Alert archive / Texas / Freeze Warnings in 2021

Freeze Warning 1, NWS Austin/San Antonio, TX

December 11, 202125 counties in Texas

NWS Austin/San Antonio, TX issued this freeze warning at Dec 11, 2021, 1:52 PM CST for 25 counties in Texas. It took effect at Dec 11, 2021, 11:00 PM CST. It was in force for 9 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Dec 11, 2021, 1:52 PM CST (19:52 UTC)
In effect from
Dec 11, 2021, 11:00 PM CST
Expired
Dec 12, 2021, 8:00 AM CST
In force
9 hr
Issued by
NWS Austin/San Antonio, TX
All 25 counties

Bandera County, TX, Bastrop County, TX, Bexar County, TX, Blanco County, TX, Burnet County, TX, Caldwell County, TX, Comal County, TX, Dimmit County, TX, Edwards County, TX, Gillespie County, TX, Guadalupe County, TX, Hays County, TX, Kendall County, TX, Kerr County, TX, Kinney County, TX, Lee County, TX, Llano County, TX, Maverick County, TX, Medina County, TX, Real County, TX, Travis County, TX, Uvalde County, TX, Val Verde County, TX, Williamson County, TX, Zavala County, TX

The radar

The Austin/San Antonio radar (KEWX), 83 km from the middle of the area, began a volume at 19:55 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

Del Rio, TX (KDRT), launched 12:00Z, 7.9 hours before the alert went out and 196 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, Del Rio, TX at 12:00Z on 2021-12-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Del Rio, TX at 12:00Z on 2021-12-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -186 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3017 m above ground
0-6 km bulk shear
77 kt
0-1 km storm-relative helicity
-186 m²/s²
0-3 km storm-relative helicity
-137 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

246 
WWUS74 KEWX 111952
NPWEWX

URGENT - WEATHER MESSAGE
National Weather Service Austin/San Antonio TX
152 PM CST Sat Dec 11 2021

TXZ171>173-184>192-206-120400-
/O.NEW.KEWX.FZ.W.0001.211212T0700Z-211212T1400Z/
Llano-Burnet-Williamson-Edwards-Real-Kerr-Bandera-Gillespie-
Kendall-Blanco-Hays-Travis-Comal-
Including the cities of Llano, Burnet, Georgetown, Rocksprings, 
Leakey, Kerrville, Bandera, Fredericksburg, Boerne, Blanco, 
San Marcos, Austin, and New Braunfels
152 PM CST Sat Dec 11 2021

...FREEZE WARNING IN EFFECT FROM 1 AM TO 8 AM CST SUNDAY...

* WHAT...Sub-freezing temperatures as low as 29 expected.

* WHERE...Portions of south central Texas.

* WHEN...From 1 AM to 8 AM CST Sunday.

* IMPACTS...Frost and freeze conditions will kill or damage crops
  and other sensitive vegetation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. Pipes and
in ground sprinkler systems should be fine since temperatures will
only fall below freezing by a few degrees for a few hours. You can
always be on the safe side by wrapping exposed pipes or draining
water lines before the freezing conditions arrive.

&&

$$
3 follow-up statements
948 
WWUS74 KEWX 120441
NPWEWX

URGENT - WEATHER MESSAGE
National Weather Service Austin/San Antonio TX
1041 PM CST Sat Dec 11 2021

TXZ171>173-184>192-206-121400-
/O.CON.KEWX.FZ.W.0001.211212T0700Z-211212T1400Z/
Llano-Burnet-Williamson-Edwards-Real-Kerr-Bandera-Gillespie-
Kendall-Blanco-Hays-Travis-Comal-
Including the cities of Llano, Burnet, Georgetown, Rocksprings, 
Leakey, Kerrville, Bandera, Fredericksburg, Boerne, Blanco, 
San Marcos, Austin, and New Braunfels
1041 PM CST Sat Dec 11 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM CST SUNDAY...

* WHAT...Sub-freezing temperatures as low as 27 expected.

* WHERE...Portions of south central Texas.

* WHEN...Until 8 AM CST Sunday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$
503 
WWUS74 KEWX 120453
NPWEWX

URGENT - WEATHER MESSAGE
National Weather Service Austin/San Antonio TX
1053 PM CST Sat Dec 11 2021

TXZ171>173-184>192-206-121400-
/O.EXT.KEWX.FZ.W.0001.211212T0500Z-211212T1400Z/
Llano-Burnet-Williamson-Edwards-Real-Kerr-Bandera-Gillespie-
Kendall-Blanco-Hays-Travis-Comal-
Including the cities of Llano, Burnet, Georgetown, Rocksprings, 
Leakey, Kerrville, Bandera, Fredericksburg, Boerne, Blanco, 
San Marcos, Austin, and New Braunfels
1053 PM CST Sat Dec 11 2021

...FREEZE WARNING NOW IN EFFECT UNTIL 8 AM CST SUNDAY...

* WHAT...Sub-freezing temperatures as low as 29 expected.

* WHERE...Portions of south central Texas.

* WHEN...Until 8 AM CST Sunday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$
760 
WWUS74 KEWX 121151
NPWEWX

URGENT - WEATHER MESSAGE
National Weather Service Austin/San Antonio TX
551 AM CST Sun Dec 12 2021

TXZ183-193-194-202>205-207-208-217-218-228-121400-
/O.EXA.KEWX.FZ.W.0001.000000T0000Z-211212T1400Z/
Val Verde-Bastrop-Lee-Kinney-Uvalde-Medina-Bexar-Guadalupe-
Caldwell-Maverick-Zavala-Dimmit-
Including the cities of Del Rio, Bastrop, Giddings, 
Brackettville, Uvalde, Hondo, San Antonio, Seguin, Lockhart, 
Eagle Pass, Crystal City, and Carrizo Springs
551 AM CST Sun Dec 12 2021

...FREEZE WARNING IN EFFECT UNTIL 8 AM CST THIS MORNING...

* WHAT...Sub-freezing temperatures as low as 30.

* WHERE...Portions of south central Texas.

* WHEN...Until 8 AM CST Sunday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

* ADDITIONAL DETAILS...Some areas inside the city of San Antonio,
  Del Rio, and other cities and towns will likely stay above
  freezing. Outlying areas, rural areas, and typical cold spots
  will likely drop below the freezing mark.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

TXZ171>173-184>192-206-121400-
/O.CON.KEWX.FZ.W.0001.000000T0000Z-211212T1400Z/
Llano-Burnet-Williamson-Edwards-Real-Kerr-Bandera-Gillespie-
Kendall-Blanco-Hays-Travis-Comal-
Including the cities of Llano, Burnet, Georgetown, Rocksprings, 
Leakey, Kerrville, Bandera, Fredericksburg, Boerne, Blanco, 
San Marcos, Austin, and New Braunfels
551 AM CST Sun Dec 12 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM CST THIS MORNING...

* WHAT...Sub-freezing temperatures as low as the mid to upper 20s
  can be expected. 

* WHERE...Portions of south central Texas.

* WHEN...Until 8 AM CST Sunday.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

* ADDITIONAL DETAILS...Some low spots may drop into the lower 20s
  in the western Hill Country. Some interior sections of the city
  of Austin may stay above freezing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

Nearby

Freeze Warnings in Texas, 2021Every freeze 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.