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000
FXUS64 KEWX 220105
AFDEWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
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              90  68  92  71  93 /  30  40  -    0   0
AUSTIN BERGSTROM INTL AIRPORT  91  68  91  69  92 /  30  40  -    0   0
NEW BRAUNFELS MUNI AIRPORT     91  68  92  70  93 /  20  40  -    0   0
BURNET MUNI AIRPORT            86  64  90  68  91 /  30  30  -    0   0
DEL RIO INTL AIRPORT           96  71  97  74  98 /  10  10  10   0   0
GEORGETOWN MUNI AIRPORT        86  66  89  71  90 /  30  40  -    0   0
HONDO MUNI AIRPORT             90  69  95  71  96 /  20  30  -    0   0
SAN MARCOS MUNI AIRPORT        90  69  90  70  91 /  30  40  -    0   0
LA GRANGE - FAYETTE REGIONAL   90  74  91  73  91 /  20  50  10   0   0
SAN ANTONIO INTL AIRPORT       92  70  92  73  93 /  20  30  -    0   0
STINSON MUNI AIRPORT           91  70  92  72  93 /  20  30  -    0   0

&&

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

$$

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