Area Forecast Discussion

000
FXUS64 KEWX 050040 AAA
AFDEWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
640 PM CST SAT FEB 4 2012

.DISCUSSION...
ELEVATED CONVECTION INCREASING ACROSS THE CWFA...ESPECIALLY SOUTH
OF HIGHWAY 90. CONVECTION IS IN RESPONSE TO THE SUB-TROPICAL JET
STREAK AND ASSOCIATED LARGE SCALE ASCENT. ISOLATED THUNDERSTORMS
WILL ALSO OCCUR ACROSS OUR SOUTHERN COUNTIES TONIGHT. UPDATED FCST
TO INCREASE POPS AND ADD THUNDERSTORMS.

&&

.PREV DISCUSSION... /ISSUED 559 PM CST SAT FEB 4 2012/

AVIATION...
SOUTHWESTERLY SUBTROPICAL JET STREAK WILL SWEEP INCREASING MID AND
UPPER LEVEL MOISTURE AND INSTABILITY NORTHEAST ACROSS THE REGION
TONIGHT AND EARLY SUNDAY WITH INCREASING CHANCES FOR LIGHT
SHOWERS AND EVEN SOME ISOLATED ELEVATED THUNDERSTORMS ABOVE A
RELATIVELY DRY AIR MASS. I-35 CORRIDOR VFR CIGS WITH OCNL LIGHT
RAIN SHOWERS AFTER 08Z LOCALLY LOWERING CIGS AND VSBYS. KDRT
TERMINAL VFR CIGS VSBYS UNRSTD WITH WIDELY SCATTERED SHOWERS AFTER
MIDNIGHT LOCALLY LOWERING CIGS AND VSBYS.

PREV DISCUSSION... /ISSUED 313 PM CST SAT FEB 4 2012/

DISCUSSION...
MOSTLY CLOUDY TO CLOUDY CONDITIONS WILL CONTINUE INTO THE
OVERNIGHT HOURS AND THROUGH SUNDAY AS UPPER LEVEL MOISTURE FROM
THE PACIFIC STREAMS INTO THE REGION. THE CLOUD COVER AND WET SOILS
WILL HELP KEEP LOW TEMPERATURES MOSTLY IN THE 40S SUNDAY MORNING.
THE UPPER MOISTURE OVERRUNNING THE COOL AIR AT THE SURFACE WILL
RESULT IN A DAMP AND CHILLY DAY SUNDAY...WITH TEMPERATURES IN THE
LOW 50S AND OCCASIONAL LIGHT RAIN. DUE TO THE STRATIFORM NATURE OF
THE PRECIPITATION...QPF WILL BE LOW...GENERALLY A FEW HUNDREDTHS
TO ONE TENTH OF AN INCH. COOLER TEMPERATURES WILL SETTLE IN SUNDAY
NIGHT AS THE MID-LEVELS BEGIN TO DRY AND RAIN CHANCES END.

MONDAY WILL BE DRY AND SEASONABLY COOL...WITH TEMPERATURES WARMING
CLOSER TO AVERAGE BY TUESDAY. A MOISTENING TREND IS EXPECTED
DURING THE MIDDLE OF THE WEEK AS AN UPPER TROUGH SLIDES ACROSS THE
GREAT PLAINS. MEANWHILE...AN UPPER LOW WILL PUSH SOUTHWARD ALONG
THE U.S. PACIFIC COAST TOWARD BAJA CALIFORNIA. MODELS ARE IN GOOD
OVERALL CONSENSUS WITH THIS SYSTEM...BUT STILL DISAGREE SOMEWHAT
ON HOW FAR EAST TO BRING THE LOW AS WELL AS WHEN TO EJECT IT
EASTWARD OVER CENTRAL MEXICO/SOUTH TEXAS. THE GFS AND ECMWF ARE IN
AGREEMENT WITH THE TRACK OF THE LOW UNTIL THE LATE FRI/SAT TIME
FRAME. THE GFS PREFERS TO BRING THE LOW ACROSS CENTRAL MEXICO AND
DEVELOPS THE SYSTEM INTO AN OPEN WAVE EARLY SATURDAY WHILE THE
ECMWF IS SLOWER BY ABOUT 36 HRS. MEANWHILE...THE CMC (CANADIAN)
KEEPS THE TRACK OF THE LOW FURTHER WEST AND BEGINS TO PUSH THE
SYSTEM WESTWARD ON FRIDAY. HAVE GONE WITH A SOLUTION CLOSER TO THE
AVERAGE OF THE GFS/ECMWF. WHAT THIS MEANS IS THAT AS THE LOW
REMAINS OVER THE BAJA...IT WILL DRAW GULF MOISTURE INTO SOUTH
CENTRAL TEXAS AND LEAD TO CHANCES FOR RAIN DURING THE LATTER HALF
OF THE WEEK. THIS PATTERN IS MORE STRATIFORM/OVERRUNNING IN NATURE
THAN CONVECTIVE...SO HAVE NOT MENTIONED THUNDERSTORMS NOR GONE
WITH SIGNIFICANT RAIN AMOUNTS AT THIS TIME. A DRYING TREND IS
INDICATED AT THE TAIL-END OF THE FORECAST...BUT IS DEPENDENT UPON
THE ASSUMPTION THAT THE UPPER LOW/OPEN TROUGH WILL BE EAST OF
TEXAS BY THEN.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              43  53  39  59  40 /  20  40  10  10  10
AUSTIN BERGSTROM INTL AIRPORT  43  54  36  57  36 /  20  40  10  10  10
NEW BRAUNFELS MUNI AIRPORT     43  53  38  59  38 /  20  40  10  10  10
BURNET MUNI AIRPORT            40  51  37  55  38 /  20  20  -   -   10
DEL RIO INTL AIRPORT           45  55  39  61  40 /  20  10  -    0  -
GEORGETOWN MUNI AIRPORT        39  53  35  58  37 /  20  20  -   -   10
HONDO MUNI AIRPORT             44  54  38  60  38 /  20  40  -   10  10
SAN MARCOS MUNI AIRPORT        44  52  39  58  39 /  20  40  10  10  10
LA GRANGE - FAYETTE REGIONAL   44  52  40  58  42 /  30  50  20  10  10
SAN ANTONIO INTL AIRPORT       45  53  41  59  42 /  20  40  10  10  10
STINSON MUNI AIRPORT           46  53  41  59  40 /  20  50  10  10  10

&&

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

$$

MESOSCALE/AVIATION...02
SYNOPTIC/GRIDS...13
PUBLIC SERVICE/DATA COLLECTION...31