Alert archive / Texas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 193, NWS Austin/San Antonio, TX

December 18, 20214 counties in Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Dec 18, 2021, 8:27 AM CST for 4 counties in Texas. It was in force for 13 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: Dec 18, 2021, 8:27 AM CST (14:27 UTC)
Expired: Dec 18, 2021, 8:40 AM CST
In force: 13 min
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Bastrop County, TX, Caldwell County, TX, Hays County, TX, Travis County, TX

The radar

The Austin/San Antonio radar (KEWX), 38 km from the middle of the area, began a volume at 14:27 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

Corpus Christi, TX (KCRP), launched 12:00Z, 2.5 hours before the alert went out and 246 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: 2358 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 531 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 172 m²/s²
0-3 km storm-relative helicity: 111 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 5.5

Open this sounding in Storm Lab

The text

As transmitted.

709 
WUUS54 KEWX 181427
SVREWX
TXC021-055-209-453-181515-
/O.NEW.KEWX.SV.W.0193.211218T1427Z-211218T1515Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Austin/San Antonio TX
827 AM CST Sat Dec 18 2021

The National Weather Service in Austin San Antonio has issued a

* Severe Thunderstorm Warning for...
  Northwestern Caldwell County in south central Texas...
  Southeastern Hays County in south central Texas...
  Southeastern Travis County in south central Texas...
  Southwestern Bastrop County in south central Texas...

* Until 915 AM CST.

* At 826 AM CST, a severe thunderstorm was located near Uhland, or
  near Kyle, moving east at 30 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  San Marcos, Kyle, Buda, Lockhart, Martindale, Uhland, Mustang
  Ridge, Niederwald, Cedar Creek, Wyldwood, Mountain City, Creedmoor,
  Rockne, Watterson, Maha, Maxwell, Reedville, Red Rock, Lytton
  Springs and San Marcos Regional Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2994 9731 2982 9784 2983 9784 2985 9786
      2985 9789 2984 9790 3000 9800 3018 9755
TIME...MOT...LOC 1426Z 247DEG 26KT 2992 9785 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

KCW

1 follow-up statement

401 
WWUS54 KEWX 181440
SVSEWX

Severe Weather Statement
National Weather Service Austin/San Antonio TX
840 AM CST Sat Dec 18 2021

TXC021-055-209-453-181450-
/O.CAN.KEWX.SV.W.0193.000000T0000Z-211218T1515Z/
Caldwell TX-Hays TX-Travis TX-Bastrop TX-
840 AM CST Sat Dec 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN CALDWELL...
SOUTHEASTERN HAYS...SOUTHEASTERN TRAVIS AND SOUTHWESTERN BASTROP
COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However small hail is
still possible with this thunderstorm.

LAT...LON 2994 9731 2982 9784 2983 9784 2985 9786
      2985 9789 2984 9790 3000 9800 3018 9755
TIME...MOT...LOC 1436Z 247DEG 26KT 2996 9774 

$$

KCW

The office that day

Everything else NWS Austin/San Antonio, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 18, 2:04 AM CST	Special Weather Statement	EWX	Williamson	41 min
Dec 18, 2:48 AM CST	Special Weather Statement	EWX	Williamson	42 min
Dec 18, 4:59 AM CST	Special Weather Statement	EWX	Williamson	16 min
Dec 18, 5:28 AM CST	Special Weather Statement	EWX	Burnet	47 min
Dec 18, 6:07 AM CST	Special Weather Statement	EWX	Burnet	53 min
Dec 18, 7:34 AM CST	Areal Flood Advisory	EWX	Travis, Williamson	3 hr
Dec 18, 8:14 AM CST	Special Weather Statement	EWX	Caldwell	46 min
Dec 18, 9:11 AM CST	Special Weather Statement	EWX	Bexar	49 min
Dec 18, 9:30 AM CST	Special Weather Statement	EWX	Real	45 min
Dec 18, 9:55 AM CST	Special Weather Statement	EWX	Wilson	50 min
Dec 18, 10:03 AM CST	Special Weather Statement	EWX	Uvalde	42 min
Dec 18, 10:05 AM CST	Special Weather Statement	EWX	Kinney	40 min
Dec 18, 10:09 AM CST	Severe Thunderstorm Warning	EWX	Wilson	36 min
Dec 18, 10:21 AM CST	Severe Thunderstorm Warning	EWX	Bandera, Medina, Uvalde	39 min
Dec 18, 10:25 AM CST	Severe Thunderstorm Warning	EWX	Gonzales, Guadalupe, Wilson	35 min
Dec 18, 10:49 AM CST	Severe Thunderstorm Warning	EWX	Bandera, Medina	41 min
Dec 18, 12:20 PM CST	Special Weather Statement	EWX	Goliad	40 min
Dec 18, 12:38 PM CST	Special Weather Statement	EWX	DeWitt	52 min

Nearby

Severe Thunderstorm Warnings in Texas, 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.