Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 15, NWS Austin/San Antonio, TX

February 17, 2012Bexar County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Feb 17, 2012, 10:52 PM CST for Bexar 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 17, 2012, 10:52 PM CST (04:52 UTC)
Expired
Feb 18, 2012, 3:00 AM CST
In force
4 hr
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), 47 km from the middle of the area, began a volume at 04:55 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, 1:48 AM CSTFLASH FLOOD2 N Terrell Hills, TXCAVE LANE AND KENILWORTH CLOSED DUE TO FLOODING.

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

The nearest sounding before it

Del Rio, TX (KDRT), launched 00:00Z, 4.9 hours before the alert went out and 233 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, Del Rio, 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.LCLEL10008507005003002001001 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, Del Rio, TX at 00:00Z on 2012-02-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 93 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
538 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
93 m²/s²
0-3 km storm-relative helicity
170 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

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

382 
WGUS54 KEWX 180452
FFWEWX
TXC029-180900-
/O.NEW.KEWX.FF.W.0015.120218T0452Z-120218T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1052 PM CST FRI FEB 17 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

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

* UNTIL 300 AM CST.

* AT 1049 PM CST...NATIONAL WEATHER SERVICE METEOROLOGISTS HAVE
  DETERMINED THAT RAINFALL ESTIMATES FROM DOPPLER RADAR INDICATE SLOW
  MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED    
  AREA. THREE QUARTERS TO ONE INCH OF RAIN HAS FALLEN ACROSS THE SAN 
  ANTONIO METRO AREA AND HEAVY SHOWERS ARE DEVELOPING OVER THE CITY  
  WHICH WILL BRING ONE TO TWO INCHES OF ADDITIONAL RAIN.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...SAN
  ANTONIO...ALAMO HEIGHTS...CHINA GROVE...CROSS MOUNTAIN...
  ELMENDORF...HELOTES...HILL COUNTRY VILLA...HOLLYWOOD PARK...
  KIRBY...LACKLAND AFB...LEON SPRINGS...LEON VALLEY...LIVE OAK...
  OLMOS PARK...SEA WORLD...SHAVANO PARK...ST. HEDWIG...TERRELL
  HILLS...THE DOMINION AND WINDCREST.

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 2945 9819 2916 9841 2928 9876 2968 9876
      2970 9843 2958 9834

$$
2 follow-up statements
632 
WGUS74 KEWX 180806
FFSEWX

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

TXC029-180900-
/O.CON.KEWX.FF.W.0015.000000T0000Z-120218T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-
206 AM CST SAT FEB 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 AM CST FOR BEXAR
COUNTY...

AT 200 AM CST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THAT MOST OF THE STORMS PRODUCING VERY HEAVY RAINFALL HAVE MOVED OUT 
OF THE SAN ANTONIO METRO AREA. EVEN THOUGH THE HEAVIEST RAINFALL HAS 
MOVED OUT OF THE SAN ANTONIO METRO AREA...ADDITIONAL LIGHT TO 
MODERATE SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO CONTINUE 
THROUGH THE EARLY MORNING HOURS. RADAR ESTIMATES THAT ONE TO ONE AND 
A HALF INCHES OF RAIN HAS FALLEN OVER PORTIONS OF SAN ANTONIO SINCE 
MIDNIGHT. ADDITIONAL RAINFALL OF ONE HALF OF AN INCH OR MORE WILL BE 
POSSIBLE THROUGH THE EARLY MORNING HOURS AND WILL LIKELY BE QUICK TO 
RUNOFF AND MAY CAUSE ADDITIONAL FLOODING.

LOCATIONS IN THE WARNING AREA INCLUDE WINDCREST...THE DOMINION...
TERRELL HILLS...SHAVANO PARK...LIVE OAK...LEON VALLEY...LEON
SPRINGS...HOLLYWOOD PARK...HILL COUNTRY VILLA...HELOTES...CROSS
MOUNTAIN AND ALAMO HEIGHTS.

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 2945 9819 2916 9841 2928 9876 2968 9876
      2970 9843 2958 9834

$$
790 
WGUS74 KEWX 180853
FFSEWX

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

TXC029-180901-
/O.EXP.KEWX.FF.W.0015.000000T0000Z-120218T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BEXAR TX-
253 AM CST SAT FEB 18 2012

...THE FLASH FLOOD WARNING FOR BEXAR COUNTY WILL BE ALLOWED TO  
EXPIRE AT 300 AM CST...

THE HEAVIEST RAINFALL HAS MOVED EAST OF BEXAR COUNTY AND THE SAN 
ANTONIO METRO AREA. SCATTERED SHOWERS ARE STILL POSSIBLE THROUGH THE 
EARLY MORNING HOURS...BUT ARE EXPECTED TO PRODUCE ONLY LIGHT RAIN. 

LAT...LON 2945 9819 2916 9841 2928 9876 2968 9876
      2970 9843 2958 9834

$$

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, 11:05 PM CSTFlash Flood WarningEWXBurnet, Llano3 hr
Feb 18, 12:41 AM CSTAreal Flood AdvisoryEWXBandera, Blanco, Gillespie, Kendall, Kerr109 min
Feb 18, 1:04 AM CSTFlash Flood WarningEWXTravis, Williamson4 hr
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.