Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 51, NWS Austin/San Antonio, TX

July 15, 2012Williamson County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Jul 15, 2012, 7:29 PM CDT for Williamson County, Texas. It was in force for 2 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
Jul 15, 2012, 7:29 PM CDT (00:29 UTC)
Expired
Jul 15, 2012, 9:30 PM CDT
In force
2 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Emergency
Flash flood emergency
Flood severity
None

County Williamson County, TX

The radar

The Ft Hood radar (KGRK), 40 km from the middle of the area, began a volume at 00:29 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 15, 7:45 PM CDTFLASH FLOODRound Rock, TXEMERGENCY MANAGER REPORTED NUMEROUS ROADS CLOSED IN ROUND ROCK DUE TO FLOODING. HOME EVACUATIONS AND HIGH WATER RESCUES OCCURRING

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, 0.5 hours before the alert went out and 263 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 2012-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 526 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, Fort Worth, TX at 00:00Z on 2012-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -32 square meters per square second.193958Sfc1 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
526 J/kg
Mixed-layer CIN
-113 J/kg
Mixed-layer LCL
1333 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-32 m²/s²
0-3 km storm-relative helicity
-26 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.

715 
WGUS54 KEWX 160029
FFWEWX
TXC491-160230-
/O.NEW.KEWX.FF.W.0051.120716T0029Z-120716T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
729 PM CDT SUN JUL 15 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL WILLIAMSON COUNTY...

* UNTIL 930 PM CDT.

* AT 727 PM CDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED           
  FLASH FLOODING ACROSS THE WARNED AREA. DOPPLER RADAR ESTIMATES     
  THAT 3 TO 5 INCHES OF RAINFALL HAS OCCURRED AND AN ADDITIONAL 1 TO 
  2 INCHES ARE POSSIBLE. THE EMERGENCY MANAGER HAS REPORTED SEVERE   
  FLOODING IN SOUTHWEST WILLIAMSON COUNTY ALONG WITH EVACUATIONS IN  
  ROUND ROCK NEAR BRUSHY CREEK. 

  THIS IS A FLASH FLOOD EMERGENCY FOR ROUND ROCK NEAR BRUSHY CERRK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3054 9763 3048 9765 3048 9768 3046 9770
      3044 9776 3045 9780 3055 9775

$$
1 follow-up statement
118 
WGUS74 KEWX 160228
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
928 PM CDT SUN JUL 15 2012

TXC491-160235-
/O.EXP.KEWX.FF.W.0051.000000T0000Z-120716T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WILLIAMSON TX-
928 PM CDT SUN JUL 15 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 930 PM CDT FOR SOUTH
CENTRAL WILLIAMSON COUNTY...

THE FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE. FM 685 AT BRUSHY 
CREEK REMAINS CLOSED DUE TO HIGH WATER. LIGHT TO MODERATE SHOWERS ARE
STILL POSSIBLE FOR THE NEXT COUPLE OF HOURS BUT EXPECTED ADDITIONAL
RAINFALL AMOUNTS WILL NOT CAUSE ADDITIONAL FLOODING THIS EVENING.  

LAT...LON 3054 9763 3048 9765 3048 9768 3046 9770
      3044 9776 3045 9780 3055 9775

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 15, 7:39 PM CDTAreal Flood AdvisoryEWXHays111 min
Jul 15, 7:56 PM CDTAreal Flood AdvisoryEWXBastrop, Travis2 hr
Jul 15, 8:21 PM CDTFlash Flood WarningEWXTravis2 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.