Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 21, NWS Austin/San Antonio, TX

March 20, 20125 counties in Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Mar 20, 2012, 1:24 AM CDT for 5 counties in Texas. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Mar 20, 2012, 1:24 AM CDT (06:24 UTC)
Expired: Mar 20, 2012, 4:30 AM CDT
In force: 3 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Flood severity: None

Counties Atascosa County, TX, Bandera County, TX, Bexar County, TX, Frio County, TX, Medina County, TX

The radar

The Austin/San Antonio radar (KEWX), 55 km from the middle of the area, began a volume at 06:27 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.

What was reported inside it

Time	Report	Where	Remark
Mar 20, 2:12 AM CDT	FLASH FLOOD	San Antonio, TX	VANCE JACKSON AT SUNBURST...ORSINGER LANE AT SANDSTONE...AND SLEEPY HOLLOW AT SUNBURST AS WELL AS OTHER ROADS ARE CLOSED DUE TO FLOODING IN SAN ANTONIO.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 6.4 hours before the alert went out and 224 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2851 J/kg
Mixed-layer CIN: -113 J/kg
Mixed-layer LCL: 778 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 121 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 3.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

894 
WGUS54 KEWX 200624
FFWEWX
TXC013-019-029-163-325-200930-
/O.NEW.KEWX.FF.W.0021.120320T0624Z-120320T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
124 AM CDT TUE MAR 20 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHERN ATASCOSA COUNTY...
  SOUTHEASTERN BANDERA COUNTY...
  BEXAR COUNTY...
  NORTHEASTERN FRIO COUNTY...
  EASTERN MEDINA COUNTY...

* UNTIL 430 AM CDT.

* AT 122 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE  
  SAN ANTONIO TO NATALIA TO POTEET TO ELMENDORF AREA.  RAINFALL 
  AMOUNTS OF BETWEEN ONE AND TWO INCHES ARE EXPECTED IN LESS THAN 
  ONE HOUR ACROSS THE SAN ANTONIO METROPOLITAN AREA. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CASTROVILLE...DEVINE...HONDO...PLEASANTON...POTEET...SAN ANTONIO...
  UNIVERSAL CITY...ALAMO HEIGHTS...BADER...BANDERA FALLS...BIG
  FOOT...BIRY...CALAVERAS LAKE...CHINA GROVE...CLIFF...CROSS
  MOUNTAIN...DUNLAY...ELMENDORF...FAIR OAKS RANCH...HELOTES...HILL
  COUNTRY VILLA...HOLLYWOOD PARK...KIRBY...LACKLAND AFB...LACOSTE...
  LAKEHILLS...LEMING...LEON SPRINGS...LEON VALLEY AND LIVE OAK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IT IS HARD TO RECOGNIZE THE DANGERS OF FLOODING AT NIGHT. IF FLOOD
WATERS RISE ACT QUICKLY. DO NOT STAY IN FLOOD PRONE AREAS.

&&

LAT...LON 2898 9908 2948 9924 2978 9891 2972 9878
      2976 9855 2972 9844 2975 9842 2973 9836
      2967 9838 2956 9829 2955 9822 2949 9819
      2948 9812 2945 9812 2912 9840 2903 9834
      2894 9840

$$

1 follow-up statement

631 
WGUS74 KEWX 200751
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
251 AM CDT TUE MAR 20 2012

TXC013-019-029-163-325-200930-
/O.CON.KEWX.FF.W.0021.000000T0000Z-120320T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MEDINA TX-BEXAR TX-BANDERA TX-FRIO TX-ATASCOSA TX-
251 AM CDT TUE MAR 20 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 AM CDT FOR
NORTHERN ATASCOSA...NORTHEASTERN FRIO...SOUTHEASTERN BANDERA...BEXAR
AND EASTERN MEDINA COUNTIES...

AT 240 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT SHOWERS AND THUNDERSTORMS PRODUCING MODERATE TO HEAVY RAIN 
FROM POTEET TO THE SAN ANTONIO METROPOLITAN AREA.  

NUMEROUS ROAD CLOSURES HAVE BEEN REPORTED IN THE SAN ANTONIO AREA. 
 DREAMLAND DRIVE FROM VANCE JACKSON TO LOCKHILL
 VANCE JACKSON AT TREELINE
 VANCE JACKSON AT SUNBURST
 LESLIE ROAD AT LOOP 1604
 LESLIE ROAD AT BRAHN ROAD
 WHITE BONNET AT LOCKHILL
 WHITE BONNET AT HOLLYHOCK
 12000 OLD OCONNOR  
 ROLAND AVENUE SALADO CREEK
 GEORGE ROAD AT LOCKHILL SELMA 

LOCATIONS IN THE WARNING AREA INCLUDE BANDERA FALLS...CLIFF...MICO...
WINDCREST...UNIVERSAL CITY...TIMBERWOOD PARK...THE DOMINION...SHAVANO
PARK...LIVE OAK...LEON VALLEY...LEON SPRINGS...HOLLYWOOD PARK...HILL
COUNTRY VILLA...HELOTES...FAIR OAKS RANCH...CROSS MOUNTAIN...SELMA...
PIPE CREEK AND LAKEHILLS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IT IS HARD TO RECOGNIZE THE DANGERS OF FLOODING AT NIGHT. IF FLOOD
WATERS RISE ACT QUICKLY. DO NOT STAY IN FLOOD PRONE AREAS.

&&

LAT...LON 2898 9908 2948 9924 2978 9891 2972 9878
      2976 9855 2972 9844 2975 9842 2973 9836
      2967 9838 2956 9829 2955 9822 2949 9819
      2948 9812 2945 9812 2912 9840 2903 9834
      2894 9840

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 19, 7:17 PM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Frio	58 min
Mar 19, 7:29 PM CDT	Severe Thunderstorm Warning	EWX	Edwards, Kerr, Real	46 min
Mar 19, 7:35 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Kerr, Real	55 min
Mar 19, 7:37 PM CDT	Severe Thunderstorm Warning	EWX	Uvalde	53 min
Mar 19, 7:42 PM CDT	Severe Thunderstorm Warning	EWX	Gillespie	29 min
Mar 19, 7:44 PM CDT	Tornado Warning	EWX	Atascosa, Medina	31 min
Mar 19, 8:02 PM CDT	Tornado Warning	EWX	Bandera, Kerr	43 min
Mar 19, 8:02 PM CDT	Tornado Warning	EWX	Atascosa, Bexar, Medina	48 min
Mar 19, 8:07 PM CDT	Tornado Warning	EWX	Atascosa, Frio	53 min
Mar 19, 8:25 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Medina, Real, Uvalde	65 min
Mar 19, 8:29 PM CDT	Severe Thunderstorm Warning	EWX	Real, Uvalde	61 min
Mar 19, 8:39 PM CDT	Severe Thunderstorm Warning	EWX	Gillespie, Kendall, Kerr	66 min
Mar 19, 8:56 PM CDT	Tornado Warning	EWX	Atascosa, Bexar	22 min
Mar 19, 9:07 PM CDT	Severe Thunderstorm Warning	EWX	Kinney, Uvalde	53 min
Mar 19, 9:13 PM CDT	Areal Flood Warning	EWX	Bandera, Gillespie, Kerr, Real, Uvalde	10 min
Mar 19, 9:23 PM CDT	Flash Flood Warning	EWX	Bandera, Gillespie, Kerr, Real, Uvalde	3 hr
Mar 19, 9:30 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Kerr, Medina, Uvalde	60 min
Mar 19, 9:31 PM CDT	Severe Thunderstorm Warning	EWX	Kinney, Maverick, Real, Uvalde, Zavala	59 min
Mar 19, 9:59 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Gillespie, Kendall, Kerr	61 min
Mar 19, 10:31 PM CDT	Severe Thunderstorm Warning	EWX	Blanco, Gillespie	44 min
Mar 19, 10:34 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Kendall, Kerr	41 min
Mar 19, 10:58 PM CDT	Flash Flood Warning	EWX	Bandera, Kinney, Medina, Real, Uvalde	4 hr
Mar 19, 11:03 PM CDT	Flash Flood Warning	EWX	Bandera, Blanco, Burnet, Gillespie, Kendall, Kerr and 2 more	3 hr
Mar 19, 11:03 PM CDT	Severe Thunderstorm Warning	EWX	Medina, Uvalde	42 min
Mar 19, 11:16 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Gillespie, Kendall, Kerr, Medina	44 min
Mar 19, 11:39 PM CDT	Severe Thunderstorm Warning	EWX	Medina	21 min
Mar 20, 12:14 AM CDT	Areal Flood Advisory	EWX	Comal, Hays, Kendall, Travis, Williamson	3 hr
Mar 20, 12:20 AM CDT	Areal Flood Advisory	EWX	Atascosa, Bandera, Bexar, Medina	3 hr
Mar 20, 12:28 AM CDT	Areal Flood Advisory	EWX	Dimmit, Maverick, Uvalde, Zavala	3 hr
Mar 20, 1:03 AM CDT	Severe Thunderstorm Warning	EWX	Dimmit, Maverick	42 min
Mar 20, 1:11 AM CDT	River Flood Warning	EWX	Kerr	8 hr
Mar 20, 1:11 AM CDT	River Flood Warning	EWX	Kendall	8 hr
Mar 20, 1:41 AM CDT	Areal Flood Advisory	EWX	Bastrop, Bexar, Caldwell, Comal, Guadalupe, Hays and 4 more	109 min
Mar 20, 1:59 AM CDT	Flash Flood Warning	EWX	Bandera, Bastrop, Bexar, Blanco, Burnet, Caldwell and 7 more	3 hr
Mar 20, 2:16 AM CDT	Areal Flood Advisory	EWX	Atascosa, Frio, Guadalupe, Karnes, Medina, Wilson	104 min
Mar 20, 2:24 AM CDT	Flash Flood Warning	EWX	Bastrop, Caldwell, DeWitt, Fayette, Gonzales, Guadalupe and 3 more	3 hr
Mar 20, 3:09 AM CDT	Flash Flood Warning	EWX	Blanco, Burnet, Gillespie, Llano	3 hr
Mar 20, 3:51 AM CDT	Flash Flood Warning	EWX	DeWitt, Fayette, Gonzales, Karnes, Lavaca, Wilson	3 hr
Mar 20, 4:05 AM CDT	Tornado Warning	EWX	DeWitt, Karnes	25 min
Mar 20, 5:11 AM CDT	Flash Flood Warning	EWX	Bastrop, Blanco, Burnet, Caldwell, Comal, Guadalupe and 4 more	3 hr
Mar 20, 5:29 AM CDT	Flash Flood Warning	EWX	Bastrop, Caldwell, Fayette, Gonzales, Guadalupe, Lee	2 hr
Mar 20, 6:23 AM CDT	River Flood Warning	EWX	Bandera	4 hr
Mar 20, 7:27 AM CDT	River Flood Warning	EWX	Williamson	3 hr
Mar 20, 7:27 AM CDT	River Flood Warning	EWX	Williamson	13 hr
Mar 20, 8:29 AM CDT	River Flood Warning	EWX	Caldwell, Gonzales	11 hr
Mar 20, 8:29 AM CDT	River Flood Warning	EWX	Caldwell, Gonzales	11 hr
Mar 20, 8:29 AM CDT	River Flood Warning	EWX	Gonzales	36 hr
Mar 20, 8:29 AM CDT	River Flood Warning	EWX	DeWitt	36 hr
Mar 20, 10:32 AM CDT	Areal Flood Advisory	EWX	Bastrop	118 min

Nearby

Flash Flood Warnings in Texas, 2012 Every flash flood warning in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.