Alert archive / Texas / Areal Flood Advisories in 2015

Areal Flood Advisory 252, NWS Austin/San Antonio, TX

August 20, 20154 counties in Texas

NWS Austin/San Antonio, TX issued this areal flood advisory at Aug 20, 2015, 12:26 PM CDT for 4 counties in Texas. It was in force for 2 hr.

The area

The counties it named.

The facts

Issued: Aug 20, 2015, 12:26 PM CDT (17:26 UTC)
Expired: Aug 20, 2015, 2:30 PM CDT
In force: 2 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon

Counties Atascosa County, TX, Bexar County, TX, Frio County, TX, Medina County, TX

The radar

The Austin/San Antonio radar (KEWX), 99 km from the middle of the area, began a volume at 17:27 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.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 5.4 hours before the alert went out and 213 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: 3717 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 733 m above ground
0-6 km bulk shear: 5 kt
0-1 km storm-relative helicity: -87 m²/s²
0-3 km storm-relative helicity: -82 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Austin/San Antonio, TX wrote its last area forecast discussion before this areal flood advisory went out at Aug 20, 12:00 PM CDT, 26 minutes earlier.

Area forecast discussion, Aug 20, 12:00 PM CDT, 26 minutes before

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Hazardous weather outlook, Aug 20, 3:26 AM CDT, 9 hours before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
326 AM CDT THU AUG 20 2015

TXZ171>173-183>194-202>209-217>225-228-211100-
LLANO-BURNET-WILLIAMSON-VAL VERDE-EDWARDS-REAL-KERR-BANDERA-
GILLESPIE-KENDALL-BLANCO-HAYS-TRAVIS-BASTROP-LEE-KINNEY-UVALDE-
MEDINA-BEXAR-COMAL-GUADALUPE-CALDWELL-FAYETTE-MAVERICK-ZAVALA-
FRIO-ATASCOSA-WILSON-KARNES-GONZALES-DE WITT-LAVACA-DIMMIT-
326 AM CDT THU AUG 20 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...TODAY AND TONIGHT.

ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE ACROSS MUCH
OF SOUTH CENTRAL TEXAS TODAY AND TONIGHT. THE MAIN THREAT
WILL BE SOME MODERATE TO LOCALLY HEAVY RAINS. HOWEVER...RUNOFF IS
EXPECTED TO BE SLOWER DUE TO DRY SOILS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

THUNDERSTORM CHANCES WILL CONTINUE ACROSS PORTIONS OF THE REGION
FRIDAY THROUGH TUESDAY...MAINLY ACROSS NORTHERN AND EASTERN AREAS.
LIGHTNING WILL BE THE MAIN HAZARD FROM THIS ACTIVITY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

In the hours before

Special weather statement, Aug 20, 10:20 AM CDT, 2 hours 6 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1020 AM CDT THU AUG 20 2015

TXZ209-225-201615-
FAYETTE TX-LAVACA TX-
1020 AM CDT THU AUG 20 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN FAYETTE AND
NORTHWESTERN LAVACA COUNTIES UNTIL 1115 AM CDT...

AT 1020 AM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
NEAR MOULTON...MOVING NORTH AT 15 MPH.

WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
SCHULENBURG...FLATONIA...MOULTON...HENKHAUS...FREYBURG...BRESLAU...
HIGH HILL...COLONY...MORAVIA...DUBINA...ENGLE...KOMENSKY...WITTING
AND FLOY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 2947 9698 2952 9719 2959 9719 2964 9713
      2968 9718 2982 9718 2976 9680
TIME...MOT...LOC 1520Z 200DEG 11KT 2956 9707

MSL

Special weather statement, Aug 20, 11:17 AM CDT, 1 hour 9 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1117 AM CDT THU AUG 20 2015

TXZ223-224-201700-
DE WITT TX-GONZALES TX-
1117 AM CDT THU AUG 20 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL GONZALES AND
CENTRAL DEWITT COUNTIES UNTIL NOON CDT...

AT 1116 AM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
NEAR CUERO...MOVING NORTH AT 20 MPH.

WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
CUERO...YOAKUM...CHEAPSIDE...WESTHOFF...ARNECKVILLE...SAMPLE...EDGAR
AND CONCRETE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 10 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 2898 9727 2898 9743 2929 9758 2929 9715
TIME...MOT...LOC 1616Z 197DEG 25KT 2916 9735

MSL

Special weather statement, Aug 20, 12:22 PM CDT, 4 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 19, 7:34 PM CDT	Severe Thunderstorm Warning	EWX	Edwards, Val Verde	56 min
Aug 19, 8:26 PM CDT	Special Weather Statement	EWX	Val Verde	64 min
Aug 20, 7:31 AM CDT	Areal Flood Advisory	EWX	Val Verde	3 hr
Aug 20, 8:02 AM CDT	Flash Flood Warning	EWX	Val Verde	3 hr
Aug 20, 10:20 AM CDT	Special Weather Statement	EWX	Fayette	55 min
Aug 20, 11:17 AM CDT	Special Weather Statement	EWX	DeWitt	43 min
Aug 20, 12:22 PM CDT	Special Weather Statement	EWX	Atascosa	23 min
Aug 20, 12:31 PM CDT	Special Weather Statement	EWX	Guadalupe	29 min
Aug 20, 12:46 PM CDT	Areal Flood Advisory	EWX	Bexar, Guadalupe, Wilson	119 min
Aug 20, 1:59 PM CDT	Special Weather Statement	EWX	Bandera	46 min
Aug 20, 2:22 PM CDT	Special Weather Statement	EWX	Bandera	23 min
Aug 20, 2:24 PM CDT	Areal Flood Advisory	EWX	Bandera, Medina, Uvalde	2 hr
Aug 20, 3:35 PM CDT	Special Weather Statement	EWX	Real	40 min
Aug 20, 3:41 PM CDT	Areal Flood Advisory	EWX	Real	109 min
Aug 20, 5:31 PM CDT	Special Weather Statement	EWX	Val Verde	44 min

Nearby

Areal Flood Advisories in Texas, 2015 Every areal flood advisory in 2015

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.