Alert archive / Texas / Flash Flood Warnings in 2011

Flash Flood Warning 3, NWS Austin/San Antonio, TX

May 12, 20114 counties in Texas

NWS Austin/San Antonio, TX issued this flash flood warning at May 12, 2011, 10:24 AM CDT for 4 counties in Texas. It was in force for 3 hr. 3 reports 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: May 12, 2011, 10:24 AM CDT (15:24 UTC)
Expired: May 12, 2011, 1:30 PM CDT
In force: 3 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Flood severity: None

Counties Caldwell County, TX, Hays County, TX, Travis County, TX, Williamson County, TX

The radar

The Austin/San Antonio radar (KEWX), 55 km from the middle of the area, began a volume at 15:27 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
May 12, 10:30 AM CDT	HEAVY RAIN 2	4 Nne Austin, TX	1.00 PAST 60 MIN. MINOR STREET FLOODING
May 12, 12:20 PM CDT	HEAVY RAIN 2.52	4 Nne Austin, TX	ST0RM TOTAL
May 12, 12:35 PM CDT	FLASH FLOOD	2 Nw Bergstrom, TX	8100 POSREN LN CLOSED BY WATER OVER ROAD

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 12:00Z, 3.4 hours before the alert went out and 269 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: 2980 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 458 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 2.9
Supercell composite: 13.7

Open this sounding in Storm Lab

The text

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

864 
WGUS54 KEWX 121524
FFWEWX
TXC055-209-453-491-121830-
/O.NEW.KEWX.FF.W.0003.110512T1524Z-110512T1830Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING FOR
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1024 AM CDT THU MAY 12 2011

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN CALDWELL COUNTY...
  EASTERN HAYS COUNTY...
  TRAVIS COUNTY...
  SOUTHERN WILLIAMSON COUNTY...

* UNTIL 130 PM CDT.

* AT 1023 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS HAVE
  DETERMINED THAT RAINFALL ESTIMATES FROM DOPPLER RADAR INDICATE 
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE AUSTIN TO 
  SAN MARCOS AREAS.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  ANDERSON MILL...AUSTIN...AUSTIN BERGSTROM INT AP...CEDAR PARK...
  GEORGETOWN...PFLUGERVILLE...ROUND ROCK...SAN MARCOS...SERENADA...
  TANGLEWOOD FOREST...TAYLOR...WINDEMERE...BEE CAVE...BUDA...
  COUPLAND...DRIFTWOOD...GEORGETOWN DAM...HUTTO...KYLE...LAKEWAY...
  LEANDER...LIBERTY HILL...MANOR...MANSFIELD DAM...MARTINDALE...
  MUSTANG RIDGE...NIEDERWALD...ONION CREEK...ROLLINGWOOD AND UHLAND.

RAINFALL AMOUNTS BETWEEN ONE AND TWO INCHES CAN BE EXPECTED IN LESS 
THAN ONE HOUR WHICH WILL CAUSE FLASH FLOODING ON LOW WATER CROSSINGS
ESPECIALLY IN METROPOLITAN AREAS.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN WATER COVERS THE ROAD...TURN AROUND DON'T DROWN. THE LIFE YOU
SAVE MAY BE YOUR OWN.

&&

LAT...LON 3058 9730 3025 9749 3016 9763 2978 9784
      2980 9786 2984 9786 2986 9790 2983 9794
      2994 9811 3079 9790

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
May 11, 7:09 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Llano	51 min
May 11, 7:12 PM CDT	Severe Thunderstorm Warning	EWX	Gillespie, Llano	63 min
May 11, 7:15 PM CDT	Areal Flood Advisory	EWX	Llano	105 min
May 11, 7:59 PM CDT	Severe Thunderstorm Warning	EWX	Gillespie, Llano	46 min
May 11, 8:37 PM CDT	Severe Thunderstorm Warning	EWX	Blanco, Burnet, Llano	23 min
May 11, 8:42 PM CDT	Areal Flood Advisory	EWX	Burnet	108 min
May 11, 8:56 PM CDT	Severe Thunderstorm Warning	EWX	Blanco, Burnet, Llano, Travis, Williamson	49 min
May 11, 9:33 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Williamson	27 min
May 11, 9:53 PM CDT	Severe Thunderstorm Warning	EWX	Williamson	37 min
May 11, 10:19 PM CDT	Severe Thunderstorm Warning	EWX	Hays, Travis	41 min
May 11, 10:49 PM CDT	Severe Thunderstorm Warning	EWX	Hays, Travis	41 min
May 12, 3:28 AM CDT	Severe Thunderstorm Warning	EWX	Val Verde	47 min
May 12, 4:20 AM CDT	Severe Thunderstorm Warning	EWX	Val Verde	40 min
May 12, 5:00 AM CDT	Areal Flood Advisory	EWX	Val Verde	2 hr
May 12, 5:05 AM CDT	Severe Thunderstorm Warning	EWX	Val Verde	40 min
May 12, 5:24 AM CDT	Flash Flood Warning	EWX	Val Verde	3 hr
May 12, 5:46 AM CDT	Severe Thunderstorm Warning	EWX	Edwards, Kinney, Val Verde	44 min
May 12, 6:30 AM CDT	Severe Thunderstorm Warning	EWX	Edwards, Kinney, Uvalde	60 min
May 12, 6:40 AM CDT	Tornado Warning	EWX	Kinney	35 min
May 12, 6:59 AM CDT	Severe Thunderstorm Warning	EWX	Bandera, Edwards, Kerr, Kinney, Maverick, Medina and 4 more	61 min
May 12, 7:06 AM CDT	Tornado Warning	EWX	Uvalde	39 min
May 12, 7:45 AM CDT	Tornado Warning	EWX	Uvalde	45 min
May 12, 8:05 AM CDT	Severe Thunderstorm Warning	EWX	Dimmit, Kinney, Maverick, Medina, Uvalde, Zavala	40 min
May 12, 8:26 AM CDT	Tornado Warning	EWX	Dimmit, Maverick, Zavala	49 min
May 12, 8:41 AM CDT	Severe Thunderstorm Warning	EWX	Bandera, Bexar, Comal, Dimmit, Frio, Kendall and 5 more	64 min
May 12, 8:49 AM CDT	River Flood Warning	EWX	Val Verde	11 hr
May 12, 8:53 AM CDT	Severe Thunderstorm Warning	EWX	Travis	37 min
May 12, 9:03 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Bexar, Medina	42 min
May 12, 9:07 AM CDT	Tornado Warning	EWX	Medina	23 min
May 12, 9:11 AM CDT	Severe Thunderstorm Warning	EWX	Blanco, Burnet, Comal, Gillespie, Hays, Kendall and 3 more	64 min
May 12, 9:20 AM CDT	Severe Thunderstorm Warning	EWX	Dimmit	40 min
May 12, 9:26 AM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Lee, Travis, Williamson	49 min
May 12, 9:36 AM CDT	Severe Thunderstorm Warning	EWX	Bexar, Comal, Guadalupe, Medina	54 min
May 12, 9:46 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Bexar, Blanco, Caldwell, Comal, Frio and 5 more	59 min
May 12, 9:48 AM CDT	Severe Thunderstorm Warning	EWX	Fayette, Lee	29 min
May 12, 9:50 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Dimmit, Frio, Zavala	55 min
May 12, 10:02 AM CDT	Areal Flood Advisory	EWX	Atascosa, Bexar, Caldwell, Comal, Guadalupe, Hays and 4 more	118 min
May 12, 10:07 AM CDT	Severe Thunderstorm Warning	EWX	Dimmit	38 min
May 12, 10:15 AM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Caldwell, Hays, Lee, Travis, Williamson	45 min
May 12, 10:16 AM CDT	Flash Flood Warning	EWX	Bexar	104 min
May 12, 10:37 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Bastrop, Caldwell, DeWitt, Fayette, Gonzales and 4 more	53 min
May 12, 10:58 AM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Caldwell, Fayette, Gonzales, Lavaca, Lee and 1 more	47 min
May 12, 11:28 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Bastrop, Caldwell, DeWitt, Fayette, Gonzales and 3 more	47 min
May 12, 11:32 AM CDT	Tornado Warning	EWX	Fayette, Gonzales, Lavaca	28 min

Nearby

Flash Flood Warnings in Texas, 2011 Every flash flood warning in 2011

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.