Alert archive / Texas / Flash Flood Watches in 2021

Flash Flood Watch 2, NWS Austin/San Antonio, TX

May 17, 202125 counties in Texas

NWS Austin/San Antonio, TX issued this flash flood watch at May 17, 2021, 2:34 PM CDT for 25 counties in Texas. It took effect at May 17, 2021, 7:00 PM CDT. It was in force for 50 hr.

The area

The counties it named.

The facts

Issued
May 17, 2021, 2:34 PM CDT (19:34 UTC)
In effect from
May 17, 2021, 7:00 PM CDT
Expired
May 19, 2021, 9:22 PM CDT
In force
50 hr
Issued by
NWS Austin/San Antonio, TX
Flood severity
None
All 25 counties

Atascosa County, TX, Bandera County, TX, Bastrop County, TX, Bexar County, TX, Blanco County, TX, Burnet County, TX, Caldwell County, TX, Comal County, TX, DeWitt County, TX, Fayette County, TX, Frio County, TX, Gillespie County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Karnes County, TX, Kendall County, TX, Kerr County, TX, Lavaca County, TX, Lee County, TX, Llano County, TX, Medina County, TX, Travis County, TX, Williamson County, TX, Wilson County, TX

The radar

The Austin/San Antonio radar (KEWX), 14 km from the middle of the area, began a volume at 19:36 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, 7.6 hours before the alert went out and 242 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 2021-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2756 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Corpus Christi, TX at 12:00Z on 2021-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.193958Sfc1 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
2756 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
515 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.9

Open this sounding in Storm Lab

The text

As transmitted.

516 
WGUS64 KEWX 171934
FFAEWX

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Austin/San Antonio TX
234 PM CDT Mon May 17 2021

.A series of upper level disturbances will move across Texas where 
there will be warm, moist air near the surface. This will cause 
multiple rounds of showers and thunderstorms starting tonight and 
continuing through Thursday morning across South Central Texas. The 
deep moisture will allow some storms to produce locally heavy rain 
that will lead to flash flooding.

TXZ171>173-186>194-204>209-219>225-180745-
/O.NEW.KEWX.FF.A.0002.210518T0000Z-210520T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Llano-Burnet-Williamson-Kerr-Bandera-Gillespie-Kendall-Blanco-Hays-
Travis-Bastrop-Lee-Medina-Bexar-Comal-Guadalupe-Caldwell-Fayette-
Frio-Atascosa-Wilson-Karnes-Gonzales-De Witt-Lavaca-
Including the cities of La Grange, Blanco, Floresville, Gonzales, 
Burnet, New Braunfels, Pearsall, Georgetown, Hondo, Cuero, Seguin, 
San Antonio, Kerrville, Giddings, Hallettsville, Austin, Lockhart, 
Boerne, Karnes City, Llano, Fredericksburg, Pleasanton, Bandera, San 
Marcos, and Bastrop
234 PM CDT Mon May 17 2021

...FLASH FLOOD WATCH IN EFFECT FROM 7 PM CDT THIS EVENING THROUGH 
THURSDAY AFTERNOON...

The National Weather Service in Austin/San Antonio has issued a

* Flash Flood Watch for a portion of south central Texas, including 
  the following areas, Atascosa, Bandera, Bastrop, Bexar, Blanco, 
  Burnet, Caldwell, Comal, De Witt, Fayette, Frio, Gillespie, 
  Gonzales, Guadalupe, Hays, Karnes, Kendall, Kerr, Lavaca, Lee, 
  Llano, Medina, Travis, Williamson and Wilson.

* From 7 PM CDT this evening through Thursday afternoon.

* Highest rainfall totals will be eight to ten inches along I-35 
  from Austin to Jarrell. Outside of this area totals will be two to 
  six inches with some isolated higher amounts.

* The heavy rainfall could lead to flash flooding of low lying 
  buildings, creeks, streams, and roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

BF
5 follow-up statements
491 
WGUS64 KEWX 180745
FFAEWX

Flood Watch
National Weather Service Austin/San Antonio TX
245 AM CDT Tue May 18 2021

.An upper level disturbance will combine with an unseasonably moist
airmass to generate multiple rounds of showers and thunderstorms 
today through Thursday across South Central Texas. Locally heavy
rains can be expected and will lead to flash flooding.

TXZ171>173-186>194-204>209-219>225-182000-
/O.CON.KEWX.FF.A.0002.000000T0000Z-210520T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Llano-Burnet-Williamson-Kerr-Bandera-Gillespie-Kendall-Blanco-
Hays-Travis-Bastrop-Lee-Medina-Bexar-Comal-Guadalupe-Caldwell-
Fayette-Frio-Atascosa-Wilson-Karnes-Gonzales-De Witt-Lavaca-
Including the cities of Llano, Burnet, Georgetown, Kerrville, 
Bandera, Fredericksburg, Boerne, Blanco, San Marcos, Austin, 
Bastrop, Giddings, Hondo, San Antonio, New Braunfels, Seguin, 
Lockhart, La Grange, Pearsall, Pleasanton, Floresville, 
Karnes City, Gonzales, Cuero, and Hallettsville
245 AM CDT Tue May 18 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY
AFTERNOON...

The Flash Flood Watch continues for

* A portion of south central Texas, including the following 
  areas, Atascosa, Bandera, Bastrop, Bexar, Blanco, Burnet, 
  Caldwell, Comal, De Witt, Fayette, Frio, Gillespie, Gonzales, 
  Guadalupe, Hays, Karnes, Kendall, Kerr, Lavaca, Lee, Llano, 
  Medina, Travis, Williamson, and Wilson. 

* Through Thursday afternoon

* Rainfall totals of 3 to 7 inches are expected with isolated 
  higher totals up to 10 inches possible. 

* The heavy rainfall could lead to flash flooding of low lying 
  buildings, creeks, streams, and roads. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$
744 
WGUS64 KEWX 181953
FFAEWX

Flood Watch
National Weather Service Austin/San Antonio TX
253 PM CDT Tue May 18 2021

.An upper level disturbance will combine with an unseasonably
moist airmass to generate multiple rounds of showers and
thunderstorms today through Thursday across South Central Texas.
Locally heavy rains can be expected and will lead to flash
flooding.

TXZ171>173-186>194-204>209-219>225-190900-
/O.CON.KEWX.FF.A.0002.000000T0000Z-210520T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Llano-Burnet-Williamson-Kerr-Bandera-Gillespie-Kendall-Blanco-
Hays-Travis-Bastrop-Lee-Medina-Bexar-Comal-Guadalupe-Caldwell-
Fayette-Frio-Atascosa-Wilson-Karnes-Gonzales-De Witt-Lavaca-
Including the cities of Llano, Burnet, Georgetown, Kerrville, 
Bandera, Fredericksburg, Boerne, Blanco, San Marcos, Austin, 
Bastrop, Giddings, Hondo, San Antonio, New Braunfels, Seguin, 
Lockhart, La Grange, Pearsall, Pleasanton, Floresville, 
Karnes City, Gonzales, Cuero, and Hallettsville
253 PM CDT Tue May 18 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL THURSDAY 
AFTERNOON...

The Flash Flood Watch continues for

* A portion of south central Texas, including the following 
  areas, Atascosa, Bandera, Bastrop, Bexar, Blanco, Burnet, 
  Caldwell, Comal, De Witt, Fayette, Frio, Gillespie, Gonzales, 
  Guadalupe, Hays, Karnes, Kendall, Kerr, Lavaca, Lee, Llano, 
  Medina, Travis, Williamson, and Wilson. 

* Until Thursday afternoon

* Additional rainfall totals of 2 to 5 inches are expected with 
  isolated higher totals up to 8 inches possible. 

* The heavy rainfall could lead to flash flooding of low lying 
  buildings, creeks, streams, and roads. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$
040 
WGUS64 KEWX 190852
FFAEWX

Flood Watch
National Weather Service Austin/San Antonio TX
352 AM CDT Wed May 19 2021

.An upper level disturbance will combine with an unseasonably
moist airmass to generate multiple rounds of showers and
thunderstorms today through Thursday across South Central Texas.
Locally heavy rains can be expected and will lead to flash
flooding, especially in areas that have already received heavy
rain on Tuesday.

TXZ171>173-186>194-204>209-219>225-192000-
/O.CON.KEWX.FF.A.0002.000000T0000Z-210520T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Llano-Burnet-Williamson-Kerr-Bandera-Gillespie-Kendall-Blanco-
Hays-Travis-Bastrop-Lee-Medina-Bexar-Comal-Guadalupe-Caldwell-
Fayette-Frio-Atascosa-Wilson-Karnes-Gonzales-De Witt-Lavaca-
Including the cities of Llano, Burnet, Georgetown, Kerrville, 
Bandera, Fredericksburg, Boerne, Blanco, San Marcos, Austin, 
Bastrop, Giddings, Hondo, San Antonio, New Braunfels, Seguin, 
Lockhart, La Grange, Pearsall, Pleasanton, Floresville, 
Karnes City, Gonzales, Cuero, and Hallettsville
352 AM CDT Wed May 19 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY
AFTERNOON...

The Flash Flood Watch continues for

* A portion of south central Texas, including the following 
  areas, Atascosa, Bandera, Bastrop, Bexar, Blanco, Burnet, 
  Caldwell, Comal, De Witt, Fayette, Frio, Gillespie, Gonzales, 
  Guadalupe, Hays, Karnes, Kendall, Kerr, Lavaca, Lee, Llano, 
  Medina, Travis, Williamson, and Wilson. 

* Through Thursday afternoon

* Additional rainfall totals of 2 to 4 inches are expected with 
  isolated higher totals up to 6 inches possible. 

* The heavy rainfall could lead to flash flooding of low lying 
  buildings, creeks, streams, and roads. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.

&&

$$
671 
WGUS64 KEWX 191920
FFAEWX

Flood Watch
National Weather Service Austin/San Antonio TX
220 PM CDT Wed May 19 2021

TXZ171>173-186>193-204>208-219>221-192030-
/O.CAN.KEWX.FF.A.0002.000000T0000Z-210520T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Llano-Burnet-Williamson-Kerr-Bandera-Gillespie-Kendall-Blanco-Hays-
Travis-Bastrop-Medina-Bexar-Comal-Guadalupe-Caldwell-Frio-Atascosa-
Wilson-
Including the cities of Pearsall, Georgetown, Llano, Floresville, 
Boerne, Seguin, Burnet, Blanco, Fredericksburg, San Antonio, 
Pleasanton, Bandera, San Marcos, Bastrop, New Braunfels, Austin, 
Hondo, Lockhart, and Kerrville
220 PM CDT Wed May 19 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for a portion of south central Texas, 
including the following areas, Atascosa, Bandera, Bastrop, Bexar, 
Blanco, Burnet, Caldwell, Comal, Frio, Gillespie, Guadalupe, Hays, 
Kendall, Kerr, Llano, Medina, Travis, Williamson, and Wilson has 
been cancelled.

The Flood Watch is cancelled. Isolated heavy rain is possible and 
could cause minor flooding.

$$

TXZ194-209-222>225-200330-
/O.CON.KEWX.FF.A.0002.000000T0000Z-210520T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lee-Fayette-Karnes-Gonzales-De Witt-Lavaca-
Including the cities of La Grange, Karnes City, Giddings, Gonzales, 
Hallettsville, and Cuero
220 PM CDT Wed May 19 2021

...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THURSDAY AFTERNOON...

The Flash Flood Watch continues for

* A portion of south central Texas, including the following areas, 
  De Witt, Fayette, Gonzales, Karnes, Lavaca and Lee.

* Through Thursday afternoon.

* Locally heavy rainfall of 1 to 2 inches on top of saturated soil 
  will lead to flash flooding.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

You should monitor later forecasts and be prepared to take action 
should Flash Flood Warnings be issued.

&&

$$

BF
798 
WGUS64 KEWX 200222
FFAEWX

Flood Watch
National Weather Service Austin/San Antonio TX
922 PM CDT Wed May 19 2021

TXZ194-209-222>225-200330-
/O.CAN.KEWX.FF.A.0002.000000T0000Z-210520T1800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lee-Fayette-Karnes-Gonzales-De Witt-Lavaca-
Including the cities of Giddings, La Grange, Karnes City, 
Gonzales, Cuero, and Hallettsville
922 PM CDT Wed May 19 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for a portion of south central Texas has
been cancelled. Shower and thunderstorm activity have moved south
and east out of the area. Only low chances for residual rain 
across the eastern counties of the CWA, but otherwise, no 
significant rains are expected overnight or tomorrow morning. 

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 9:21 AM CDTRiver Flood WarningEWXFrio19 hr
May 17, 11:36 AM CDTSpecial Weather StatementEWXBurnet54 min
May 17, 11:58 AM CDTSpecial Weather StatementEWXBurnet47 min
May 17, 12:05 PM CDTSevere Thunderstorm WarningEWXBurnet, Llano55 min
May 17, 1:00 PM CDTSevere Thunderstorm WarningEWXBlanco, Burnet, Travis, Williamson60 min
May 17, 1:53 PM CDTSpecial Weather StatementEWXBastrop, Hays, Travis, Williamson52 min
May 17, 2:37 PM CDTSpecial Weather StatementEWXComal38 min
May 17, 3:16 PM CDTSpecial Weather StatementEWXFayette, Gonzales44 min
May 17, 3:25 PM CDTAreal Flood AdvisoryEWXFayette3 hr
May 17, 3:51 PM CDTSpecial Weather StatementEWXComal39 min
May 17, 3:59 PM CDTSpecial Weather StatementEWXGonzales, Lavaca61 min
May 17, 4:15 PM CDTAreal Flood AdvisoryEWXGonzales, Lavaca2 hr
May 17, 5:05 PM CDTSpecial Weather StatementEWXLavaca40 min
May 17, 6:08 PM CDTSpecial Weather StatementEWXVal Verde52 min
May 17, 6:11 PM CDTSpecial Weather StatementEWXDimmit49 min
May 17, 6:46 PM CDTSpecial Weather StatementEWXDimmit44 min
May 17, 6:48 PM CDTSevere Thunderstorm WarningEWXVal Verde41 min
May 17, 6:50 PM CDTSevere Thunderstorm WarningEWXDimmit25 min

Nearby

Flash Flood Watches in Texas, 2021Every flash flood watch 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.