Special Weather Statement, NWS Austin/San Antonio, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1231 PM CDT SUN AUG 17 2014

.UPDATE...UPDATE FOR 18Z AVIATION BELOW.

&&

.AVIATION...MID LEVEL SHEAR/VORTICITY AXIS ROUGHLY NEAR A KCOM-
KOZA LINE...THEN SSW INTO MEXICO. FOCUS FOR SCT SHRAS AND TSTMS
SHOULD BE ACROSS THE WESTERN CWA DURING THE AFTERNOON HOURS CLOSER
TO THIS FEATURE. HAVE INCLUDED TEMPO TSRA IN DRT TAF THROUGH 21Z.
A FEW STORMS COLD PRODUCE GUSTY AND ERRATIC OUTFLOW WINDS. A
COUPLE OF HI RES MODELS SUGGEST DEVELOPMENT FARTHER EAST INTO THE
HILL COUNTRY...POSSIBLY NEAR THE KAUS AREA LATE AFTERNOON AND
EVENING. HOWEVER CONFIDENCE IS CURRENTLY LOWER IN THIS HAPPENING
AND PREFER TO SEE TRENDS DURING THE MID AND LATE AFTERNOON BEFORE
INCLUDING MENTION IN KAUS TAF. OUTSIDE OF ANY SHRAS/TSRAS...VFR
CONDITIONS ACROSS TAF SITES THROUGH THE AFTERNOON AND EVENING.
MVFR STRATUS DEVELOPING 08Z-12Z ACROSS I-35 CORRIDOR MON
MORNING...POSSIBLY OUT NEAR DRT AFTER 12Z.

&&

.PREV DISCUSSION... /ISSUED 1040 AM CDT SUN AUG 17 2014/

UPDATE...
MORNING FORECAST ADJUSTED SLIGHTLY FOR CLOUDS AND TEMPERATURE
TRENDS BASED ON THE CONVECTION OVER THE HILL COUNTRY AND CENTRAL
TX. A WEAK MCS SHOULD LEAVE PLENTY OF REMNANT CLOUDS OVER NORTHERN
COUNTIES THROUGH THE DAY AND RESULT IN A TEMPERATURE OFFSET OF
ABOUT 2-4 DEGREES. SUBSIDENCE SOUTH AND EAST OF THE COMPLEX SHOULD
CONTINUE TO PROMOTE MOSTLY SUNNY SKIES AND HIGH HEAT INDICES OF
103-107 DEGREES.

PREV DISCUSSION... /ISSUED 633 AM CDT SUN AUG 17 2014/

AVIATION...
/12Z TAFS/
MVFR CONDITIONS ARE EXPECTED THROUGH 14Z ACROSS THE I-35 SITES
WITH CIGS BECOMING VFR FOR THE REST OF TODAY. A CLUSTER OF STORMS
ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE OVER CENTRAL TEXAS IS
EXPECTED TO PUSH TO THE SOUTH AND AFFECT THE RIO GRANDE PLAINS AND
NORTHERN HILL COUNTRY THIS MORNING THROUGH THE EVENING HOURS. WINDS
WILL BE MAINLY FROM THE SOUTH 10 TO 13 KNOTS. MVFR CIGS RETURN
AROUND 07Z/08Z MONDAY ALONG THE I-35 TERMINALS.

PREV DISCUSSION... /ISSUED 353 AM CDT SUN AUG 17 2014/

SHORT TERM (TODAY THROUGH MONDAY)...
EARLY MORNING RADAR DATA SHOWS CONVECTION ONGOING ACROSS THE
SOUTHERN EDWARDS PLATEAU. THIS ACTIVITY IS DEVELOPING IN PROXIMITY
TO A WEAK UPPER TROUGH/SHEAR AXIS ALONG WITH A NARROW BAND OF
HIGHER MOISTURE (PWAT ROUGHLY 2"). THE UPPER TROUGH/SHEAR AXIS
WILL MIGRATE SOUTHWARD TODAY. THE EXPECTED LOCATION OF THIS
FEATURE ALONG WITH DAYTIME HEATING WILL PLACE THE SOUTHERN
EDWARDS PLATEAU AND WESTERN HILL COUNTRY IN THE FAVORED AREA FOR
RAINFALL TODAY. BASED ON CURRENT TRENDS AND HI-RES MODEL DATA...
WE HAVE INCREASED RAIN CHANCES ACROSS THE ABOVE MENTIONED AREAS.
GIVEN THE WEAK FLOW ALOFT AND AVAILABLE MOISTURE...A FEW LOCATIONS
GENERALLY NORTH OF A ROCKSPRINGS TO FREDERICKSBURG TO LLANO LINE
COULD SEE UP TO 2" OF RAIN. AGAIN...THESE RAINFALL AMOUNTS WILL
LIKELY REMAIN VERY LOCALIZED. ELSEWHERE... CAN/T RULE OUT MAINLY
ISOLATED SHOWERS AND THUNDERSTORMS ACROSS MOST OF SOUTH CENTRAL
TEXAS TODAY. ON MONDAY...THE UPPER TROUGH/SHEAR AXIS WEAKENS. WE/LL
MENTION A SLIGHT CHANCE FOR CONVECTION ACROSS VAL VERDE COUNTY AND
NEAR THE COASTAL PLAINS TO ACCOUNT FOR THE SEA BREEZE.

LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...
MID AND UPPER LEVEL RIDGING WILL BUILD ACROSS TEXAS THROUGH THE
WORK WEEK. THIS WILL KEEP MOST AREAS DRY...EXCEPT FOR POSSIBLY THE
COASTAL PLAINS. THIS AREA WILL LIKELY SEE AT LEAST ISOLATED
AFTERNOON SHOWERS AND THUNDERSTORMS DUE TO DAYTIME HEATING AND THE
SEA BREEZE. TEMPERATURES WILL CONTINUE TO REMAIN ABOVE NORMAL WITH
HIGHS IN THE MID 90S TO NEAR 100 AND LOWS GENERALLY IN THE 70S.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              76  99  76  99  76 /  20  -   10  10  10
AUSTIN BERGSTROM INTL AIRPORT  75  99  74  99  74 /  20  -   10  10  10
NEW BRAUNFELS MUNI AIRPORT     74  99  74  99  74 /  10  -   10  10  10
BURNET MUNI AIRPORT            74  96  74  96  74 /  30  -   10  10  10
DEL RIO INTL AIRPORT           78  97  78  98  77 /  20  20  20  10  10
GEORGETOWN MUNI AIRPORT        76  98  75  98  75 /  30  -   10  10  10
HONDO MUNI AIRPORT             74  97  74  98  74 /  10  -   10  10  10
SAN MARCOS MUNI AIRPORT        75  98  74  98  74 /  10  -   10  10  10
LA GRANGE - FAYETTE REGIONAL   78  98  77  98  77 /  10  20  10  20  10
SAN ANTONIO INTL AIRPORT       78  98  77  98  77 /  10  -   10  10  10
STINSON MUNI AIRPORT           76  98  76  99  77 /  10  -   10  10  10

&&

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

MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...32

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
514 AM CDT SUN AUG 17 2014

TXZ171>173-183>194-202>209-217>225-228-181015-
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-
514 AM CDT SUN AUG 17 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...TODAY AND TONIGHT.

HEAT INDICES ARE EXPECTED TO CLIMB INTO THE 103 TO 107 DEGREE
RANGE THIS AFTERNOON. THE HIGHEST HEAT INDEX READINGS WILL
GENERALLY BE SOUTH AND EAST OF A LINE FROM EAGLE PASS TO SAN
ANTONIO TO AUSTIN. OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED AT
THIS TIME.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

HEAT INDICES ARE EXPECTED TO CLIMB INTO THE 103 TO 108 DEGREE
RANGE ON MONDAY. THE HIGHEST HEAT INDEX READINGS WILL GENERALLY BE
SOUTH AND EAST OF A LINE FROM EAGLE PASS TO SAN ANTONIO TO AUSTIN.
OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
225 PM CDT SUN AUG 17 2014

TXZ183-172000-
VAL VERDE-
225 PM CDT SUN AUG 17 2014

...SIGNIFICANT WEATHER ADVISORY FOR VAL VERDE COUNTY UNTIL 300 PM
CDT...

AT 221 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 7 MILES SOUTHWEST OF
SEMINOLE CANYON STATE PARK TO 10 MILES SOUTHWEST OF AMISTAD
VILLAGE...AND MOVING NORTHEAST AT 15 MPH.

WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS...ALONG WITH
HEAVY RAIN AND FREQUENT DANGEROUS LIGHTNING.

LOCATIONS NEAR THE PATH OF THESE STORMS INCLUDE...
  COMSTOCK...
  SEMINOLE CANYON STATE PARK...
  AMISTAD VILLAGE...

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

THE HEAVY RAIN MAY FLOOD LOW LYING AREAS SUCH AS DITCHES...LOW WATER
CROSSINGS AND UNDERPASSES. DO NOT DRIVE YOUR VEHICLE ACROSS FLOODED
ROADWAYS.

LAT...LON 2984 10122 2945 10090 2936 10101 2946 10109
      2946 10115 2951 10119 2952 10127 2959 10126
      2957 10130 2959 10133 2964 10131 2965 10133
      2964 10136 2972 10141
TIME...MOT...LOC 1925Z 246DEG 12KT 2961 10138 2939 10115

JR