Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 54, NWS Austin/San Antonio, TX

August 18, 2012Travis County, Williamson County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Aug 18, 2012, 10:45 PM CDT for Travis County, Williamson County, Texas. It was in force for 105 min. 5 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 18, 2012, 10:45 PM CDT (03:45 UTC)
Expired
Aug 19, 2012, 12:30 AM CDT
In force
105 min
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Flood severity
None

Counties Travis County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 25 km from the middle of the area, began a volume at 03:47 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 18, 11:10 PM CDTFLOOD1 E Serenada, TXBERRY CREEK BRIEFLY TOUCHED FLOOD STAGE... RAAINFALL OVER 8 HR TIMESPAN
Aug 18, 11:10 PM CDTHEAVY RAIN 5.051 E Serenada, TXBERRY CREEK BRIEFLY TOUCHED FLOOD STAGE... RAAINFALL OVER 8 HR TIMESPAN
Aug 18, 11:25 PM CDTHEAVY RAIN 1.684 Sw Hutto, TX1 HR 35 MIN RAINFALL
Aug 18, 11:30 PM CDTFLASH FLOOD1 W Weir, TXROAD CLOSURE DUE TO HIGH WATER AT FM971 NEAR BERRY CREEK.
Aug 18, 11:59 PM CDTHEAVY RAIN 4.45 S Georgetown, TX24 HOUR RAINFALL TOTAL.

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, 3.8 hours before the alert went out and 314 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.

595 
WGUS54 KEWX 190345
FFWEWX
TXC453-491-190530-
/O.NEW.KEWX.FF.W.0054.120819T0345Z-120819T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1045 PM CDT SAT AUG 18 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN TRAVIS COUNTY...
  WILLIAMSON COUNTY...

* UNTIL 1230 AM CDT.

* AT 1040 PM CDT...THE PUBLIC REPORTED SLOW MOVING THUNDERSTORMS WITH
  VERY HEAVY RAINFALL ACROSS WILLIAMSON AND TRAVIS COUNTIES...
  GENERALLY ALONG AND EAST OF INTERSTATE 35.  RAINFALL AMOUNTS
  OF 1 TO 2 INCHES CAN BE EXPECTED IN A SHORT PERIOD OF TIME. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  AUSTIN...AUSTIN BERGSTROM INT AP...GEORGETOWN...GRANGER...
  PFLUGERVILLE...ROUND ROCK...SERENADA...TAYLOR...WINDEMERE...
  BARTLETT...COUPLAND...GEORGETOWN DAM...GRANGER DAM...HUTTO...
  JARRELL...MANOR...ONION CREEK...SUN CITY...THRALL AND WEIR.

OVER ONE INCH OF RAINFALL WAS REPORTED NEAR GEORGETOWN IN AROUND 10 
MINUTES.  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3088 9762 3075 9728 3071 9725 3049 9716
      3046 9737 3021 9752 3007 9772 3016 9781
      3042 9775 3067 9780 3089 9769

$$
1 follow-up statement
562 
WGUS74 KEWX 190419
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1119 PM CDT SAT AUG 18 2012

TXC453-491-190530-
/O.CON.KEWX.FF.W.0054.000000T0000Z-120819T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TRAVIS TX-WILLIAMSON TX-
1119 PM CDT SAT AUG 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 AM CDT FOR
WILLIAMSON AND EASTERN TRAVIS COUNTIES...

AT 1112 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONTINUED TO
DETECT THUNDERSTORMS PRODUCING VERY HEAVY RAIN.  THESE STORMS WERE
LOCATED ALONG A LINE EXTENDING FROM TAYLOR TO AUSTIN BERGSTROM INT
AP...MOVING SOUTHEAST AT 15 MPH.

OTHER LOCATIONS IN THE WARNING AREA INCLUDE GRANGER DAM...COUPLAND
AND THRALL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3088 9762 3075 9728 3071 9725 3049 9716
      3046 9737 3021 9752 3007 9772 3016 9781
      3042 9775 3067 9780 3089 9769

$$

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, 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, 2:00 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.