Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 38, NWS Austin/San Antonio, TX

May 10, 20127 counties in Texas

NWS Austin/San Antonio, TX issued this flash flood warning at May 10, 2012, 10:42 PM CDT for 7 counties in Texas. It was in force for 4 hr. 2 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
May 10, 2012, 10:42 PM CDT (03:42 UTC)
Expired
May 11, 2012, 2:30 AM CDT
In force
4 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Flood severity
None

Counties Bastrop County, TX, Caldwell County, TX, Guadalupe County, TX, Hays County, TX, Lee County, TX, Travis County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 50 km from the middle of the area, began a volume at 03:44 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
May 10, 11:30 PM CDTFLASH FLOODN Austin, TXSEVERAL ROADS IN AUSTIN CLOSED DUE TO FLOODED ROADWAYS
May 10, 11:53 PM CDTFLASH FLOOD3 Ese Bastrop, TXWATER FLOODING A HOME ON PINE HILL LOOP.

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, 3.7 hours before the alert went out and 283 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 2012-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2214 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 2012-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 204 square meters per square second.19395878Sfc1 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
2214 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
636 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
204 m²/s²
0-3 km storm-relative helicity
274 m²/s²
Significant tornado parameter
3.4
Supercell composite
14.5

Open this sounding in Storm Lab

The text

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

840 
WGUS54 KEWX 110342
FFWEWX
TXC021-055-187-209-287-453-491-110730-
/O.NEW.KEWX.FF.W.0038.120511T0342Z-120511T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1042 PM CDT THU MAY 10 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  BASTROP COUNTY...
  CALDWELL COUNTY...
  NORTHERN GUADALUPE COUNTY...
  HAYS COUNTY...
  LEE COUNTY...
  TRAVIS COUNTY...
  WILLIAMSON COUNTY...

* UNTIL 230 AM CDT.

* AT 1042 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS HAVE      
  DETERMINED THAT FLASH FLOODING CONTINUES ALONG AND EAST OF THE 
  I-35 FROM NEW BRAUNFELS TO GEORGETOWN. HEAVY RAINS ONE TO 
  THREE INCHES ARE LIKELY AS A LINE OF STORMS MOVE EAST ACROSS
  GUADALUPE...CALDWELL...BASTROP...AND LEE COUNTIES. 

NUMEROUS REPORTS OF FLOODED LOW WATER CROSSINGS HAVE ALREADY BEEN 
REPORTED IN THE AUSTIN METRO AREA. THE EXPECTED ADDITIONAL RAINFALL 
AMOUNTS OF 1 TO 3 INCHES WILL LIKELY EXACERBATE THIS 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 2972 9760 2953 9777 2957 9811 2982 9798
      3004 9826 3091 9779 3088 9762 3076 9729
      3071 9725 3047 9715 3056 9697 3056 9693
      3047 9689 3033 9674 3031 9667

$$
1 follow-up statement
452 
WGUS74 KEWX 110448
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1148 PM CDT THU MAY 10 2012

TXC021-055-187-209-287-453-491-110730-
/O.CON.KEWX.FF.W.0038.000000T0000Z-120511T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
GUADALUPE TX-HAYS TX-LEE TX-TRAVIS TX-WILLIAMSON TX-CALDWELL TX-
BASTROP TX-
1148 PM CDT THU MAY 10 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM CDT FOR
BASTROP...CALDWELL...WILLIAMSON...TRAVIS...LEE...HAYS AND NORTHERN
GUADALUPE COUNTIES...

AT 1143 PM CDT...SEVERAL ROADS IN AUSTIN ARE CLOSED DUE TO FLOODED 
ROADWAYS. EVEN THOUGH...SHOWERS AND THUNDERSTORMS HAVE MOVED EAST 
AND OUT FROM MOST OF THE AFFECTED AREAS...FLOODING WILL CONTINUE AS 
FLOODED WATER SLOWLY RESIDE.

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.

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 2972 9760 2953 9777 2957 9811 2982 9798
      3004 9826 3091 9779 3088 9762 3076 9729
      3071 9725 3047 9715 3056 9697 3056 9693
      3047 9689 3033 9674 3031 9667

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 10, 7:21 PM CDTTornado WarningEWXDimmit, Frio, Zavala24 min
May 10, 7:59 PM CDTRiver Flood WarningEWXKerr18 hr
May 10, 8:02 PM CDTFlash Flood WarningEWXHays, Travis, Williamson118 min
May 10, 8:26 PM CDTSevere Thunderstorm WarningEWXTravis, Williamson49 min
May 10, 8:32 PM CDTRiver Flood WarningEWXVal Verde30 hr
May 10, 8:34 PM CDTAreal Flood AdvisoryEWXBexar116 min
May 10, 9:10 PM CDTFlash Flood WarningEWXBexar, Comal, Guadalupe, Hays3 hr
May 10, 9:59 PM CDTAreal Flood AdvisoryEWXBastrop, Caldwell, Comal, Guadalupe, Hays, Lee and 2 more2 hr
May 11, 12:06 AM CDTFlash Flood WarningEWXBexar, Comal3 hr
May 11, 2:37 AM CDTFlash Flood WarningEWXHays113 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.