Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 17, NWS Austin/San Antonio, TX

February 18, 2012Travis County, Williamson County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Feb 18, 2012, 1:04 AM CST for Travis County, Williamson County, Texas. It was in force for 4 hr. 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
Feb 18, 2012, 1:04 AM CST (07:04 UTC)
Expired
Feb 18, 2012, 5:00 AM CST
In force
4 hr
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), 32 km from the middle of the area, began a volume at 07:07 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
Feb 18, 3:15 AM CSTFLASH FLOODAustin, TXNUMEROUS ROAD CLOSURES DUE TO HIGH WATER. 5200 BLK OF JOE TANNER...5000 BLK OF WASSON RD... 6800 BLK OLD BEE CAVES RD... 10000 BLK DAVID MOORE DR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 7.1 hours before the alert went out and 249 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, Fort Worth, TX at 00:00Z on 2012-02-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Fort Worth, TX at 00:00Z on 2012-02-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 90 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1062 m above ground
0-6 km bulk shear
75 kt
0-1 km storm-relative helicity
90 m²/s²
0-3 km storm-relative helicity
130 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.

603 
WGUS54 KEWX 180704
FFWEWX
TXC453-491-181100-
/O.NEW.KEWX.FF.W.0017.120218T0704Z-120218T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
104 AM CST SAT FEB 18 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

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

* UNTIL 500 AM CST.

* AT 100 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  NUMEROUS SHOWERS AND THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS 
  THE WARNED AREA. 

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  ANDERSON MILL...AUSTIN...AUSTIN BERGSTROM INT AP...CEDAR PARK...
  GEORGETOWN...GRANGER...PFLUGERVILLE...ROUND ROCK...SERENADA...
  TANGLEWOOD FOREST...TAYLOR...WINDEMERE...ANDICE...BARTLETT...BEE
  CAVE...FLORENCE...GEORGETOWN DAM...GRANGER DAM...HUTTO...JARRELL...
  LAGO VISTA...LAKEWAY...LEANDER...LIBERTY HILL...MANOR...MANSFIELD
  DAM...MUSTANG RIDGE...ONION CREEK...ROLLINGWOOD AND SUN CITY.

THE SHOWERS AND THUNDERSTORMS WHICH WILL MOVE OVER THE AUSTIN METRO 
AREA ARE EXPECTED TO CONTINUE TO PRODUCE HEAVY RAIN WHICH WILL 
QUICKLY RUNOFF AND LEAD TO FLASH FLOODING.

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 3088 9762 3076 9730 3073 9726 3025 9749
      3004 9771 3036 9814 3056 9808 3077 9795
      3092 9781

$$
2 follow-up statements
823 
WGUS74 KEWX 180836
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
236 AM CST SAT FEB 18 2012

TXC453-491-181100-
/O.CON.KEWX.FF.W.0017.000000T0000Z-120218T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TRAVIS TX-WILLIAMSON TX-
236 AM CST SAT FEB 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 AM CST FOR
WILLIAMSON AND TRAVIS COUNTIES...

AT 230 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT THE HEAVIEST RAINFALL HAS MOVED OUT OF THE AUSTIN METRO AREA. 
HOWEVER...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED 
TO CONTINUE THROUGH THE EARLY MORNING HOURS AND MAY PRODUCE ANOTHER 
HALF OF AN INCH OR MORE OF RAINFALL. RAIN GAUGES HAVE VERIFIED THAT 
AS MUCH AS OVER ONE AND A HALF INCHES OF RAIN HAS FALLEN IN AND 
AROUND AUSTIN SINCE MIDNIGHT. SEVERAL AREA CREEKS AND STREAMS HAVE 
RAPIDLY RISEN TO NEAR OR ABOVE BANKFULL. ADDITIONAL RAINFALL...AS 
WELL AS RUNOFF...THROUGH THE NEXT FEW HOURS WILL CONTINUE TO CAUSE 
RAPID RISES AND POSSIBLE FLOODING OF CREEKS AND STREAMS AND ALSO 
SOME ROADS AND INTERSECTIONS. 

LOCATIONS IN THE WARNING AREA INCLUDE SUN CITY...LIBERTY HILL...
WEIR...SERENADA...JARRELL...GRANGER DAM...GRANGER...GEORGETOWN DAM...
GEORGETOWN...FLORENCE...BARTLETT AND ANDICE.

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.

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 3088 9762 3076 9730 3073 9726 3025 9749
      3004 9771 3036 9814 3056 9808 3077 9795
      3092 9781

$$
628 
WGUS74 KEWX 181055
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
455 AM CST SAT FEB 18 2012

TXC453-491-181100-
/O.EXP.KEWX.FF.W.0017.000000T0000Z-120218T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
TRAVIS TX-WILLIAMSON TX-
455 AM CST SAT FEB 18 2012

...THE FLASH FLOOD WARNING FOR WILLIAMSON AND TRAVIS COUNTIES WILL 
BE ALLOWED TO EXPIRE AT 500 AM CST ...

THE HEAVIEST RAINFALL HAS MOVED EAST OF THE AUSTIN METRO AREA. 
SCATTERED SHOWERS WILL BRING OCCASIONAL LIGHT TO MODERATE RAIN 
THROUGH THE EARLY AFTERNOON...BUT NEW RAINFALL TOTALS WILL GENERALLY 
AVERAGE ONE QUARTER OF AN INCH OR LESS. EVEN THOUGH HEAVY RAINFALL 
IS NO LONGER EXPECTED...RUNOFF FROM RAINFALL OVERNIGHT MAY CONTINUE 
TO CAUSE MINOR FLOODING OF CREEKS AND STREAMS IN AND AROUND THE 
AUSTIN METRO AREA THROUGH THE MORNING HOURS. 

LAT...LON 3088 9762 3076 9730 3073 9726 3025 9749
      3004 9771 3036 9814 3056 9808 3077 9795
      3092 9781

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 17, 10:42 PM CSTAreal Flood AdvisoryEWXMaverick108 min
Feb 17, 10:52 PM CSTFlash Flood WarningEWXBexar4 hr
Feb 17, 11:05 PM CSTFlash Flood WarningEWXBurnet, Llano3 hr
Feb 18, 12:41 AM CSTAreal Flood AdvisoryEWXBandera, Blanco, Gillespie, Kendall, Kerr109 min
Feb 18, 7:28 AM CSTAreal Flood AdvisoryEWXBexar2 hr
Feb 18, 8:34 AM CSTAreal Flood AdvisoryEWXBastrop, Caldwell, Comal, Hays, Travis116 min
Feb 18, 9:03 AM CSTAreal Flood AdvisoryEWXFayette117 min
Feb 18, 10:02 AM CSTAreal Flood AdvisoryEWXWilliamson118 min
Feb 18, 11:20 AM CSTAreal Flood AdvisoryEWXBastrop2 hr
Feb 18, 3:54 PM CSTAreal Flood AdvisoryEWXBastrop2 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.