Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 56, NWS Austin/San Antonio, TX

August 19, 2012Bexar County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Aug 19, 2012, 2:00 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
Aug 19, 2012, 2:00 AM CDT (07:00 UTC)
Expired
Aug 19, 2012, 5:00 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), 54 km from the middle of the area, began a volume at 07:02 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
Aug 19, 2:17 AM CDTFLASH FLOOD2 Sse Lackland Afb, TXROAD CLOSURE. BROOKVALLEY AT RAY ELLISON BLVD
Aug 19, 2:18 AM CDTHEAVY RAIN 1.42 Sse Leon Valley, TX30 MIN RAINFALL
Aug 19, 2:52 AM CDTFLASH FLOOD4 N Lackland Afb, TXROAD CLOSURE. PINN RD FROM W. COMMERCE TO HWY151

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, 7.0 hours before the alert went out and 222 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 00:00Z on 2012-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1435 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 00:00Z on 2012-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 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
1435 J/kg
Mixed-layer CIN
-108 J/kg
Mixed-layer LCL
1442 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
51 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.7

Open this sounding in Storm Lab

The text

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

139 
WGUS54 KEWX 190700
FFWEWX
TXC029-191000-
/O.NEW.KEWX.FF.W.0056.120819T0700Z-120819T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
200 AM CDT SUN AUG 19 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

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

* UNTIL 500 AM CDT.

* AT 157 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS HAVE
  DETERMINED THAT RAINFALL ESTIMATES FROM DOPPLER RADAR INDICATE SLOW
  MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WESTERN   
  PART OF BEXAR COUNTY TO PUSH EASTWARD WITHIN THE NEXT FEW HOURS.   
  THESE STORMS ARE PRODUCING HEAVY RAINS WITH POSSIBLE ONE TO TWO    
  INCHES OF RAINFALL ACCUMULATIONS WITHIN AN HOUR. THE SAN ANTONIO   
  AREA WILL BEGIN TO FELL THE EFFECT OF THESE STORMS WITHIN THE NEXT 
  5 TO 15 MINUTES.

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


PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2929 9877 2970 9877 2970 9839 2954 9830
      2946 9815 2916 9840

$$
3 follow-up statements
806 
WGUS74 KEWX 190709
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
209 AM CDT SUN AUG 19 2012

TXC029-191000-
/O.CON.KEWX.FF.W.0056.000000T0000Z-120819T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-
209 AM CDT SUN AUG 19 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 AM CDT FOR BEXAR
COUNTY...

AT 206 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE 
WESTERN PART OF BEXAR COUNTY...PUSHING EASTWARD AT ABOUT 10 MPH.    
THESE STORMS ARE PRODUCING HEAVY RAINS WITH POSSIBLE ONE TO TWO      
INCHES OF RAINFALL ACCUMULATIONS WITHIN AN HOUR. THE SAN ANTONIO     
AREA WILL BEGIN TO FEEL THE EFFECT OF THESE STORMS WITHIN THE NEXT   
5 MINUTES.

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


PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2929 9877 2970 9877 2970 9840 2954 9830
      2946 9815 2916 9840

$$
786 
WGUS74 KEWX 190742
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
242 AM CDT SUN AUG 19 2012

TXC029-191000-
/O.CON.KEWX.FF.W.0056.000000T0000Z-120819T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-
242 AM CDT SUN AUG 19 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 AM CDT FOR BEXAR
COUNTY...

AT 235 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT A LINE OF STORMS MOVING EAST SOUTHEAST AT 10 MPH AND 
AFFECTING MOST AREAS ALONG HIGHWAY 281 FROM HOLLYWOOD PARK SOUTHWARD 
TO THELMA. THE STRONGEST STORMS AT THIS HOUR ARE OCCURRING JUST 
SOUTH OF THELMA AND MOVING INTO NORTHERN ATASCOSA COUNTY. EXPECT 
HEAVY RAINS AND THUNDERSTORM ACTIVITY ACROSS THE SAN ANTONIO AREA 
FOR THE NEXT FEW HOURS WITH POSSIBLE ONE TO TWO INCHES OF RAINFALL 
ACCUMULATIONS BEFORE THE STORMS MOVE AWAY OR DISSIPATE.

LOCATIONS IN THE WARNING AREA INCLUDE TERRELL HILLS...WINDCREST...THE
DOMINION...SHAVANO PARK...LIVE OAK...LEON VALLEY...LEON SPRINGS...
HOLLYWOOD PARK...HELOTES...CROSS MOUNTAIN AND ALAMO HEIGHTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 2929 9877 2970 9877 2970 9840 2954 9830
      2946 9815 2916 9840

$$
116 
WGUS74 KEWX 190845
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
345 AM CDT SUN AUG 19 2012

TXC029-191000-
/O.CON.KEWX.FF.W.0056.000000T0000Z-120819T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-
345 AM CDT SUN AUG 19 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 AM CDT FOR BEXAR
COUNTY...

AT 338 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT A LINE OF STORMS WITH VERY HEAVY RAINS AND THUNDERSTORMS 
AFFECTING THE SAN ANTONIO METRO AREA. SEVERAL ROADS HAVE BEEN CLOSED 
DUE TO THE HEAVY RAINS WITHIN THE PAST HOUR. EXPECT THESE STORMS TO 
SLOWLY MOVE EAST SOUTHEAST AT ABOUT 10 MPH WITH AN ADDITIONAL ONE TO 
TWO INCHES OF RAINFALL ACCUMULATIONS OVER PARTS OF SAN ANTONIO AND 
AREAS ALONG HIGHWAY 281 FROM THE CITY OF SAN ANTONIO SOUTH TO THE 
CITY OF THELMA.

LOCATIONS IN THE WARNING AREA INCLUDE WINDCREST...THE DOMINION...
TERRELL HILLS...SHAVANO PARK...LIVE OAK...LEON VALLEY...LEON
SPRINGS...HOLLYWOOD PARK...HELOTES...CROSS MOUNTAIN AND ALAMO
HEIGHTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 2929 9877 2970 9877 2970 9840 2954 9830
      2946 9815 2916 9840

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 9:18 PM CDTAreal Flood AdvisoryEWXGuadalupe2 hr
Aug 18, 10:01 PM CDTAreal Flood AdvisoryEWXWilliamson119 min
Aug 18, 10:14 PM CDTAreal Flood AdvisoryEWXBexar106 min
Aug 18, 10:28 PM CDTAreal Flood AdvisoryEWXTravis2 hr
Aug 18, 10:45 PM CDTFlash Flood WarningEWXTravis, Williamson105 min
Aug 18, 11:32 PM CDTFlash Flood WarningEWXBexar118 min
Aug 18, 11:40 PM CDTAreal Flood AdvisoryEWXBastrop, Lee110 min
Aug 18, 11:50 PM CDTAreal Flood AdvisoryEWXCaldwell, Gonzales, Guadalupe2 hr
Aug 19, 12:26 AM CDTAreal Flood AdvisoryEWXGillespie2 hr
Aug 19, 12:50 AM CDTAreal Flood AdvisoryEWXBandera, Frio, Medina, Uvalde, Zavala100 min
Aug 19, 1:16 AM CDTAreal Flood AdvisoryEWXFayette104 min
Aug 19, 1:30 AM CDTAreal Flood AdvisoryEWXBexar, Kendall2 hr
Aug 19, 2:56 AM CDTFlash Flood WarningEWXMedina3 hr
Aug 19, 4:00 AM CDTAreal Flood AdvisoryEWXAtascosa2 hr
Aug 19, 4:54 AM CDTAreal Flood AdvisoryEWXWilson2 hr
Aug 19, 5:12 AM CDTFlash Flood WarningEWXBexar3 hr
Aug 19, 5:40 AM CDTAreal Flood AdvisoryEWXZavala110 min
Aug 19, 8:33 AM CDTAreal Flood AdvisoryEWXBexar117 min
Aug 19, 10:25 AM CDTRiver Flood WarningEWXBexar69 min
Aug 19, 11:05 AM CDTRiver Flood WarningEWXBexar, Wilson22 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.