Area Forecast Discussion Issued by NWS Austin/San Antonio, TX
000
FXUS64 KEWX 212327
AFDEWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
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 92 68 92 71 93 / 30 40 - 0 0
AUSTIN BERGSTROM INTL AIRPORT 93 68 91 69 92 / 30 40 - 0 0
NEW BRAUNFELS MUNI AIRPORT 92 68 92 70 93 / 20 40 - 0 0
BURNET MUNI AIRPORT 88 64 90 68 91 / 30 40 - 0 0
DEL RIO INTL AIRPORT 95 71 97 74 98 / 10 10 10 0 0
GEORGETOWN MUNI AIRPORT 88 66 89 71 90 / 30 40 - 0 0
HONDO MUNI AIRPORT 92 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 91 74 91 73 91 / 20 50 10 0 0
SAN ANTONIO INTL AIRPORT 92 70 92 73 93 / 20 40 - 0 0
STINSON MUNI AIRPORT 92 70 92 72 93 / 20 40 - 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...08/24
SYNOPTIC/GRIDS...17/05
PUBLIC SERVICE/DATA COLLECTION...33