Alert archive / Texas / Special Weather Statements in 2021

Special Weather Statement, NWS Austin/San Antonio, TX

July 21, 2021Llano County, Texas

NWS Austin/San Antonio, TX issued this special weather statement at Jul 21, 2021, 8:11 PM CDT for Llano County, Texas. It was in force for 34 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 21, 2021, 8:11 PM CDT (01:11 UTC)
Expired
Jul 21, 2021, 8:45 PM CDT
In force
34 min
Issued by
NWS Austin/San Antonio, TX

County Llano County, TX

The radar

The Ft Hood radar (KGRK), 111 km from the middle of the area, began a volume at 01:13 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 00:00Z, 1.2 hours before the alert went out and 257 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 2021-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 144 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 2021-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 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
144 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
1882 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

976 
WWUS84 KEWX 220111
SPSEWX

Special Weather Statement
National Weather Service Austin/San Antonio TX
811 PM CDT Wed Jul 21 2021
 
TXZ171-220145-
Llano TX-
811 PM CDT Wed Jul 21 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN LLANO COUNTY UNTIL
845 PM CDT...

At 810 PM CDT, Doppler radar was tracking a strong thunderstorm over
Stolz, or near Llano. This storm was nearly stationary.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Bluffton, Stolz, Lone Grove and Tow. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3071 9847 3071 9862 3087 9868 3089 9846
TIME...MOT...LOC 0110Z 172DEG 2KT 3076 9857 

$$

RUNYEN

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 7:21 PM CDTSpecial Weather StatementEWXAtascosa24 min
Jul 21, 7:29 PM CDTAreal Flood AdvisoryEWXAtascosa, Karnes2 hr
Jul 21, 8:01 PM CDTAreal Flood AdvisoryEWXLlano3 hr
Jul 21, 9:36 PM CDTAreal Flood AdvisoryEWXLlano114 min
Jul 22, 3:20 PM CDTSpecial Weather StatementEWXComal, Guadalupe25 min
Jul 22, 3:51 PM CDTSpecial Weather StatementEWXAtascosa24 min
Jul 22, 3:55 PM CDTSpecial Weather StatementEWXHays35 min
Jul 22, 4:15 PM CDTSpecial Weather StatementEWXBexar, Wilson45 min
Jul 22, 4:17 PM CDTSpecial Weather StatementEWXHays28 min
Jul 22, 4:22 PM CDTSpecial Weather StatementEWXAtascosa53 min
Jul 22, 4:42 PM CDTSpecial Weather StatementEWXTravis33 min
Jul 22, 4:51 PM CDTSpecial Weather StatementEWXUvalde39 min
Jul 22, 4:58 PM CDTSpecial Weather StatementEWXBexar47 min
Jul 22, 5:12 PM CDTSpecial Weather StatementEWXDeWitt33 min
Jul 22, 5:18 PM CDTSpecial Weather StatementEWXFrio, Guadalupe, Wilson42 min
Jul 22, 5:28 PM CDTAreal Flood AdvisoryEWXAtascosa, Bexar, Wilson3 hr
Jul 22, 5:42 PM CDTSpecial Weather StatementEWXGonzales48 min

Nearby

Special Weather Statements in Texas, 2021Every special weather statement 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.