Alert archive / Texas / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 178, NWS Austin/San Antonio, TX
NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Aug 18, 2021, 8:32 PM CDT for Blanco County, Comal County, Kendall County, 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
- Aug 18, 2021, 8:32 PM CDT (01:32 UTC)
- Expired
- Aug 18, 2021, 9:30 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 Blanco County, TX, Comal County, TX, Kendall County, TX
The radar
The Austin/San Antonio radar (KEWX), 45 km from the middle of the area, began a volume at 01:35 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 00:00Z, 1.5 hours before the alert went out and 249 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.
- Mixed-layer CAPE
- 4066 J/kg
- Mixed-layer CIN
- -7 J/kg
- Mixed-layer LCL
- 1192 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- 31 m²/s²
- 0-3 km storm-relative helicity
- 106 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
610
WUUS54 KEWX 190132
SVREWX
TXC031-091-259-190230-
/O.NEW.KEWX.SV.W.0178.210819T0132Z-210819T0230Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Austin/San Antonio TX
832 PM CDT Wed Aug 18 2021
The National Weather Service in Austin San Antonio has issued a
* Severe Thunderstorm Warning for...
Southwestern Blanco County in south central Texas...
Northeastern Kendall County in south central Texas...
North central Comal County in south central Texas...
* Until 930 PM CDT.
* At 832 PM CDT, a severe thunderstorm was located over Spring
Branch, or 12 miles south of Blanco, moving north at 5 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...
Canyon Lake, Guadalupe River State Park, Kendalia, Spring Branch,
Twin Sisters and Honey Creek State Natural Area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Large hail, damaging winds, and continuous cloud to ground lightning
are occurring with this storm. Move indoors immediately. Lightning is
one of nature's leading killers. Remember, if you can hear thunder,
you are close enough to be struck by lightning.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3004 9830 3002 9827 2985 9829 2985 9849
3005 9856 3006 9829
TIME...MOT...LOC 0132Z 171DEG 5KT 2992 9841
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
AAT3 follow-up statements
239
WWUS54 KEWX 190201
SVSEWX
Severe Weather Statement
National Weather Service Austin/San Antonio TX
901 PM CDT Wed Aug 18 2021
TXC031-091-259-190230-
/O.CON.KEWX.SV.W.0178.000000T0000Z-210819T0230Z/
Blanco TX-Kendall TX-Comal TX-
901 PM CDT Wed Aug 18 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM CDT
FOR SOUTH CENTRAL BLANCO...EAST CENTRAL KENDALL AND NORTH CENTRAL
COMAL COUNTIES...
At 901 PM CDT, a severe thunderstorm was located near Spring Branch,
or 11 miles south of Blanco, and is nearly stationary.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to
roofs, siding, and trees.
Locations impacted include...
Canyon Lake, Spring Branch, Twin Sisters, Guadalupe River State Park
and Honey Creek State Natural Area.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 2999 9828 2985 9829 2985 9849 3001 9850
3002 9831
TIME...MOT...LOC 0201Z 131DEG 2KT 2994 9842
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
AAT820
WWUS54 KEWX 190217
SVSEWX
Severe Weather Statement
National Weather Service Austin/San Antonio TX
917 PM CDT Wed Aug 18 2021
TXC091-190226-
/O.CAN.KEWX.SV.W.0178.000000T0000Z-210819T0230Z/
Comal TX-
917 PM CDT Wed Aug 18 2021
...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL COMAL COUNTY IS
CANCELLED...
The severe thunderstorm which prompted the warning has weakened and
moved northwest of Comal County. Therefore, the warning has been
cancelled.
LAT...LON 2987 9849 2988 9849 3001 9850 3002 9832
TIME...MOT...LOC 0216Z 131DEG 2KT 2994 9843
$$
TXC031-259-190230-
/O.CON.KEWX.SV.W.0178.000000T0000Z-210819T0230Z/
Blanco TX-Kendall TX-
917 PM CDT Wed Aug 18 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 930 PM CDT
FOR SOUTH CENTRAL BLANCO AND EAST CENTRAL KENDALL COUNTIES...
At 916 PM CDT, a severe thunderstorm was located near Spring Branch,
or 10 miles south of Blanco, and is nearly stationary.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Twin Sisters and Guadalupe River State Park.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 2987 9849 2988 9849 3001 9850 3002 9832
TIME...MOT...LOC 0216Z 131DEG 2KT 2994 9843
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
AAT112
WWUS54 KEWX 190224
SVSEWX
Severe Weather Statement
National Weather Service Austin/San Antonio TX
924 PM CDT Wed Aug 18 2021
TXC031-259-190233-
/O.EXP.KEWX.SV.W.0178.000000T0000Z-210819T0230Z/
Blanco TX-Kendall TX-
924 PM CDT Wed Aug 18 2021
...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL BLANCO AND EAST
CENTRAL KENDALL COUNTIES WILL EXPIRE AT 930 PM CDT...
The severe thunderstorm which prompted the warning has weakened
below severe limits. Therefore, the warning will be allowed to
expire. Heavy rainfall continues over these areas so be aware of
street flooding and while driving in and around low water crossings.
LAT...LON 2987 9849 2988 9849 3001 9850 3002 9832
TIME...MOT...LOC 0223Z 171DEG 5KT 2995 9843
$$
AATThe office that day
Everything else NWS Austin/San Antonio, TX issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 18, 7:06 PM CDT | Special Weather Statement | EWX | Dimmit | 39 min |
| Aug 18, 7:51 PM CDT | Special Weather Statement | EWX | Maverick | 39 min |
| Aug 18, 7:54 PM CDT | Special Weather Statement | EWX | Hays | 51 min |
| Aug 18, 8:25 PM CDT | Special Weather Statement | EWX | Comal | 50 min |
| Aug 18, 9:02 PM CDT | Areal Flood Advisory | EWX | Blanco, Comal, Kendall | 4 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.