Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 55, NWS Austin/San Antonio, TX

August 18, 2012Bexar County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Aug 18, 2012, 11:32 PM CDT for 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
Aug 18, 2012, 11:32 PM CDT (04:32 UTC)
Expired
Aug 19, 2012, 1:30 AM CDT
In force
118 min
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), 44 km from the middle of the area, began a volume at 04:34 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, 1:00 AM CDTFLASH FLOOD5 W China Grove, TXROAD CLOSURE DUE TO FLOODING. AMITY RD AT ROLAND AVE.

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, 4.5 hours before the alert went out and 212 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.

736 
WGUS54 KEWX 190432
FFWEWX
TXC029-190630-
/O.NEW.KEWX.FF.W.0055.120819T0432Z-120819T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1132 PM CDT SAT AUG 18 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

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

* UNTIL 130 AM CDT.

* AT 1130 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS HAVE
  DETERMINED THAT RAINFALL ESTIMATES FROM DOPPLER RADAR INDICATE
  HEAVY RAINS OF 2 TO 3 INCHES ACROSS EAST CENTRAL BEXAR COUNTY NEAR 
  MARTINEZ AND KIRBY.  ADDITIONAL RAINFALL AMOUNTS NEAR ONE INCH
  ARE POSSIBLE.  

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...SAN
  ANTONIO...CHINA GROVE...KIRBY...OLMOS PARK...ST. HEDWIG AND TERRELL
  HILLS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2951 9822 2943 9817 2934 9824 2930 9852
      2936 9856 2948 9851

$$
1 follow-up statement
039 
WGUS74 KEWX 190604
FFSEWX

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

TXC029-190630-
/O.CON.KEWX.FF.W.0055.000000T0000Z-120819T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-
104 AM CDT SUN AUG 19 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 AM CDT FOR EAST
CENTRAL BEXAR COUNTY...

AT 1255 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
DETECT THUNDERSTORMS MOVING EASTWARD ACROSS THE WESTERN PART OF 
BEXAR COUNTY AND EXPECT MODERATE TO HEAVY SHOWERS TO AFFECT THE SAN 
ANTONIO AREA WITHIN THE NEXT 10 TO 20 MINUTES. ADDITIONAL RAINFALL 
OF ONE HALF INCH POSSIBLE WITH NEW STORMS.

LOCATIONS IN THE WARNING AREA INCLUDE TERRELL HILLS AND OLMOS PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 2951 9822 2943 9817 2934 9824 2930 9852
      2936 9856 2948 9851

$$

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, 11:40 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, 2:00 AM CDTFlash Flood WarningEWXBexar3 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.