helicity
180 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.9

Open this sounding in Storm Lab

The text

As transmitted.

079 
WUUS54 KOUN 220249
SVROUN
TXC009-077-220330-
/O.NEW.KOUN.SV.W.0921.171022T0249Z-171022T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Norman OK
949 PM CDT SAT OCT 21 2017

The National Weather Service in Norman has issued a

* Severe Thunderstorm Warning for...
  Southern Clay County in northern Texas...
  Southeastern Archer County in northern Texas...

* Until 1030 PM CDT

* At 949 PM CDT, a severe thunderstorm was located 5 miles south of
  Windthorst, moving northeast at 40 mph.

  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...
  Windthorst, Bellevue, Bluegrove, Vashti, Shannon and Joy. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3352 9855 3391 9799 3388 9798 3350 9798
      3346 9811 3347 9842 3340 9842 3340 9844
TIME...MOT...LOC 0249Z 234DEG 35KT 3350 9842 

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

..speg.
2 follow-up statements
493 
WWUS54 KOUN 220319
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
1019 PM CDT SAT OCT 21 2017

TXC009-220324-
/O.CAN.KOUN.SV.W.0921.000000T0000Z-171022T0330Z/
Archer TX-
1019 PM CDT SAT OCT 21 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN ARCHER COUNTY IS
CANCELLED...

The storms which prompted the warning have moved into Clay County. 
Therefore, the warning has been cancelled for Archer County.

LAT...LON 3391 9799 3388 9798 3350 9798 3346 9811
      3347 9842 3366 9835
TIME...MOT...LOC 0314Z 239DEG 50KT 3365 9819 3348 9824 

$$

TXC077-220330-
/O.CON.KOUN.SV.W.0921.000000T0000Z-171022T0330Z/
Clay TX-
1019 PM CDT SAT OCT 21 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM CDT
FOR SOUTHERN CLAY COUNTY...

At 1014 PM CDT, severe thunderstorms were located along a line
extending from near Bluegrove to 12 miles west of Newport, moving
northeast at 55 mph.

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...
Bellevue, Bluegrove, Vashti, Shannon and Joy. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3391 9799 3388 9798 3350 9798 3346 9811
      3347 9842 3366 9835
TIME...MOT...LOC 0314Z 239DEG 50KT 3365 9819 3348 9824 

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

..speg.
381 
WWUS54 KOUN 220321
SVSOUN

Severe Weather Statement
National Weather Service Norman OK
1021 PM CDT SAT OCT 21 2017

TXC077-220330-
/O.EXP.KOUN.SV.W.0921.000000T0000Z-171022T0330Z/
Clay TX-
1021 PM CDT SAT OCT 21 2017

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN CLAY COUNTY WILL
EXPIRE AT 1030 PM CDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning will be allowed to expire.  However gusty winds
are still possible with these thunderstorms.

LAT...LON 3391 9799 3388 9798 3350 9798 3346 9811
      3347 9842 3366 9835
TIME...MOT...LOC 0320Z 234DEG 35KT 3368 9813 3351 9818 

$$

KURTZ

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 21, 7:09 PM CDTSevere Thunderstorm WarningOUNWilbarger36 min
Oct 21, 7:10 PM CDTSevere Thunderstorm WarningOUNWichita, Wilbarger50 min
Oct 21, 7:50 PM CDTSpecial Weather StatementOUNFoard, Knox25 min
Oct 21, 7:59 PM CDTSevere Thunderstorm WarningOUNClay, Wichita, Wilbarger46 min
Oct 21, 8:01 PM CDTSevere Thunderstorm WarningOUNFoard, Knox29 min
Oct 21, 8:10 PM CDTSevere Thunderstorm WarningOUNKnox35 min
Oct 21, 8:20 PM CDTSevere Thunderstorm WarningOUNBaylor, Foard, Knox, Wilbarger40 min
Oct 21, 8:57 PM CDTSevere Thunderstorm WarningOUNArcher, Baylor, Knox, Wichita, Wilbarger48 min
Oct 21, 9:17 PM CDTAreal Flood AdvisoryOUNArcher, Baylor, Clay, Wichita, Wilbarger118 min
Oct 21, 9:34 PM CDTSpecial Weather StatementOUNClay26 min

Nearby

Severe Thunderstorm Warnings in Texas, 2017Every severe thunderstorm warning in 2017

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.