Alert archive / Texas / Flash Flood Warnings in 2012

Flash Flood Warning 25, NWS Austin/San Antonio, TX

March 20, 20126 counties in Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Mar 20, 2012, 3:51 AM CDT for 6 counties in Texas. It was in force for 3 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: Mar 20, 2012, 3:51 AM CDT (08:51 UTC)
Expired: Mar 20, 2012, 7:00 AM CDT
In force: 3 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Flood severity: None

Counties DeWitt County, TX, Fayette County, TX, Gonzales County, TX, Karnes County, TX, Lavaca County, TX, Wilson County, TX

The radar

The Austin/San Antonio radar (KEWX), 96 km from the middle of the area, began a volume at 08:52 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

Time	Report	Where	Remark
Mar 20, 4:30 AM CDT	FLASH FLOOD	4 E Gonzales, TX	RAPID RISES OF WATER OVER ROADWAYS ON FM532 AND FM1680. DENTON CREEK SPILLING OVER.

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, 8.9 hours before the alert went out and 167 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2851 J/kg
Mixed-layer CIN: -113 J/kg
Mixed-layer LCL: 778 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 121 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 3.0

Open this sounding in Storm Lab

The text

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

433 
WGUS54 KEWX 200851
FFWEWX
TXC123-149-177-255-285-493-201200-
/O.NEW.KEWX.FF.W.0025.120320T0851Z-120320T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
351 AM CDT TUE MAR 20 2012

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  DEWITT COUNTY...
  FAYETTE COUNTY...
  GONZALES COUNTY...
  KARNES COUNTY...
  LAVACA COUNTY...
  SOUTHEASTERN WILSON COUNTY...

* UNTIL 700 AM CDT.

* AT 347 AM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS HAVE
  DETERMINED THAT RAINFALL ESTIMATES FROM DOPPLER RADAR INDICATE 
  SHOWERS AND THUNDERSTORMS WITH VERY HEAVY RAINFALL MOVING INTO
  THE COASTAL PLAINS FROM KENEDY TO CUERO TO HALLETTSVILLE.  

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  CUERO...FLATONIA...GONZALES...HALLETTSVILLE...KARNES CITY...
  KENEDY...KOSCIUSKO...LA GRANGE...MOULTON...SCHULENBURG...SHINER...
  YOAKUM...YORKTOWN...CESTOHOWA...CHEAPSIDE...EZZELL...FALLS CITY...
  FAYETTEVILLE...GILLETT...HOCHHEIM...MULDOON...NIXON...NORDHEIM...
  ROUND TOP...RUNGE...SMILEY...SPEAKS...SUBLIME...THOMASTON AND
  WAELDER.

EXPECT RAINFALL AMOUNTS NEAR 2 INCHES FROM THESE STORMS OVER THE 
NEXT SEVERAL HOURS CAUSING PONDING OF WATER OVER ROADS...ALONG WITH 
RISING WATER ACROSS LOW WATER CROSSINGS.   

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 2906 9693 2909 9699 2886 9730 2892 9742
      2866 9777 2871 9791 2869 9801 2890 9822
      3015 9677 3016 9666 2995 9657 2963 9686
      2933 9656

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 19, 7:17 PM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Frio	58 min
Mar 19, 7:29 PM CDT	Severe Thunderstorm Warning	EWX	Edwards, Kerr, Real	46 min
Mar 19, 7:35 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Kerr, Real	55 min
Mar 19, 7:37 PM CDT	Severe Thunderstorm Warning	EWX	Uvalde	53 min
Mar 19, 7:42 PM CDT	Severe Thunderstorm Warning	EWX	Gillespie	29 min
Mar 19, 7:44 PM CDT	Tornado Warning	EWX	Atascosa, Medina	31 min
Mar 19, 8:02 PM CDT	Tornado Warning	EWX	Bandera, Kerr	43 min
Mar 19, 8:02 PM CDT	Tornado Warning	EWX	Atascosa, Bexar, Medina	48 min
Mar 19, 8:07 PM CDT	Tornado Warning	EWX	Atascosa, Frio	53 min
Mar 19, 8:25 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Medina, Real, Uvalde	65 min
Mar 19, 8:29 PM CDT	Severe Thunderstorm Warning	EWX	Real, Uvalde	61 min
Mar 19, 8:39 PM CDT	Severe Thunderstorm Warning	EWX	Gillespie, Kendall, Kerr	66 min
Mar 19, 8:56 PM CDT	Tornado Warning	EWX	Atascosa, Bexar	22 min
Mar 19, 9:07 PM CDT	Severe Thunderstorm Warning	EWX	Kinney, Uvalde	53 min
Mar 19, 9:13 PM CDT	Areal Flood Warning	EWX	Bandera, Gillespie, Kerr, Real, Uvalde	10 min
Mar 19, 9:23 PM CDT	Flash Flood Warning	EWX	Bandera, Gillespie, Kerr, Real, Uvalde	3 hr
Mar 19, 9:30 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Kerr, Medina, Uvalde	60 min
Mar 19, 9:31 PM CDT	Severe Thunderstorm Warning	EWX	Kinney, Maverick, Real, Uvalde, Zavala	59 min
Mar 19, 9:59 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Gillespie, Kendall, Kerr	61 min
Mar 19, 10:31 PM CDT	Severe Thunderstorm Warning	EWX	Blanco, Gillespie	44 min
Mar 19, 10:34 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Kendall, Kerr	41 min
Mar 19, 10:58 PM CDT	Flash Flood Warning	EWX	Bandera, Kinney, Medina, Real, Uvalde	4 hr
Mar 19, 11:03 PM CDT	Flash Flood Warning	EWX	Bandera, Blanco, Burnet, Gillespie, Kendall, Kerr and 2 more	3 hr
Mar 19, 11:03 PM CDT	Severe Thunderstorm Warning	EWX	Medina, Uvalde	42 min
Mar 19, 11:16 PM CDT	Severe Thunderstorm Warning	EWX	Bandera, Gillespie, Kendall, Kerr, Medina	44 min
Mar 19, 11:39 PM CDT	Severe Thunderstorm Warning	EWX	Medina	21 min
Mar 20, 12:14 AM CDT	Areal Flood Advisory	EWX	Comal, Hays, Kendall, Travis, Williamson	3 hr
Mar 20, 12:20 AM CDT	Areal Flood Advisory	EWX	Atascosa, Bandera, Bexar, Medina	3 hr
Mar 20, 12:28 AM CDT	Areal Flood Advisory	EWX	Dimmit, Maverick, Uvalde, Zavala	3 hr
Mar 20, 1:03 AM CDT	Severe Thunderstorm Warning	EWX	Dimmit, Maverick	42 min
Mar 20, 1:11 AM CDT	River Flood Warning	EWX	Kerr	8 hr
Mar 20, 1:11 AM CDT	River Flood Warning	EWX	Kendall	8 hr
Mar 20, 1:24 AM CDT	Flash Flood Warning	EWX	Atascosa, Bandera, Bexar, Frio, Medina	3 hr
Mar 20, 1:41 AM CDT	Areal Flood Advisory	EWX	Bastrop, Bexar, Caldwell, Comal, Guadalupe, Hays and 4 more	109 min
Mar 20, 1:59 AM CDT	Flash Flood Warning	EWX	Bandera, Bastrop, Bexar, Blanco, Burnet, Caldwell and 7 more	3 hr
Mar 20, 2:16 AM CDT	Areal Flood Advisory	EWX	Atascosa, Frio, Guadalupe, Karnes, Medina, Wilson	104 min
Mar 20, 2:24 AM CDT	Flash Flood Warning	EWX	Bastrop, Caldwell, DeWitt, Fayette, Gonzales, Guadalupe and 3 more	3 hr
Mar 20, 3:09 AM CDT	Flash Flood Warning	EWX	Blanco, Burnet, Gillespie, Llano	3 hr
Mar 20, 4:05 AM CDT	Tornado Warning	EWX	DeWitt, Karnes	25 min
Mar 20, 5:11 AM CDT	Flash Flood Warning	EWX	Bastrop, Blanco, Burnet, Caldwell, Comal, Guadalupe and 4 more	3 hr
Mar 20, 5:29 AM CDT	Flash Flood Warning	EWX	Bastrop, Caldwell, Fayette, Gonzales, Guadalupe, Lee	2 hr
Mar 20, 6:23 AM CDT	River Flood Warning	EWX	Bandera	4 hr
Mar 20, 7:27 AM CDT	River Flood Warning	EWX	Williamson	3 hr
Mar 20, 7:27 AM CDT	River Flood Warning	EWX	Williamson	13 hr
Mar 20, 8:29 AM CDT	River Flood Warning	EWX	Caldwell, Gonzales	11 hr
Mar 20, 8:29 AM CDT	River Flood Warning	EWX	Caldwell, Gonzales	11 hr
Mar 20, 8:29 AM CDT	River Flood Warning	EWX	Gonzales	36 hr
Mar 20, 8:29 AM CDT	River Flood Warning	EWX	DeWitt	36 hr
Mar 20, 10:32 AM CDT	Areal Flood Advisory	EWX	Bastrop	118 min

Nearby

Flash Flood Warnings in Texas, 2012 Every 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.