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000
FXUS64 KEWX 220434
AFDEWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1134 PM CDT TUE MAY 21 2013

.AVIATION...
A 500 HPA TROF MOVING TO THE EASTERN PART OF TEXAS TONIGHT
OPENED THE GATE FOR A COLD FRONT TO MOVE ACROSS SOUTH CENTRAL
TEXAS FROM THE NORTH TONIGHT. SCATTERED SHRA AND ISOLD TSRA
OVER THE EAST TO SOUTHEAST PART OF SOUTH CENTRAL TEXAS WILL MOVE
SOUTHEAST. AS THE 500 HPA TROF MOVES FURTHER EAST ON WEDNESDAY
MORNING AND TO THE LOWER MS VALLEY BY WEDNESDAY AFTERNOON...MORE
STABLE CONDITIONS WILL DEVELOP OVER SOUTH CENTRAL TEXAS FROM THE
WEST...WITH DRY AND WARM WEATHER EXPECTED WEDNESDAY. THROUGH 08Z
CIGS NEAR 4 THSD TO 6 THSD BKN VCNTY OF KAUS TO KSAT AND KSSF AND
A FEW CLOUDS ABOVE 25 THSD FT VCNTY OF KDRT ARE EXPECTED.  AFTER
08Z A FEW CLOUDS AT 5 THSD TO 10 THSD FT VCNTY OF KAUS TO KSAT
AND KSSF AND SCT CIRRUS ABOVE 25 THSD FT VCNTY OF KDRT IS FORECAST.
AFTER 15Z WEDNESDAY VFR CONDITIONS WILL CONTINUE...WITH A FEW
CLOUDS AROUND 5 THSD FT AND FEW TO SCT CIRRUS ABOVE 25 THSD FT.

&&

.PREV DISCUSSION... /ISSUED 838 PM CDT TUE MAY 21 2013/

UPDATE...
CONTINUED TO SHOW DECREASING CHANCES OF SHOWERS AND THUNDERSTORMS
FROM THE WEST TONIGHT...AS THE 700 TO 200 HPA TROF CONTINUES TO
MOVE EAST OF SOUTH CENTRAL TEXAS...TAKING THE ENERGY TO PRODUCE
THUNDERSTORMS TO THE EAST. MORE STABLE CONDITIONS WILL CONTINUE
TO INCREASE ACROSS SOUTH CENTRAL TEXAS LATE TONIGHT THROUGH
WEDNESDAY...BRINGING DRY AND WARM WEATHER FOR WEDNESDAY AND
THURSDAY. REMOVED THE MENTION OF SEVERE THUNDERSTORMS FROM THE
FORECAST FOR TONIGHT...AS THE ENERGY FOR SEVERE STORMS HAS MOVED
EAST OF SOUTH CENTRAL TEXAS.

PREV DISCUSSION... /ISSUED 805 PM CDT TUE MAY 21 2013/

UPDATE...
ADJUSTED POPS TO SHOW A TREND OF DECREASING CHANCES OF RAIN FROM
THE WEST AND NORTHWEST THIS EVENING...AND CONTINUING THROUGH
TONIGHT.  THE 500 HPA TROF IS BEGINNING TO MOVE EAST OF SOUTH
CENTRAL TEXAS...TAKING THE ENERGY TO PRODUCE THUNDERSTORMS TO
THE EAST.  MORE STABLE CONDITIONS WILL CONTINUE TO INCREASE
ACROSS SOUTH CENTRAL TEXAS LATE TONIGHT THROUGH WEDNESDAY...
BRINGING DRY AND WARM WEATHER FOR WEDNESDAY AND THURSDAY.

PREV DISCUSSION... /ISSUED 627 PM CDT TUE MAY 21 2013/

DISCUSSION...

SEE AVIATION FOR 00Z TAFS.

AVIATION...
A 500 HPA TROF FROM THE NORTHERN PLAINS TO SOUTH CENTRAL TEXAS
WILL MOVE TO EASTERN TEXAS BY LATE THIS EVENING AND TO THE
LOWER MS VALLEY ON WEDNESDAY. THIS WILL OPEN THE GATE FOR A
WEAK COLD FRONT TO MOVE ACROSS SOUTH CENTRAL TEXAS TONIGHT.
THROUGH 06Z SCT SHRA/TSRA ARE EXPECTED TO DEVELOP OVER
SOUTH CENTRAL TEXAS ALONG AND EAST OF A LINE FROM NEAR
KGTU TO KAUS TO KSAT TO KPEZ. WEST OF THIS LINE ISOLATED
EARLY EVENING SHRA/TSRA ARE POSSIBLE IN WAKE OF DAYTIME
HEATING...AND WITH THE WIND SHIFT COMING ACROSS THE WEST
PART OF SOUTH CENTRAL TEXAS FROM THE NORTH. AFTER 06Z MORE
STABLE CONDITIONS WILL DEVELOP OVER SOUTH CENTRAL TEXAS...AS
RIDGING ALOFT INCREASES FROM THE WEST. THIS WILL CAUSE DRIER AND
WARMER WEATHER FOR THE AREA ON WEDNESDAY...WITH VFR CONDITIONS
ACROSS THE AREA.

PREV DISCUSSION... /ISSUED 255 PM CDT TUE MAY 21 2013/

SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...
A FRONTAL BOUNDARY STRETCHING FROM NEAR DENTON TO SAN ANGELO TO
FORT STOCKTON WILL BE THE PRIMARY FOCUS OF THUNDERSTORM
DEVELOPMENT THIS AFTERNOON AND EVENING. THE ATMOSPHERE IS QUITE
UNSTABLE OVER SOUTH CENTRAL TEXAS. SURFACE WINDS FROM THE SOUTH
HAVE BROUGHT MOIST GULF AIR WITH DEW POINTS AROUND 70. COLD AIR IN
THE MID-LEVELS HAS STEEPENED LAPSE RATES. SPC MESO-ANALYSIS SHOWS CAPE
ABOVE 3000 J/KG ACROSS MUCH OF THE FORECAST AREA. EXPECTING STORMS
TO MOVE IN TO OUR CWA LATE THIS AFTERNOON AND EVENING. ANY STORMS MAY
BECOME SEVERE AND THE MAIN THREATS WILL BE FOR LARGE HAIL AND
DAMAGING WIND GUSTS WITH A SLIGHT THREAT FOR TORNADOES. MOST
CONVECTION SHOULD BE OVER BY 2AM...BUT ISOLATED THUNDERSTORMS
COULD LINGER OVERNIGHT ESPECIALLY OVER THE SOUTHEAST. THE FRONT
WILL DISSIPATE WEDNESDAY AND THE UPPER LEVEL TROUGH WILL MOVE OFF
TO THE EAST. THIS WILL END ANY PRECIP CHANCES. A MID TO UPPER
LEVEL RIDGE WILL BEGIN TO BUILD OVER THE SOUTHERN PLAINS WEDNESDAY
EVENING.

LONG TERM (THURSDAY THROUGH TUESDAY)...
THE MID TO UPPER LEVEL RIDGE WILL BUILD ACROSS THE CENTRAL PART OF
THE COUNTRY THROUGH THE END OF THE WEEK. THE LOW LEVEL FLOW WILL
CONTINUE TO BE FROM THE SOUTH TO SOUTHEAST. THIS WILL PUT US BACK
INTO THE WARM...MOIST PATTERN WITH OVERNIGHT/MORNING CLOUDS OVER
THE EASTERN HALF OF THE AREA FOLLOWED BY AFTERNOON/EVENING
CLEARING. TEMPERATURES WILL BE ABOVE NORMAL. RAIN CHANCES WILL BE
NEARLY ZERO. THE ONE POSSIBILITY FOR ANY RAIN IS A SHORT WAVE
TROUGH MODELS MOVE THROUGH THE UPPER PATTERN FRIDAY/SATURDAY. BOTH
GFS AND ECMWF SHOW A CHANCE FOR PRECIP OVER THE WESTERN PART OF
THE CWA. HOWEVER...HAVE DISCOUNTED THIS SINCE LOW LEVEL MOISTURE
WILL BE SHALLOW AND UPPER RIDGE LOOKS STRONG.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              68  92  71  93  72 /  20  -    0   0  10
AUSTIN BERGSTROM INTL AIRPORT  68  91  69  92  70 /  20  -    0   0  10
NEW BRAUNFELS MUNI AIRPORT     68  92  70  93  71 /  20  -    0   0  10
BURNET MUNI AIRPORT            64  90  68  91  69 /  10  -    0   0  10
DEL RIO INTL AIRPORT           71  97  74  98  75 /  10  10   0   0  10
GEORGETOWN MUNI AIRPORT        66  89  71  90  72 /  20  -    0   0  10
HONDO MUNI AIRPORT             69  95  71  96  72 /  10  -    0   0  10
SAN MARCOS MUNI AIRPORT        69  90  70  91  71 /  20  -    0   0  10
LA GRANGE - FAYETTE REGIONAL   74  91  73  91  74 /  50  10   0   0  -
SAN ANTONIO INTL AIRPORT       70  92  73  93  74 /  20  -    0   0  10
STINSON MUNI AIRPORT           70  92  72  93  73 /  20  -    0   0  10

&&

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

$$

MESOSCALE/AVIATION...08
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...33