FXUS64 KEWX 010521
AFDEWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1121 PM CST MON NOV 30 2009
.DISCUSSION...
SEE AVIATION SECTION.
&&
.AVIATION...
BIGGEST CHANGE FROM PREVIOUS FORECAST IS AN AREA OF RAIN MOVING
THROUGH THE CENTRAL PORTION OF THE REGION. THIS WILL LIKELY MOVE
THROUGH THE SAN ANTONIO AREA DURING THE NEXT HOUR OR TWO AND
REDUCE CIGS/VIS TO MVFR CATEGORY BRIEFLY. A SECOND AREA OF RAIN
WILL MOVE THROUGH DRT WITH THE SAME RESULT. OTHERWISE LOOK FOR
MORE SIGNIFICANT RAIN TO MOVE INTO THE TERMINALS BETWEEN 10Z AND
14Z AND LAST THROUGH THE DAY. MVFR CIGS/VIS UNTIL RAIN ENDS TUE
EVENING.
&&
.PREV DISCUSSION... /ISSUED 829 PM CST MON NOV 30 2009/
UPDATE...
A DEVELOPING SURFACE LOW OVER THE WESTERN GULF WITH SHALLOW
OVERRUNNING GULF MOISTURE WAS PRODUCING MOSTLY LIGHT RAIN FROM
THE RIO GRANDE PLAINS TO THE COASTAL PRAIRIES LATE THIS EVENING.
AT THE SAME TIME..THE UPPER LEVEL STORM SYSTEM OVER NORTHERN
MEXICO CONTINUED TO EJECT DISTURBANCES NORTHEAST. THE AIR MASS OVER
SOUTH CENTRAL TEXAS REMAINS QUITE DRY SO RAIN AMOUNTS SHOULD BE
LIGHT TONIGHT WITH RAIN CHANCES INCREASING FROM SOUTHWEST TO
NORTHEAST OVERNIGHT AS THE UPPER LOW CONTINUES ITS MOVE TO THE
EAST. CURRENT FORECAST LOOKS GOOD AT PRESENT AND PLAN NO UPDATE.
PREV DISCUSSION... /ISSUED 525 PM CST MON NOV 30 2009/
DISCUSSION...
SEE AVIATION SECTION.
AVIATION...
VFR CIGS WILL CONTINUE AT ALL TERMINALS THROUGH MOST OF THE NIGHT.
RAIN AREA IS CURRENTLY SOUTH OF THE FORECAST AREA AND MOVING
SLOWLY NORTHWARD. EXPECT RAIN WILL REACH SAN ANTONIO AREA BY
AROUND 11Z...DRT BY 12Z...AND AUS BY 14Z. AS RAIN MOVES IN CIGS
AND VIS WILL DROP TO MVFR CATEGORY. RAIN IS EXPECTED TO LAST
THROUGH THE DAY TOMORROW.
PREV DISCUSSION... /ISSUED 328 PM CST MON NOV 30 2009/
DISCUSSION...
WINTER WEATHER IS NOT EXPECTED ACROSS OUR AREA OVERNIGHT.
WET AND COLD CONDITIONS ARE IN STORE AGAIN TONIGHT AND TUESDAY AS
THE UPPER LOW ACROSS NORTHERN MEXICO CONTINUES TO APPROACH TEXAS.
INTERMITTENT LIGHT RAIN CAN BE EXPECTED OVERNIGHT ESPECIALLY
ACROSS THE WESTERN HALF OF THE REGION. LOWS WILL REMAIN IN THE MID
AND UPPER 40S WITH A FEW LOWER 40 READINGS ACROSS THE HILL
COUNTRY. CLOUDY SKIES WILL CONTINUE THROUGH TUESDAY WITH HIGH
TEMPERATURES GENERALLY ONLY A HANDFUL OF DEGREES WARMER THAN THE
MORNING LOWS. PERIODS OF RAIN ARE ONCE AGAIN IN STORE WITH THE
HIGHEST LIKELIHOODS GRADUALLY SHIFTING EAST THROUGHOUT THE DAY.
CHANCES FOR RAIN WILL DECREASE FROM WEST TO EAST LATE TUESDAY AS
THE UPPER LOW EJECTS TO THE NORTHEAST. TEMPERATURES TUESDAY NIGHT
AND EARLY WEDNESDAY WILL BE COLD ENOUGH ACROSS THE HILL COUNTRY
AND EDWARDS PLATEAU TO SUPPORT A MIX OF RAIN AND LIGHT SNOW
POTENTIALLY BECOMING ONLY LIGHT SNOW DURING THE WEE HOURS OF
WEDNESDAY MORNING. A LIGHT DUSTING OF SNOW IS POSSIBLE ACROSS THE
HIGHER ELEVATIONS BUT WOULD BE VERY SHORT-LIVED AS SURFACE
CONDITIONS ARE TOO WARM AND WET TO SUPPORT ACCUMULATIONS.
SKIES BEGIN TO CLEAR ON WEDNESDAY WITH TEMPERATURES REACHING NEAR
50 ACROSS THE HILL COUNTRY TO MID-50S ELSEWHERE ACROSS THE REGION.
GOOD RADIATIONAL COOLING IS EXPECTED TO DROP TEMPERATURES INTO THE
30S AREA-WIDE THURSDAY MORNING WITH A FREEZE ACROSS THE HILL
COUNTRY. SEASONABLY COOL TEMPERATURES ARE EXPECTED THROUGH THE
REST OF THE WORK WEEK.
THE TRICKIEST PART OF THE FORECAST IS LATE IN THE WEEK AS ANOTHER
UPPER LOW SWINGS ACROSS THE GREAT LAKES REGION. THERE IS DECENT
MODEL CONSENSUS AS FAR AS BRINGING ANOTHER FRONT INTO OUR REGION.
HOWEVER...THERE IS A MAJOR DIVERGENCE ON HOW FAR SOUTH AND HOW
POTENT THIS SYSTEM WOULD BE FOR US. THE 12Z RUN OF THE GFS IS THE
MOST BULLISH AND BRINGS SNOW TO THE ENTIRE CWA ON FRIDAY AND
TEMPERATURES DROPPING INTO THE UPPER 20S SATURDAY MORNING. WITH
THE GFS PROVIDING A MUCH DIFFERENT SOLUTION FROM ITS PREVIOUS
RUN...HAVE SIDED MORE WITH THE ECMWF WHICH INDICATES THE SAME
BASIC SYNOPTIC PATTERN BUT IS NOT AS EXTREME WITH PRECIP CHANCES
NOR TEMPERATURES. SINCE THE GFS SOLUTION IS POSSIBLE...BUT NOT
PROBABLE...THE FORECAST FOR THE END OF THE WEEK BEARS WATCHING.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 43 46 42 52 36 / 50 100 70 20 -
AUSTIN BERGSTROM INTL AIRPORT 45 49 38 54 32 / 50 100 70 20 -
NEW BRAUNFELS MUNI AIRPORT 44 48 43 55 34 / 70 100 60 10 -
BURNET MUNI AIRPORT 42 45 37 48 32 / 40 90 70 20 -
DEL RIO INTL AIRPORT 44 50 37 57 35 / 80 70 10 0 -
GEORGETOWN MUNI AIRPORT 42 47 39 50 34 / 40 100 80 20 -
HONDO MUNI AIRPORT 45 50 35 57 35 / 70 90 30 - -
SAN MARCOS MUNI AIRPORT 44 48 38 55 35 / 60 100 70 10 -
LA GRANGE - FAYETTE REGIONAL 45 49 44 55 37 / 50 100 90 20 -
SAN ANTONIO INTL AIRPORT 45 48 43 56 36 / 70 100 50 - -
STINSON MUNI AIRPORT 46 50 41 57 35 / 70 100 40 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
02/05