Alert archive / Texas / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 62, NWS Austin/San Antonio, TX

May 12, 20114 counties in Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at May 12, 2011, 9:50 AM CDT for 4 counties in Texas. It was in force for 55 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: May 12, 2011, 9:50 AM CDT (14:50 UTC)
Expired: May 12, 2011, 10:45 AM CDT
In force: 55 min
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon

Counties Atascosa County, TX, Dimmit County, TX, Frio County, TX, Zavala County, TX

The radar

The Laughlin AFB radar (KDFX), 129 km from the middle of the area, began a volume at 14:51 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 12, 7:52 AM CDT	Severe Thunderstorm Watch	SPC	9 hr

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 12:00Z, 2.8 hours before the alert went out and 205 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: 2980 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 458 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 108 m²/s²
Significant tornado parameter: 2.9
Supercell composite: 13.7

Open this sounding in Storm Lab

The text

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

028 
WUUS54 KEWX 121450
SVREWX
TXC013-127-163-507-121545-
/O.NEW.KEWX.SV.W.0062.110512T1450Z-110512T1545Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
950 AM CDT THU MAY 12 2011

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN ATASCOSA COUNTY...
  NORTHEASTERN DIMMIT COUNTY...
  SOUTHERN FRIO COUNTY...
  SOUTHEASTERN ZAVALA COUNTY...

* UNTIL 1045 AM CDT.

* AT 940 AM CDT...NWS METEOROLOGISTS HAVE DETECTED A LINE OF SEVERE
  THUNDERSTORMS.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
  FROM PEARSALL TO BIG WELLS...AND MOVING EAST AT 25 MPH.

* SOME LOCATIONS IN THE WARNING INCLUDE LAS VEGAS...DERBY...DILLEY...
  GOLDFINCH...CHRISTINE...CHARLOTTE AND CAMPBELLTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 300 PM CDT
THURSDAY AFTERNOON FOR SOUTH CENTRAL TEXAS. A SEVERE THUNDERSTORM
WATCH ALSO REMAINS IN EFFECT UNTIL 300 PM CDT THURSDAY AFTERNOON FOR
SOUTH CENTRAL TEXAS.

&&

LAT...LON 2859 9967 2897 9912 2876 9825 2862 9863
      2863 9938 2836 9939
TIME...MOT...LOC 1450Z 270DEG 21KT 2892 9906 2855 9951

$$

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at May 12, 7:54 AM CDT, 1 hour 56 minutes earlier.

Area forecast discussion, May 12, 7:54 AM CDT, 1 hour 56 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
754 AM CDT THU MAY 12 2011

.UPDATE...
HAVE UPDATED TO ISSUE SEVERE THUNDERSTORM WATCH FURTHER EAST
TOWARD THE SAN ANTONIO METRO AREA SOUTHEAST TOWARD THE COASTAL
PLAINS. REMAINDER OF SOUTH CENTRAL TEXAS FORECAST IS ON TRACK.

&&

.PREV DISCUSSION... /ISSUED 649 AM CDT THU MAY 12 2011/

DISCUSSION...
SEE AVIATION SECTION BELOW FOR THE 12Z AVIATION FORECAST.

AVIATION...
MVFR CIGS WILL LIFT TO BECOME VFR AFTER 15Z THEN BACK TO MVFR AT
THE I-35 TERMINALS AFTER 04Z AND CONTINUE THROUGH AT LEAST 12Z.
MODERATE SE FLOW WILL PREVAIL TODAY THROUGH 00Z.

MAIN CONCERN TODAY WILL BE CONVECTION. CURRENTLY SEEING STRONG TO
SEVERE CONVECTION OVER THE RIO GRANDE PLAINS AND THIS WILL LIKELY
CONTINUE TO DEVELOP/SPREAD EAST DURING THE DAY. LARGE HAIL (ONE
INCH DIAMETER OR LARGER) AND CONVECTIVE WIND GUSTS OF 50 KTS OR
GREATER ARE POSSIBLE WITH CONVECTION. STORMS WILL ALSO PRODUCE
OUTFLOW BOUNDARIES PRODUCING WIND GUSTS OF 35 KTS OR GREATER. COLD
FRONT WILL BEGIN TO PUSH SOUTH THROUGH THE REGION AFTER 12Z
FRIDAY WITH CIGS LIFTING TO VFR AND NORTHERLY WINDS OF 10 TO 20 MPH.

PREV DISCUSSION... /ISSUED 336 AM CDT THU MAY 12 2011/

DISCUSSION...
CONVECTION RAPIDLY STARTING TO FIRE OUT WEST ALONG THE RIO GRANDE
AND OVER THE WESTERN EDWARDS PLATEAU. THIS CONVECTION IS DUE TO A
SURFACE BOUNDARY...APPROACHING UPPER LEVEL JET AND MINIMAL
CAPPING. WILL GO WITH CHANCE POPS DUE TO HIGH CAPES WILL MENTION
SEVERE. SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 10 AM (15Z).
WATCH WILL LIKELY BE EXTENDED EASTWARD OR OTHER WATCHES ISSUED
EAST IF THIS ONE LATER TODAY INTO TONIGHT AS THE SYSTEM PROGRESSES
EASTWARD. A COLD FRONT WILL MOVE ACROSS THE AREA EARLY FRIDAY
ENDING THE POPS. FOR THIS WEEKEND INTO EARLY NEXT WEEK...SURFACE
TO UPPER LEVEL RIDGES PERSISTS OVER THE AREA. HAVE GONE A LITTLE
WARMER THAN GUIDANCE HIGHS DUE TO SLIGHT DOWNSLOPE ALOFT. BY THE
MIDDLE OF NEXT WEEK ANOTHER UPPER LEVEL TROUGH MOVES INTO THE
WESTERN STATES WITH THE SURFACE HIGH MOVING OFF TO THE EAST
ALLOWING FOR A SOUTHERLY FLOW AND LOWER LEVEL MOISTURE TO RETURN
ALONG WITH WARMER NIGHTTIME TEMPERATURES. THE NEXT RAIN MAKING
SYSTEM IS LIKELY THE END OF NEXT WEEK.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              88  69  86  61  83 /  60  40  10   0   0
AUSTIN BERGSTROM INTL AIRPORT  89  69  86  56  82 /  60  40  10   0   0
NEW BRAUNFELS MUNI AIRPORT     90  68  89  59  83 /  60  30  -    0   0
BURNET MUNI AIRPORT            87  66  82  57  80 /  60  30  -    0   0
DEL RIO INTL AIRPORT           94  71  94  66  88 /  20  10  -    0   0
GEORGETOWN MUNI AIRPORT        87  68  83  57  80 /  60  40  10   0   0
HONDO MUNI AIRPORT             91  68  93  60  86 /  60  30  -    0   0
SAN MARCOS MUNI AIRPORT        89  70  87  59  82 /  60  40  10   0   0
LA GRANGE - FAYETTE REGIONAL   87  72  85  59  81 /  60  40  20   0   0
SAN ANTONIO INTL AIRPORT       89  70  89  62  84 /  60  30  -    0   0
STINSON MUNI AIRPORT           90  71  92  64  86 /  60  30  -    0   0

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

MESOSCALE/AVIATION...10
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...31

Hazardous weather outlook, May 12, 9:32 AM CDT, 18 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
932 AM CDT THU MAY 12 2011

TXZ171>173-183>194-202>209-217>225-228-131130-
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-
932 AM CDT THU MAY 12 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...TODAY AND TONIGHT...
A SEVERE THUNDERSTORM WATCH IS IN EFFECT THROUGH 3 PM FOR MUCH OF
SOUTH CENTRAL TEXAS AND THE HILL COUNTRY. THE MAIN THREATS WILL
BE LARGE HAIL AND DAMAGING WINDS...ALONG WITH THE POSSIBILITY OF
ISOLATED TORNADOES. SCATTERED TO NUMEROUS STRONG THUNDERSTORMS...
POSSIBLY SEVERE WILL CONTINUE INTO THE EVENING HOURS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY...
A COLD FRONT WILL MOVE SOUTH THROUGH THE REGION ON FRIDAY. THIS
WILL USER IN COOLER AND DRIER AIR WITH NO SIGNIFICANT WEATHER
EXPECTED.

.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL BE NEEDED THIS MORNING AND INTO THIS
EVENING.

In the hours before

Local storm report, May 12, 9:11 AM CDT, 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
911 AM CDT THU MAY 12 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0850 AM     HAIL             BOERNE                  29.80N  98.74W
05/12/2011  M0.50 INCH       KENDALL            TX   TRAINED SPOTTER

            PEA TO NEAR DINE SIZE.

&&

EVENT NUMBER EWX1100142

JPB

Local storm report, May 12, 9:13 AM CDT, 37 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
913 AM CDT THU MAY 12 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0900 AM     HAIL             BOERNE                  29.80N  98.74W
05/12/2011  M0.75 INCH       KENDALL            TX   TRAINED SPOTTER

&&

EVENT NUMBER EWX1100143

JPB

Local storm report, May 12, 9:18 AM CDT, 32 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
918 AM CDT THU MAY 12 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0918 AM     HAIL             CARRIZO SPRINGS         28.53N  99.86W
05/12/2011  E1.75 INCH       DIMMIT             TX   LAW ENFORCEMENT

&&

EVENT NUMBER EWX1100144

JPB

Local storm report, May 12, 9:27 AM CDT, 23 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
927 AM CDT THU MAY 12 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0915 AM     TSTM WND DMG     3 ESE HONDO             29.34N  99.12W
05/12/2011                   MEDINA             TX   PUBLIC

            DAMAGE TO SMALL PORTABLE BUILDING AND SMALL UTILITY
            POLE

&&

EVENT NUMBER EWX1100145

JPB

Local storm report, May 12, 9:30 AM CDT, 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
930 AM CDT THU MAY 12 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0925 AM     TSTM WND DMG     HONDO                   29.36N  99.16W
05/12/2011                   MEDINA             TX   EMERGENCY MNGR

            WINDS EST 60 PLUS MPH. LOTS OF TREE DAMAGE CITY WIDE.

0925 AM     HAIL             HONDO                   29.36N  99.16W
05/12/2011  M0.50 INCH       MEDINA             TX   EMERGENCY MNGR

            WINDS EST 60 PLUS MPH. LOTS OF TREE DAMAGE CITY WIDE.

&&

EVENT NUMBER EWX1100146
EVENT NUMBER EWX1100147

JPB

Local storm report, May 12, 9:46 AM CDT, 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
946 AM CDT THU MAY 12 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0945 AM     HAIL             HELOTES                 29.57N  98.69W
05/12/2011  M1.00 INCH       BEXAR              TX   BROADCAST MEDIA

&&

EVENT NUMBER EWX1100148

JPB

The office that day

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

Issued	Product	Office	Counties	Lasted
May 11, 7:09 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Llano	51 min
May 11, 7:12 PM CDT	Severe Thunderstorm Warning	EWX	Gillespie, Llano	63 min
May 11, 7:15 PM CDT	Areal Flood Advisory	EWX	Llano	105 min
May 11, 7:59 PM CDT	Severe Thunderstorm Warning	EWX	Gillespie, Llano	46 min
May 11, 8:37 PM CDT	Severe Thunderstorm Warning	EWX	Blanco, Burnet, Llano	23 min
May 11, 8:42 PM CDT	Areal Flood Advisory	EWX	Burnet	108 min
May 11, 8:56 PM CDT	Severe Thunderstorm Warning	EWX	Blanco, Burnet, Llano, Travis, Williamson	49 min
May 11, 9:33 PM CDT	Severe Thunderstorm Warning	EWX	Burnet, Williamson	27 min
May 11, 9:53 PM CDT	Severe Thunderstorm Warning	EWX	Williamson	37 min
May 11, 10:19 PM CDT	Severe Thunderstorm Warning	EWX	Hays, Travis	41 min
May 11, 10:49 PM CDT	Severe Thunderstorm Warning	EWX	Hays, Travis	41 min
May 12, 3:28 AM CDT	Severe Thunderstorm Warning	EWX	Val Verde	47 min
May 12, 4:20 AM CDT	Severe Thunderstorm Warning	EWX	Val Verde	40 min
May 12, 5:00 AM CDT	Areal Flood Advisory	EWX	Val Verde	2 hr
May 12, 5:05 AM CDT	Severe Thunderstorm Warning	EWX	Val Verde	40 min
May 12, 5:24 AM CDT	Flash Flood Warning	EWX	Val Verde	3 hr
May 12, 5:46 AM CDT	Severe Thunderstorm Warning	EWX	Edwards, Kinney, Val Verde	44 min
May 12, 6:30 AM CDT	Severe Thunderstorm Warning	EWX	Edwards, Kinney, Uvalde	60 min
May 12, 6:40 AM CDT	Tornado Warning	EWX	Kinney	35 min
May 12, 6:59 AM CDT	Severe Thunderstorm Warning	EWX	Bandera, Edwards, Kerr, Kinney, Maverick, Medina and 4 more	61 min
May 12, 7:06 AM CDT	Tornado Warning	EWX	Uvalde	39 min
May 12, 7:45 AM CDT	Tornado Warning	EWX	Uvalde	45 min
May 12, 8:05 AM CDT	Severe Thunderstorm Warning	EWX	Dimmit, Kinney, Maverick, Medina, Uvalde, Zavala	40 min
May 12, 8:26 AM CDT	Tornado Warning	EWX	Dimmit, Maverick, Zavala	49 min
May 12, 8:41 AM CDT	Severe Thunderstorm Warning	EWX	Bandera, Bexar, Comal, Dimmit, Frio, Kendall and 5 more	64 min
May 12, 8:49 AM CDT	River Flood Warning	EWX	Val Verde	11 hr
May 12, 8:53 AM CDT	Severe Thunderstorm Warning	EWX	Travis	37 min
May 12, 9:03 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Bexar, Medina	42 min
May 12, 9:07 AM CDT	Tornado Warning	EWX	Medina	23 min
May 12, 9:11 AM CDT	Severe Thunderstorm Warning	EWX	Blanco, Burnet, Comal, Gillespie, Hays, Kendall and 3 more	64 min
May 12, 9:20 AM CDT	Severe Thunderstorm Warning	EWX	Dimmit	40 min
May 12, 9:26 AM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Lee, Travis, Williamson	49 min
May 12, 9:36 AM CDT	Severe Thunderstorm Warning	EWX	Bexar, Comal, Guadalupe, Medina	54 min
May 12, 9:46 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Bexar, Blanco, Caldwell, Comal, Frio and 5 more	59 min
May 12, 9:48 AM CDT	Severe Thunderstorm Warning	EWX	Fayette, Lee	29 min
May 12, 10:02 AM CDT	Areal Flood Advisory	EWX	Atascosa, Bexar, Caldwell, Comal, Guadalupe, Hays and 4 more	118 min
May 12, 10:07 AM CDT	Severe Thunderstorm Warning	EWX	Dimmit	38 min
May 12, 10:15 AM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Caldwell, Hays, Lee, Travis, Williamson	45 min
May 12, 10:16 AM CDT	Flash Flood Warning	EWX	Bexar	104 min
May 12, 10:24 AM CDT	Flash Flood Warning	EWX	Caldwell, Hays, Travis, Williamson	3 hr
May 12, 10:37 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Bastrop, Caldwell, DeWitt, Fayette, Gonzales and 4 more	53 min
May 12, 10:58 AM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Caldwell, Fayette, Gonzales, Lavaca, Lee and 1 more	47 min
May 12, 11:28 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Bastrop, Caldwell, DeWitt, Fayette, Gonzales and 3 more	47 min
May 12, 11:32 AM CDT	Tornado Warning	EWX	Fayette, Gonzales, Lavaca	28 min

Nearby

Severe Thunderstorm Warnings in Texas, 2011 Every severe thunderstorm warning in 2011

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.