Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 45, NWS Austin/San Antonio, TX

July 11, 2012Bexar County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Jul 11, 2012, 8:16 AM CDT for Bexar County, 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
Jul 11, 2012, 8:16 AM CDT (13:16 UTC)
Expired
Jul 11, 2012, 11:00 AM CDT
In force
3 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Flood severity
None

County Bexar County, TX

The radar

The Austin/San Antonio radar (KEWX), 49 km from the middle of the area, began a volume at 13:18 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

TimeReportWhereRemark
Jul 11, 8:30 AM CDTHEAVY RAIN 1.741 N Castle Hills, TX1.52 INCHES IN 50 MINUTES.
Jul 11, 8:30 AM CDTHEAVY RAIN 2.242 Sse Leon Valley, TX2.24 INCHES IN ONE HOUR. WIND GUSTS TO 48 MPH.
Jul 11, 8:40 AM CDTFLASH FLOOD2 W Live Oak, TXSEVERAL ROADS ARE CLOSED IN AND AROUND SAN ANTONIO DUE TO FLOODING.

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, 1.3 hours before the alert went out and 220 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.

794 
WGUS54 KEWX 111316
FFWEWX
TXC029-111600-
/O.NEW.KEWX.FF.W.0045.120711T1316Z-120711T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BEXAR COUNTY...

* UNTIL 1100 AM CDT.

* AT 810 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS HAVE
  DETERMINED THAT SLOW MOVING THUNDERSTORMS WITH VERY HEAVY 
  RAINFALL WILL CAUSE RUNOFF AND FLASH FLOODING ACROSS THE SAN
  ANTONIO METRO AREA. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...SAN
  ANTONIO...ALAMO HEIGHTS...CALAVERAS LAKE...CHINA GROVE...
  ELMENDORF...HOLLYWOOD PARK...KIRBY...LACKLAND AFB...LEON VALLEY...
  LIVE OAK...OLMOS PARK...SEA WORLD...SHAVANO PARK...ST. HEDWIG...
  TERRELL HILLS AND WINDCREST.

THESE THUNDERSTORMS HAVE ALREADY PRODUCED HEAVY RAINFALL OF 2 TO 3 
INCHES ACROSS GUADALUPE AND COMAL COUNTIES SINCE 6 AM THIS MORNING. 
THE THUNDERSTORMS ARE EXPECTED TO PRODUCE AS MUCH AS 3 TO 4 INCHES 
OF RAIN ACROSS THE SAN ANTONIO METRO AREA...INCLUDING THE DOWNTOWN 
AREA. RAINFALL FROM THESE STORMS WILL BE QUICK TO RUNOFF AND WILL 
CAUSE FLASH FLOODING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2970 9858 2945 9814 2933 9823 2918 9841
      2936 9876

$$
3 follow-up statements
162 
WGUS74 KEWX 111345
FFSEWX

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

TXC029-111600-
/O.CON.KEWX.FF.W.0045.000000T0000Z-120711T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-
845 AM CDT WED JUL 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 AM CDT FOR
BEXAR COUNTY...

AT 845 AM CDT...THUNDERSTORMS PRODUCING VERY HEAVY RAIN CONTINUED 
OVER THE WARNED AREA.

THESE THUNDERSTORMS ARE PRODUCING VERY HEAVY RAINFALL. RADAR 
ESTIMATES HAVE INDICATED INTENSE RAINFALL RATES AS HIGH AS 6 INCHES 
OR MORE PER HOUR. THESE EXTREME RAINFALL RATES WILL RAPIDLY LEAD TO 
RUNOFF AND FLASH FLOODING. SUDDEN REDUCTIONS IN VISIBILITIES CAN 
ALSO BE EXPECTED WITH THESE INTENSE RAIN CORES. 

THE SAN ANTONIO INTERNATIONAL AIRPORT HAS ALREADY MEASURED OVER 2 
INCHES OF RAIN WITH THESE STORMS. ADDITIONAL OBSERVER REPORTS HAVE 
INDICATED THAT 2 TO 2.5 INCHES OF RAIN HAS FALLEN ACROSS THE SAN 
ANTONIO METRO AREA SINCE 8 AM. 

ADDITIONAL RAINFALL AMOUNTS OF 2 TO 3 INCHES OR MORE ARE POSSIBLE 
WITH THESE STORMS THIS MORNING. 

LOCATIONS IN THE WARNING AREA INCLUDE WINDCREST...TERRELL HILLS...ST.
HEDWIG...SHAVANO PARK...SEA WORLD...SAN ANTONIO...OLMOS PARK...LIVE
OAK...LEON VALLEY...KIRBY...HOLLYWOOD PARK AND ALAMO HEIGHTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

RUNOFF FROM HEAVY RAIN WILL FLOOD CREEKS, STREAMS, STREET
INTERSECTIONS, CULVERTS AND UNDERPASSES. LOW LYING PLACES THAT
NORMALLY FLOOD COULD BECOME DEATH TRAPS. DO NOT CROSS ANY FLOODED
AREA. TURN AROUND DON'T DROWN.

&&

LAT...LON 2970 9858 2945 9814 2933 9823 2918 9841
      2936 9876

$$
368 
WGUS74 KEWX 111455
FFSEWX

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

TXC029-111600-
/O.CON.KEWX.FF.W.0045.000000T0000Z-120711T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-
955 AM CDT WED JUL 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1100 AM CDT FOR
BEXAR COUNTY...

AT 9:45 AM CDT...LIGHT TO MODERATE RAIN WAS CONTINUING ACROSS THE 
SAN ANTONIO METRO AREA. WIDESPREAD HEAVY RAINFALL IS NOT EXPECTED 
ACROSS THE CITY THROUGH THE REST OF THIS MORNING...BUT LIGHT TO 
MODERATE RAIN IS EXPECTED TO CONTINUE THROUGH AT LEAST 10:30 AM. AN 
ADDITIONAL ONE HALF OF AN INCH TO NEAR ONE INCH OF RAIN IS POSSIBLE 
THROUGH THE REMAINDER OF THE MORNING. EVEN THOUGH HEAVY RAIN IS NO 
LONGER EXPECTED...RUNOFF FROM THE EARLIER INTENSE RAINFALL WILL 
CONTINUE TO CAUSE FLASH FLOODING ACROSS THE SAN ANTONIO METRO AREA 
THROUGH THIS MORNING. 

AT 9:45 AM...THE SAN ANTONIO INTERNATIONAL AIRPORT REPORTED 2.56 
INCHES OF RAIN. RAINFALL OBSERVERS ACROSS THE METRO AREA HAVE ALSO 
REPORTED RAINFALL TOTALS OF 2 TO 3 INCHES. AN ADDITIONAL HALF OF AN 
INCH TO NEAR ONE INCH OF RAIN IS POSSIBLE THIS MORNING. 

LOCATIONS IN THE WARNING AREA INCLUDE WINDCREST...TERRELL HILLS...ST.
HEDWIG...SHAVANO PARK...SEA WORLD...SAN ANTONIO...OLMOS PARK...LIVE
OAK...LEON VALLEY...KIRBY...HOLLYWOOD PARK AND ALAMO HEIGHTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

RUNOFF FROM HEAVY RAIN WILL FLOOD CREEKS, STREAMS, STREET
INTERSECTIONS, CULVERTS AND UNDERPASSES. LOW LYING PLACES THAT
NORMALLY FLOOD COULD BECOME DEATH TRAPS. DO NOT CROSS ANY FLOODED
AREA. TURN AROUND DON'T DROWN.

&&

LAT...LON 2970 9858 2945 9814 2933 9823 2918 9841
      2936 9876

$$
091 
WGUS74 KEWX 111552
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1052 AM CDT WED JUL 11 2012

TXC029-111600-
/O.CON.KEWX.FF.W.0045.000000T0000Z-120711T1600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-
1052 AM CDT WED JUL 11 2012

...THE FLASH FLOOD WARNING FOR BEXAR COUNTY WILL BE ALLOWED TO 
EXPIRE AT 1100 AM CDT...

AT 1045 AM CDT...ONLY LIGHT RAIN WAS FALLING ACROSS THE SAN ANTONIO 
METRO AREA. ADDITIONAL WIDESPREAD HEAVY RAINFALL IS NOT EXPECTED 
THROUGH THE EARLY AFTERNOON HOURS. HOWEVER...RUNOFF FROM THE HEAVY 
RAINFALL EARLIER THIS MORNING WILL CONTINUE. THERE IS A CONTINUING 
CHANCE FOR ADDITIONAL RAINFALL...POSSIBLY HEAVY AT TIMES...THROUGH 
THE AFTERNOON AND TONIGHT. ADDITIONAL FLASH FLOOD WARNINGS MAY BE 
NECESSARY.

LOCATIONS IN THE WARNING AREA INCLUDE WINDCREST...TERRELL HILLS...ST.
HEDWIG...SHAVANO PARK...SEA WORLD...SAN ANTONIO...OLMOS PARK...LIVE
OAK...LEON VALLEY...KIRBY...HOLLYWOOD PARK AND ALAMO HEIGHTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

RUNOFF FROM HEAVY RAIN WILL FLOOD CREEKS, STREAMS, STREET
INTERSECTIONS, CULVERTS AND UNDERPASSES. LOW LYING PLACES THAT
NORMALLY FLOOD COULD BECOME DEATH TRAPS. DO NOT CROSS ANY FLOODED
AREA. TURN AROUND DON'T DROWN.

&&

LAT...LON 2970 9858 2945 9814 2933 9823 2918 9841
      2936 9876

$$

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, 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
Jul 11, 4:38 PM CDTFlash Flood WarningEWXBexar, Comal, Guadalupe4 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.