Severe Thunderstorm Warning 130, NWS Austin/San Antonio, TX

000 
WWUS54 KEWX 290309
SVSEWX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1008 PM CDT SAT MAY 28 2005

TXC163-325-290330-
/O.CON.KEWX.SV.W.0130.000000T0000Z-050529T0330Z/
MEDINA TX-FRIO TX-
1008 PM CDT SAT MAY 28 2005

...A SEVERE THUNDERSTORM WARNING CONTINUES UNTIL 1030 PM CDT FOR FRIO
AND MEDINA COUNTIES...

AT 1005 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A SOLID LINE OF STRONG TO SEVERE THUNDERSTORM CAPABLE OF 
PRODUCING NICKEL SIZE HAIL EXTENDING OVER THE WESTERN HALVES OF BOTH
FRIO AND MEDINA COUNTIES. THESE STORMS WERE MOVING EAST AT 20 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE DHANIS...MOORE...RIO
MEDINA...NATALIA...MICO...HONDO...DEVINE...CASTROVILLE AND BIG FOOT.

LAT...LON 2869 9934 2870 9884 2958 9884 2949 9901
      2955 9937

$$

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
859 PM CDT SAT MAY 28 2005

.UPDATE...A SRONG CLUSTER OF THUNDERSTORMS WITH GOOD UPPER SUPPORT
CAME OFF THE SIERRA MADRES LATE THIS AFTERNOON HAVE NOW SOLIDIFIED
INTO A STRONG BAND OF STORMS MOVING ACROSS THE RIO GRANDE PLAINS.
THESE SHOULD HOLD TOGETHER INTO THE CENTRAL PORTIONS OF OUR COUNTY
WARNING AREA...GIVEN THERMAL AND DEWPOINT ADVECTION CONSIDERATIONS.
A SEVERE THUNDERSTORM WATCH NUMBER 344 WAS SUBSEQUENTLY ISSUED
WHICH COVERS THE SOUTHWEST AND CENTRAL PORTIONS OF OUR COUNTY WARNING
AREA TIL MIDNIGHT.  FORECASTS AND GRIDS WERE AMENDED ACCORDINGLY.

&&

.PREV DISCUSSION... /ISSUED 735 PM CDT SAT MAY 28 2005/

UPDATE...UPDATED GRIDS TO ADD SEVERE THUNDERSTORM WATCH NUMBER
343 AND CHANGE TO SEVERE WORDING AS APPROPRIATE.  LLANO...BURNET AND
WILLIAMSON COUNTIES ARE IN THE WATCH TIL 12 MIDNIGHT.  CONVERGENT
BOUNDARY JUST NORTH OF THESE COUNTIES IN CENTRAL TEXAS EXPECTED TO
BE FOCUS FOR ADDITIONAL DEVELOPMENT AS UPPER 60S TO NEAR 70 DEWPOINTS
ADVECT INTO CONVERGENT ZONE. SOUTHWARD MOVING OUTFLOWS FROM STORMS
COULD ALSO CAUSE ACTIVITY TO BACKBUILD INTO COUNTIES COVERED IN THE
WATCH.

PREV DISCUSSION... /ISSUED 410 PM CDT SAT MAY 28 2005/

DISCUSSION...
TOUGH FORECAST WITH A VARIETY OF FORCING MECHANISMS FOR
CONVECTION. THE MAIN FORECAST ISSUES ARE POPS...HEAVY
RAIN...SEVERE...AND FLOOD THREAT TONIGHT AND SUNDAY...THEN
POPS TEMPS IN LATER PERIODS. THE MODELS ARE IN FAIR TO POOR
AGREEMENT AND PLAGUED WITH CONVECTIVE FEEDBACK. THE FORECAST IS
THEREFORE BASED MAINLY ON OBSERVED SATELLITE TRENDS FOR THE SHORT
TERM...AND THEN A MODEST APPROACH TO MODEL TIMING IN LATER
PERIODS.

SATELLITE IMAGERY SHOWS AN MCV CENTERED NEAR HOBBS...AND AN
APPROACHING JET STREAK/VORT LOBE OVER NORTHERN MEXICO. THERE ARE
ALSO LEFT OVER BOUNDARIES FROM CONVECTION EARLIER TODAY. THE
UPSHOT FOR OUR AREA IS SCATTERED SHOWERS AND THUNDERSTORMS TONIGHT
THROUGH MONDAY...THEN MORE TYPICAL AFTERNOON CONVECTION TUESDAY
THROUGH THURSDAY...BEFORE HOT AND DRY CONDITIONS LATE IN THE WEEK.

HAVE ISSUED A FLASH FLOOD WATCH FOR VAL VERDE...KINNEY...AND
EDWARDS COUNTIES THROUGH SUNDAY MORNING. THIS MAY NEED TO BE
EXTENDED IN TIME AND EXPANDED FURTHER EAST. RAINFALL AMOUNTS WILL
NOT LIKELY BE EXCESSIVE...BUT RECENT RAINFALL IN THAT AREA LEAVES
THE GROUND NEAR SATURATION...HENCE NEARLY ANY RAIN OVER 1/2 INCH
IN 30-60 MINUTES WILL CREATE FLOODING PROBLEMS. THE MAIN SHORT WAVE
TROUGH WILL EJECT OVER THE AREA SUNDAY/MONDAY...SO HAVE KEPT HIGH
POPS IN THROUGH MONDAY AFTERNOON.

THE MAIN U.S. LONGWAVE TROUGH WILL RETROGRADE TO THE WESTERN U.S.
DURING THE WEEK...WITH WEAK RIDGING OVER TEXAS. THIS SHOULD
PROVIDE FOR HIGHER MAX TEMPS AND LOWER POPS AS THE WEEK PROGRESSES.

EWX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH IN EFFECT FROM 7 PM SATURDAY UNTIL 7 AM CDT
      SUNDAY FOR THE FOLLOWING COUNTIES...EDWARDS...KINNEY...AND
      VAL VERDE.

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
TX...FLASH FLOOD WATCH IN EFFECT FROM 8 PM SATURDAY UNTIL 7 AM CDT
      SUNDAY FOR THE FOLLOWING COUNTIES...EDWARDS...KINNEY...AND
      VAL VERDE.

&&

02/09