Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 46, NWS Austin/San Antonio, TX

July 11, 2012Bexar County, Comal County, Guadalupe County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Jul 11, 2012, 4:38 PM CDT for Bexar County, Comal County, Guadalupe County, Texas. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 11, 2012, 4:38 PM CDT (21:38 UTC)
Expired
Jul 11, 2012, 8:30 PM CDT
In force
4 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Flood severity
None

Counties Bexar County, TX, Comal County, TX, Guadalupe County, TX

The radar

The Austin/San Antonio radar (KEWX), 15 km from the middle of the area, began a volume at 21:40 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, 9.6 hours before the alert went out and 219 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 2012-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2040 joules per kilogram.LCLLFCEL10008507005003002001001 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, Corpus Christi, TX at 12:00Z on 2012-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 square meters per square second.1939Sfc1 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
2040 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
702 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
58 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

162 
WGUS54 KEWX 112138
FFWEWX
TXC029-091-187-120130-
/O.NEW.KEWX.FF.W.0046.120711T2138Z-120712T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
438 PM CDT WED JUL 11 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL BEXAR COUNTY...
  SOUTHERN COMAL COUNTY...
  WESTERN GUADALUPE COUNTY...

* UNTIL 830 PM CDT.

* AT 437 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS HAVE
  DETERMINED THAT RAINFALL ESTIMATES FROM DOPPLER RADAR INDICATE SLOW
  MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED    
  AREA. DOPPLER RADAR ESTIMATES SUGGEST 2 TO 4 INCHES OF RAINFALL
  HAS OCCURRED SO FAR THIS AFTERNOON OVER THE I-35 CORRIDOR FROM 
  UNIVERSAL CITY TO NEW BRAUNFELS.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...NEW
  BRAUNFELS...SEGUIN...UNIVERSAL CITY...CIBOLO...GARDEN RIDGE...
  GERONIMO...LIVE OAK...MARION...MCQUEENEY...NEW BERLIN...SCHERTZ...
  SELMA...ST. HEDWIG...WINDCREST AND ZORN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2941 9813 2942 9813 2942 9816 2934 9822
      2958 9846 2982 9804 2980 9801 2976 9799
      2978 9798 2969 9785

$$
1 follow-up statement
658 
WGUS74 KEWX 112259
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
559 PM CDT WED JUL 11 2012

TXC029-091-187-120130-
/O.CON.KEWX.FF.W.0046.000000T0000Z-120712T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GUADALUPE TX-BEXAR TX-COMAL TX-
559 PM CDT WED JUL 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM CDT FOR
SOUTHERN COMAL...EAST CENTRAL BEXAR AND WESTERN GUADALUPE COUNTIES...

AT 546 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT AN AREA OF MODERATE TO HEAVY RAINS OVER THE WARNED AREA. 
AREAS EAST OF I-35 FROM UNIVERSAL CITY TO GERONIMO AND ZORN. AS OF 
521 PM CDT...2.42 INCHES WAS REPORTED AT THE NEW BRAUNFELS AIRPORT 
SINCE 1 PM...AND SOILS REMAIN SATURATED IN THIS AREA FROM RECENT 
RAINFALL. 

LOCATIONS IN THE WARNING AREA INCLUDE ZORN...GERONIMO...NEW BRAUNFELS
AND GARDEN RIDGE. LOW WATER CROSSINGS ARE LIKELY FLOODED OVER 
PORTIONS OF COMAL AND GUADALUPE COUNTY EAST OF I-35 AND NORTH OF 
HIGHWAY 78.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2941 9813 2942 9813 2942 9816 2934 9822
      2958 9846 2982 9804 2980 9801 2976 9799
      2978 9798 2969 9785

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 10, 7:02 PM CDTAreal Flood AdvisoryEWXEdwards, Kinney, Val Verde3 hr
Jul 10, 7:13 PM CDTAreal Flood AdvisoryEWXWilliamson107 min
Jul 10, 7:37 PM CDTFlash Flood WarningEWXEdwards, Kinney, Real, Uvalde4 hr
Jul 10, 8:50 PM CDTAreal Flood AdvisoryEWXTravis, Williamson2 hr
Jul 10, 9:29 PM CDTFlash Flood WarningEWXTravis3 hr
Jul 10, 9:36 PM CDTAreal Flood AdvisoryEWXBlanco, Hays3 hr
Jul 11, 2:00 AM CDTAreal Flood AdvisoryEWXGonzales, Guadalupe, Wilson3 hr
Jul 11, 6:05 AM CDTAreal Flood AdvisoryEWXDeWitt, Gonzales, Wilson3 hr
Jul 11, 6:59 AM CDTAreal Flood AdvisoryEWXBexar, Comal, Guadalupe, Wilson2 hr
Jul 11, 8:16 AM CDTFlash Flood WarningEWXBexar3 hr
Jul 11, 3:19 PM CDTAreal Flood AdvisoryEWXAtascosa, Bastrop, Bexar, Caldwell, Comal, Guadalupe and 4 more4 hr
Jul 11, 4:00 PM CDTAreal Flood AdvisoryEWXDimmit, Maverick, Zavala3 hr

Nearby

Flash Flood Warnings in Texas, 2012Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.