Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 53, NWS Austin/San Antonio, TX

July 18, 2012Atascosa County, Bexar County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Jul 18, 2012, 3:32 PM CDT for Atascosa County, Bexar County, Texas. It was in force for 118 min. 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
Jul 18, 2012, 3:32 PM CDT (20:32 UTC)
Expired
Jul 18, 2012, 5:30 PM CDT
In force
118 min
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Flood severity
None

Counties Atascosa County, TX, Bexar County, TX

The radar

The Austin/San Antonio radar (KEWX), 66 km from the middle of the area, began a volume at 20:35 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 18, 4:30 PM CDTFLASH FLOODSan Antonio, TXLAW ENFORCMENT REPORTS FLASH FLOOD ON SOUTH FLORES STREET WITH HIGH WATER RESCUE IN PROGRESS

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, 8.5 hours before the alert went out and 217 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 2012-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3410 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 2012-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 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
3410 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
660 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
11 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.

009 
WGUS54 KEWX 182032
FFWEWX
TXC013-029-182230-
/O.NEW.KEWX.FF.W.0053.120718T2032Z-120718T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
332 PM CDT WED JUL 18 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

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

* UNTIL 530 PM CDT.

* AT 329 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS HAVE
  DETERMINED THAT RAINFALL ESTIMATES FROM DOPPLER RADAR INDICATE   
  THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WESTERN
  SECTIONS OF SAN ANTONIO FROM NEAR DOWNTOWN TO HELOTES WITH 
  ADDITIONAL THUNDERSTORMS TRAINING THUNDERSTORMS MOVING NORTHWARD
  INTO SOUTHERN BEXAR COUNTY.

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

1.20 INCHES OF RAIN WAS REPORTED 5 MILES WEST OF SAN ANTONIO IN LESS 
THAN ONE HOUR FROM THESE STORMS.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2920 9880 2963 9879 2969 9867 2967 9844
      2922 9832 2912 9840 2909 9839

$$
2 follow-up statements
958 
WGUS74 KEWX 182129
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
429 PM CDT WED JUL 18 2012

TXC013-029-182230-
/O.CON.KEWX.FF.W.0053.000000T0000Z-120718T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-ATASCOSA TX-
429 PM CDT WED JUL 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM CDT FOR
NORTHWESTERN ATASCOSA AND BEXAR COUNTIES...

AT 420 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO 
DETECT THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE SOUTHEAST 
PORTION OF BEXAR AND WESTERN ATASCOSA COUNTIES. THESE STORMS ARE 
MOVING NORTHWARD AT AROUND 20 MPH. HEAVY RAINS WILL BE IMPACTING 
HIGHWAY 37 NEARBY THELMA AND BROOKS CITY BASE WITHIN THE NEXT 10 
MINUTES WHILE AN ISOLATED HEAVY SHOWER WILL MOVE ACROSS THE 
INTERSECTION OF I-10 AND I-35 NEARBY KIRBY WITHIN THE NEXT SEVERAL 
MINUTES. ACROSS ATASCOSA COUNTY...HEAVY RAINFALL ARE OCCURRING EAST 
OF DAVIS AND MOVING TOWARD CHARLOTTE.

LOCATIONS IN THE WARNING AREA INCLUDE THE DOMINION...TERRELL HILLS...
SHAVANO PARK...SEA WORLD...SAN ANTONIO...OLMOS PARK...LEON VALLEY...
LEON SPRINGS...LACKLAND AFB...HOLLYWOOD PARK...HELOTES...CROSS
MOUNTAIN 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 2920 9880 2963 9879 2969 9867 2967 9844
      2922 9832 2912 9840 2909 9839

$$
006 
WGUS74 KEWX 182212
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
512 PM CDT WED JUL 18 2012

TXC013-029-182230-
/O.CON.KEWX.FF.W.0053.000000T0000Z-120718T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-ATASCOSA TX-
512 PM CDT WED JUL 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM CDT FOR
NORTHWESTERN ATASCOSA AND BEXAR COUNTIES...

AT 510 PM CDT...MOST OF THUNDERSTORM ACTIVITY HAS DIMINISHED ACROSS 
BEXAR COUNTY. HOWEVER...AN ISOLATED STORM WITH HEAVY RAIN IS 
AFFECTING THE HOLLYWOOD PARK AREA AND VICINITY. EARLIER VERY HEAVY 
RAINFALL HAS PRODUCED URBAN FLOODING ACROSS BEXAR 
COUNTY...ESPECIALLY ON SOUTH FLORES STREET...WHERE HIGH WATER RESCUE 
IS IN PROGRESS PER LAW ENFORCEMENT OFFICIALS REPORT. 

LOCATIONS IN THE WARNING AREA INCLUDE THE DOMINION...TERRELL HILLS...
SHAVANO PARK...SEA WORLD...SAN ANTONIO...OLMOS PARK...LEON VALLEY...
LEON SPRINGS...LACKLAND AFB...HOLLYWOOD PARK...HELOTES...CROSS
MOUNTAIN 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 2920 9880 2966 9874 2969 9868 2969 9861
      2966 9843 2930 9835 2926 9835 2912 9840
      2909 9839

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 3:06 PM CDTAreal Flood AdvisoryEWXBexar114 min
Jul 18, 5:40 PM CDTSevere Thunderstorm WarningEWXUvalde50 min
Jul 18, 6:45 PM CDTAreal Flood AdvisoryEWXZavala105 min
Jul 18, 6:52 PM CDTSevere Thunderstorm WarningEWXKinney, Maverick38 min

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.