Alert archive / Texas / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 179, NWS Austin/San Antonio, TX

September 6, 20214 counties in Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Sep 6, 2021, 4:17 PM CDT for 4 counties in Texas. It was in force for 58 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
Sep 6, 2021, 4:17 PM CDT (21:17 UTC)
Expired
Sep 6, 2021, 5:15 PM CDT
In force
58 min
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Caldwell County, TX, Comal County, TX, Guadalupe County, TX, Hays County, TX

The radar

The Austin/San Antonio radar (KEWX), 37 km from the middle of the area, began a volume at 21:21 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, 9.3 hours before the alert went out and 261 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, Corpus Christi, TX at 12:00Z on 2021-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1100 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, Corpus Christi, TX at 12:00Z on 2021-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -58 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
1100 J/kg
Mixed-layer CIN
-120 J/kg
Mixed-layer LCL
1099 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-58 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

095 
WUUS54 KEWX 062117
SVREWX
TXC055-091-187-209-062215-
/O.NEW.KEWX.SV.W.0179.210906T2117Z-210906T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Austin/San Antonio TX
417 PM CDT Mon Sep 6 2021

The National Weather Service in Austin San Antonio has issued a

* Severe Thunderstorm Warning for...
  Northwestern Caldwell County in south central Texas...
  Hays County in south central Texas...
  North central Guadalupe County in south central Texas...
  Northeastern Comal County in south central Texas...

* Until 515 PM CDT.

* At 417 PM CDT, a severe thunderstorm was located near Buda, moving
  southwest at 20 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...
  San Marcos, Kyle, Buda, Dripping Springs, Wimberley, Canyon Lake
  Dam, Canyon Lake, Woodcreek, Martindale, Uhland, Mustang Ridge,
  Niederwald, Bear Creek, Zorn, Driftwood, Manchaca, Mountain City,
  Hays, Hunter 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 3016 9789 3003 9772 3003 9770 2973 9796
      2986 9830 3021 9798
TIME...MOT...LOC 2117Z 031DEG 19KT 3006 9790 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MO

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 5, 8:21 PM CDTAreal Flood AdvisoryEWXWilliamson2 hr
Sep 6, 2:32 PM CDTSpecial Weather StatementEWXGuadalupe28 min
Sep 6, 3:01 PM CDTSpecial Weather StatementEWXGuadalupe44 min
Sep 6, 3:03 PM CDTSpecial Weather StatementEWXBastrop42 min
Sep 6, 3:45 PM CDTSpecial Weather StatementEWXCaldwell, Fayette, Hays, Travis45 min
Sep 6, 3:47 PM CDTSpecial Weather StatementEWXBexar, Guadalupe43 min
Sep 6, 3:50 PM CDTSpecial Weather StatementEWXKendall55 min
Sep 6, 4:24 PM CDTSpecial Weather StatementEWXKendall51 min
Sep 6, 4:35 PM CDTSpecial Weather StatementEWXBandera, Edwards, Kinney, Medina, Real, Uvalde55 min
Sep 6, 4:39 PM CDTSpecial Weather StatementEWXBexar66 min
Sep 6, 4:51 PM CDTAreal Flood AdvisoryEWXBandera, Bexar, Comal, Kendall, Kerr, Medina3 hr
Sep 6, 5:02 PM CDTSpecial Weather StatementEWXHays58 min
Sep 6, 5:06 PM CDTSpecial Weather StatementEWXGonzales, Lavaca54 min
Sep 6, 5:19 PM CDTAreal Flood AdvisoryEWXBlanco, Comal, Hays, Kendall3 hr
Sep 6, 5:35 PM CDTSpecial Weather StatementEWXBlanco40 min
Sep 6, 6:19 PM CDTFlash Flood Warning Considerable damage threatEWXBlanco3 hr

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.