Alert archive / Texas / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 34, NWS Austin/San Antonio, TX

April 18, 2015Blanco County, Hays County, Texas

NWS Austin/San Antonio, TX issued this severe thunderstorm warning at Apr 18, 2015, 8:18 PM CDT for Blanco County, Hays County, Texas. It was in force for 27 min. 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: Apr 18, 2015, 8:18 PM CDT (01:18 UTC)
Expired: Apr 18, 2015, 8:45 PM CDT
In force: 27 min
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Blanco County, TX, Hays County, TX

The radar

The Austin/San Antonio radar (KEWX), 72 km from the middle of the area, began a volume at 01:18 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
Apr 18, 8:25 PM CDT	HAIL 1	2 Ese Sandy, TX

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

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 7 minutes after it went out.

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
Apr 18, 2:13 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Del Rio, TX (KDLF), launched 00:00Z, 1.3 hours before the alert went out and 269 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: 667 J/kg
Mixed-layer CIN: -101 J/kg
Mixed-layer LCL: 2009 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: -17 m²/s²
0-3 km storm-relative helicity: 26 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

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

025 
WUUS54 KEWX 190118
SVREWX
TXC031-209-190145-
/O.NEW.KEWX.SV.W.0034.150419T0118Z-150419T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
818 PM CDT SAT APR 18 2015

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN HAYS COUNTY IN SOUTH CENTRAL TEXAS...
  BLANCO COUNTY IN SOUTH CENTRAL TEXAS...

* UNTIL 845 PM CDT

* AT 817 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR JOHNSON
  CITY...OR 11 MILES SOUTHWEST OF ROUND MOUNTAIN...MOVING EAST AT 45
  MPH.

  HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL. 

  SOURCE...RADAR INDICATED. 

  IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE 
           TO ROOFS...SIDING AND TREES. 

* LOCATIONS IMPACTED INCLUDE...
  ROUND MOUNTAIN...JOHNSON CITY...SANDY...CYPRESS MILL...ROCKY
  CREEK...PAYTON...HENLY AND PEDERNALES FALLS STATE PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

&&

LAT...LON 3038 9815 3036 9817 3029 9808 3000 9824
      3028 9859 3050 9855
TIME...MOT...LOC 0117Z 282DEG 40KT 3030 9845 

HAIL...1.00IN
WIND...60MPH
 
$$

LJH

1 follow-up statement

359 
WWUS54 KEWX 190130
SVSEWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
830 PM CDT SAT APR 18 2015

TXC031-209-190145-
/O.CON.KEWX.SV.W.0034.000000T0000Z-150419T0145Z/
HAYS TX-BLANCO TX-
830 PM CDT SAT APR 18 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR NORTHWESTERN HAYS AND BLANCO COUNTIES...

AT 827 PM CDT...A SEVERE THUNDERSTORM WAS LOCATED NEAR PEDERNALES
FALLS STATE PARK...OR 11 MILES SOUTH OF ROUND MOUNTAIN...MOVING EAST
AT 30 MPH.

HAZARD...60 MPH WIND GUSTS AND QUARTER SIZE HAIL. 

SOURCE...TRAINED WEATHER SPOTTERS REPORTED QUARTER SIZE 2 MILES 
EAST-SOUTHEAST OF SANDY. 

IMPACT...HAIL DAMAGE TO VEHICLES IS EXPECTED. EXPECT WIND DAMAGE TO 
         ROOFS...SIDING AND TREES. 

LOCATIONS IMPACTED INCLUDE...
ROUND MOUNTAIN...JOHNSON CITY...SANDY...CYPRESS MILL...ROCKY CREEK...
PAYTON...HENLY AND PEDERNALES FALLS STATE PARK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
BUILDING.

&&

LAT...LON 3038 9815 3036 9817 3029 9808 3000 9824
      3028 9859 3050 9855
TIME...MOT...LOC 0127Z 282DEG 40KT 3028 9832 

HAIL...1.00IN
WIND...60MPH
 
$$

LJH

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 Apr 18, 6:56 PM CDT, 1 hour 22 minutes earlier.

Area forecast discussion, Apr 18, 6:56 PM CDT, 1 hour 22 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
656 PM CDT SAT APR 18 2015

.AVIATION...
IN THE VERY SHORT TERM...A LINE OF STRONG TO SEVERE THUNDERSTORMS
WILL MOVE TO THE NORTH OF KAUS...WHILE AN ISOLATED CELL WILL MOVE
NORTH OF KSAT. VCTS WAS PLACED IN THE KAUS TAF...WHILE NO MENTION
WAS MADE FOR KSAT SINCE THAT STORM SHOULD STAY A BIT FURTHER AWAY.
AT THIS TIME...WE EXPECT BOTH SITES TO REMAIN FREE OF -SHRA/-TSRA...
BUT STORM MERGERS AND NEW DEVELOPMENT MAY REQUIRE UPDATES.

THE STORMS SHOULD DIE OFF/MOVE EAST AFTER 03Z...FOLLOWED BY MVFR
CIGS...THEN EVENTUALLY IFR CIGS AT THE I-35 SITES FROM 08-15Z.
KDRT WILL BE THE EXCEPTION WITH VFR CONDITIONS. A TROUGH WILL
SHIFT WINDS FROM S-SE TO SW AT 15Z SUNDAY...THEN A COLD FRONT
WILL MAKE A FURTHER SHIFT TO N AFTER 18Z AT KDRT AND AROUND 00Z
MONDAY AT THE I-35 SITES.

&&

.PREV DISCUSSION... /ISSUED 502 PM CDT SAT APR 18 2015/

UPDATE...
FORECAST PRODUCTS HAVE BEEN UPDATED TO REFLECT THE EASTWARD
EXTENSION OF WW# 72. NO OTHER CHANGES HAVE BEEN MADE TO THE
FORECAST AT THIS TIME.

PREV DISCUSSION... /ISSUED 257 PM CDT SAT APR 18 2015/

SHORT TERM (TONIGHT THROUGH SUNDAY NIGHT)...
UPPER AIR ANALYSIS THIS MORNING SHOWED A LOW OVER COLORADO WITH
SOUTHWESTERLY FLOW ACROSS TEXAS. AT THE SURFACE A DRYLINE WAS
STRETCHED FROM AROUND CHILDRESS TO SAN ANGELO TO THE BIG BEND. THE
PRESSURE FIELD ACROSS OUR CWA IS ILL DEFINED AND WINDS WERE
GENERALLY LIGHT AND VARIABLE. DEW POINT TEMPERATURES REMAIN HIGH
IN THE MID TO UPPER 60S. DRT SOUNDING THIS MORNING SHOWED A WEAK
CAP AT ABOUT 850MB. EXPECTING STORMS TO FORM ALONG THE DRYLINE AND
CONTINUE INTO THE FIRST PERIOD. MODELS FORECAST CAPE 1000-2000
J/KG WITH HIGHEST VALUES ALONG AND SOUTHEAST OF I-35 WITH VERTICAL
WIND SHEAR OF 30-40 KTS. SPC HAS US IN AN ENHANCED RISK FOR SEVERE
THUNDERSTORMS. LOOKS LIKE THE BEST SCENARIO FOR THIS EVENING WILL
BE A LINE OF STORMS MOVING THROUGH THE HILL COUNTRY TOWARD THE
SOUTHEAST AND ACROSS I-35 TOWARD I-10. THE MAIN THREAT WILL BE
LARGE HAIL AND DAMAGING WIND. THERE WILL ALSO BE A LOWER THREAT
FOR TORNADOES. STORMS SHOULD WEAKEN AFTER MIDNIGHT AND THEN MOVE
AWAY FROM OUR AREA. SUNDAY A WEAK COLD FRONT WILL MOVE THROUGH AND
TURN THE WINDS TO THE NORTH. THIS WILL BRING DRIER AIR AND END
RAIN CHANCES. THIS ALSO ALLOW TEMPERATURES TO CLIMB AND SUNDAY
WILL BE A VERY WARM DAY. THEN CLEAR SKIES WILL ALLOW FOR GOOD
RADIATIONAL COOLING SUNDAY NIGHT.

LONG TERM (MONDAY THROUGH SATURDAY)...
GRADUAL RIDGING WILL BUILD OVER THE SOUTHERN PLAINS INTO THE
MIDDLE OF THE NEW WEEK. THEN A TROUGH WILL DIG DOWN THROUGH THE
WEST AND THE RIDGE WILL BECOME MORE PRONOUNCED BY THURSDAY. THE
TROUGH WILL BEGIN TO PROGRESS EASTWARD FRIDAY AND MOVE TO THE
CENTRAL PLAINS BY SATURDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              61  88  56  74  55 /  40  -   -    0  20
AUSTIN BERGSTROM INTL AIRPORT  60  87  55  73  53 /  40  -   -    0  20
NEW BRAUNFELS MUNI AIRPORT     61  87  56  74  54 /  30   0  10  -   20
BURNET MUNI AIRPORT            59  86  52  73  53 /  40   0   0   0  20
DEL RIO INTL AIRPORT           60  89  58  77  60 /  20   0  -   10  20
GEORGETOWN MUNI AIRPORT        60  86  53  73  52 /  40  -   -    0  20
HONDO MUNI AIRPORT             61  88  57  75  55 /  20   0  -   -   30
SAN MARCOS MUNI AIRPORT        61  86  56  74  54 /  40   0  10  -   20
LA GRANGE - FAYETTE REGIONAL   62  86  57  74  57 /  40  10  10  -   20
SAN ANTONIO INTL AIRPORT       63  88  58  74  57 /  30   0  -   -   30
STINSON MUNI AIRPORT           62  88  59  74  57 /  20   0  10  -   30

&&

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

MESOSCALE/AVIATION...26
SYNOPTIC/GRIDS...24
PUBLIC SERVICE/DATA COLLECTION...33

Hazardous weather outlook, Apr 18, 2:34 PM CDT, 5 hours 44 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
234 PM CDT SAT APR 18 2015

TXZ171>173-183>194-202>209-217>225-228-191100-
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-
234 PM CDT SAT APR 18 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THERE IS CHANCE OF SEVERE THUNDERSTORMS FOR THIS AFTERNOON INTO
EVENING. THE MAIN THREAT WILL BE LARGE HAIL AND DAMAGING WIND
GUSTS. LOCALLY HEAVY RAIN IS ALSO POSSIBLE WHICH MAY CAUSE
ISOLATED FLOODING.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

NO HAZARDOUS WEATHER CONDITIONS ARE EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON INTO EVENING.

In the hours before

Local storm report, Apr 18, 7:23 PM CDT, 55 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
723 PM CDT SAT APR 18 2015

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

0710 PM     HAIL             1 SE LLANO              30.74N  98.66W
04/18/2015  M0.25 INCH       LLANO              TX   COCORAHS

&&

EVENT NUMBER EWX1500193

CVP

Special weather statement, Apr 18, 7:32 PM CDT, 46 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
732 PM CDT SAT APR 18 2015

TXZ171-172-190115-
BURNET TX-LLANO TX-
732 PM CDT SAT APR 18 2015

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN LLANO AND BURNET
COUNTIES UNTIL 815 PM CDT...

AT 732 PM CDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM NEAR WATSON TO NEAR INKS
LAKE STATE PARK TO ENCHANTED ROCK STATION...AND MOVING EAST AT 20
MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 30 MPH WILL BE POSSIBLE WITH
THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
KINGSLAND...MARBLE FALLS...BURNET...BERTRAM...BUCHANAN DAM...
GAINESVILLE...GRANITE SHOALS...HORSESHOE BAY...MEADOWLAKES...HIGHLAND
HAVEN...OXFORD...OATMEAL...SHADY GROVE...INKS LAKE STATE PARK...
SUNNYLANE...JOPPA...WATSON...LAKE VICTOR...COTTONWOOD SHORES AND
SUNRISE BEACH VILLAGE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT FOR
SOUTH CENTRAL TEXAS.

LAT...LON 3101 9794 3085 9795 3058 9819 3051 9847
      3052 9895 3073 9857 3101 9828
TIME...MOT...LOC 0032Z 294DEG 50KT 3096 9807 3070 9841 3051 9888

EMP

Special weather statement, Apr 18, 7:35 PM CDT, 43 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
735 PM CDT SAT APR 18 2015

TXZ188-190115-
GILLESPIE TX-
735 PM CDT SAT APR 18 2015

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL GILLESPIE COUNTY UNTIL
815 PM CDT...

AT 735 PM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
CHERRY SPRING...OR 12 MILES NORTHWEST OF FREDERICKSBURG...MOVING EAST
AT 35 MPH.

DIME SIZE HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
FREDERICKSBURG...DOSS...HARPER...CHERRY SPRING...ECKERT...WILLOW
CITY...TIVYDALE AND CRABAPPLE.

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 900 PM CDT FOR
SOUTH CENTRAL TEXAS.

LAT...LON 3028 9929 3049 9910 3049 9860 3015 9887
TIME...MOT...LOC 0035Z 280DEG 32KT 3041 9900

EMP

Local storm report, Apr 18, 7:49 PM CDT, 29 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
749 PM CDT SAT APR 18 2015

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

0405 PM     TSTM WND DMG     6 S FLORESVILLE         29.05N  98.16W
04/17/2015                   WILSON             TX   STORM CHASER

            DELAYED REPORT...TWO LARGE TREES BLOWN DOWN...POWER
            POLE BLOWN DOWN...AND TRAVEL TRAILER BLOWN OFF ROAD AND
            DESTROYED

&&

EVENT NUMBER EWX1500194

CVP

Local storm report, Apr 18, 7:54 PM CDT, 24 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
754 PM CDT SAT APR 18 2015

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

0753 PM     HAIL             3 NNW ECKERT            30.46N  98.76W
04/18/2015  M0.25 INCH       GILLESPIE          TX   TRAINED SPOTTER

&&

EVENT NUMBER EWX1500195

CVP

Local storm report, Apr 18, 8:11 PM CDT, 7 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
811 PM CDT SAT APR 18 2015

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

0739 PM     HAIL             1 NNW HILLTOP           30.41N  98.97W
04/18/2015  M0.75 INCH       GILLESPIE          TX   PUBLIC

&&

EVENT NUMBER EWX1500196

CVP

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 18, 7:01 PM CDT	Severe Thunderstorm Warning	EWX	Llano	29 min
Apr 18, 7:09 PM CDT	Special Weather Statement	EWX	Kendall	51 min
Apr 18, 7:32 PM CDT	Special Weather Statement	EWX	Burnet	43 min
Apr 18, 7:35 PM CDT	Special Weather Statement	EWX	Gillespie	40 min
Apr 18, 8:25 PM CDT	Special Weather Statement	EWX	Gillespie	50 min
Apr 18, 8:44 PM CDT	Severe Thunderstorm Warning	EWX	Blanco, Burnet, Hays, Travis	31 min
Apr 18, 9:13 PM CDT	Severe Thunderstorm Warning	EWX	Travis	32 min
Apr 18, 9:20 PM CDT	Special Weather Statement	EWX	Gillespie	40 min
Apr 18, 9:35 PM CDT	Areal Flood Advisory	EWX	Gillespie, Kendall, Kerr	3 hr
Apr 18, 9:44 PM CDT	Special Weather Statement	EWX	Bastrop, Caldwell, Lee	46 min
Apr 18, 11:25 PM CDT	Special Weather Statement	EWX	Kendall	35 min
Apr 19, 9:59 AM CDT	River Flood Warning	EWX	DeWitt	36 hr
Apr 19, 2:50 PM CDT	Special Weather Statement	EWX	Lee	25 min
Apr 19, 2:55 PM CDT	Severe Thunderstorm Warning	EWX	Lee	35 min
Apr 19, 3:24 PM CDT	Special Weather Statement	EWX	Caldwell	51 min
Apr 19, 3:39 PM CDT	Special Weather Statement	EWX	Bastrop	36 min
Apr 19, 3:53 PM CDT	Severe Thunderstorm Warning	EWX	Bastrop	37 min
Apr 19, 4:18 PM CDT	Severe Thunderstorm Warning	EWX	Fayette	27 min
Apr 19, 4:31 PM CDT	Special Weather Statement	EWX	Lee	14 min
Apr 19, 4:43 PM CDT	Severe Thunderstorm Warning	EWX	Fayette	32 min
Apr 19, 4:49 PM CDT	Special Weather Statement	EWX	Lee	41 min
Apr 19, 5:13 PM CDT	Severe Thunderstorm Warning	EWX	Fayette	47 min
Apr 19, 5:50 PM CDT	Severe Thunderstorm Warning	EWX	Fayette	40 min
Apr 19, 6:49 PM CDT	Special Weather Statement	EWX	Fayette	41 min

Nearby

Severe Thunderstorm Warnings in Texas, 2015 Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.