HAMweather.com Area Forecast Discussion for County Warning Area EWX

Thu, 16 Feb 2012 07:26:27 GMT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1210 AM CST THU FEB 16 2012

.UPDATE...
ADJUSTED FORECASTS TO SHOW DENSE FOG ADVISORY FOR PARTS OF FAYETTE...
LAVACA AND DEWITT COUNTIES UNTIL 4 AM...WHERE AREAS OF DENSE FOG
ARE EXPECTED TO CONTINUE FOR THE NEXT FEW HOURS. A COLD FRONT TO
THE NORTHWEST OF THESE AREAS IS FORECAST TO DRIFT SOUTHEAST
TONIGHT...IMPROVING THE FOG CONDITIONS AFTER 4 AM...AS DRIER
CONDITIONS DEVELOP ACROSS FAYETTE...LAVACA AND DEWITT COUNTIES
FORM THE NORTH AND NORTHWEST. CONTINUED TRENDS WITH ONGOING FORECASTS.
COOLER AIR IS STILL EXPECTED TO COME ACROSS SOUTH CENTRAL TEXAS
TONIGHT THROUGH FRIDAY MORNING. THE RESULTING COLD FRONT IS STILL
FORECAST TO BE NEAR THE COAST THURSDAY THROUGH FRIDAY...AS A
SERIES OF S/W TROFS PASS OVER SOUTH CENTRAL TEXAS FROM THE
SOUTHWEST. CONSIDERABLE CLOUDINESS WILL FORM THURSDAY AND PERSIST
THURSDAY NIGHT THROUGH FRIDAY...A TREND FOR THE LATE FALL OF 2011
AND SO FAR FOR THE WINTER OF 2011/2012. FORECAST SOLUTIONS
CONTINUE TO MOVE THE 500 HPA LOW ACROSS SOUTH CENTRAL TEXAS ON
SATURDAY... IN A SIMILAR WAY THAT THE 500 HPA TROF MOVED OVER THE
AREA EARLIER TODAY. CONTINUED TRENDS OF RAIN CHANCES FOR
SATURDAY... WITH BETTER RAIN CHANCES OVER THE EAST TO SOUTHEAST
PART OF SOUTH CENTRAL TEXAS...AS SHOWN WELL BY ONGOING FORECASTS.
DRIER WEATHER STILL SHOWS UP IN SOLUTIONS FOR SATURDAY NIGHT AND
SUNDAY. INCREASING CLOUDS ARE EXPECTED MONDAY AND TUESDAY...
FOLLOWED BY A FEW DAYS OF DRIER WEATHER AGAIN LATE NEXT WEEK.

.PREV DISCUSSION... /ISSUED 1133 PM CST WED FEB 15 2012/ 

AVIATION...
FLYING CONDITIONS WILL BE VFR FOR THE NEXT 24 HOURS AS A COLD
FRONT MOVES AWAY FROM THE AREA. WE WILL SEE HIGH CLOUDS THROUGH
THE OVERNIGHT HOURS. EARLY THU MORNING A MID-LEVEL CLOUD DECK
WILL BUILD IN WITH CIGS AROUND 10K FEET. BY THE END OF THE
PERIOD...THERE WILL BE CHANCE FOR RAIN WITH MVFR CIGS AT THE I35
TERMINALS AS ANOTHER WEATHER SYSTEM APPROACHES THE AREA FROM THE
SOUTH. HAVE INCLUDED A PROB30 GROUP TO ACCOUNT FOR THIS AS CHANCES
ARE LOW AT THIS TIME. FOR AUS AND SAT EXPECT RA AND MVFR CIGS TO
MOVE IN AROUND 09Z ON FRI.

PREV DISCUSSION... /ISSUED 909 PM CST WED FEB 15 2012/ 

DISCUSSION...
CONTINUED TRENDS WITH ONGOING FORECASTS.  COOLER AIR IS STILL
EXPECTED TO COME ACROSS SOUTH CENTRAL TEXAS TONIGHT THROUGH
FRIDAY MORNING.  THE RESULTING COLD FRONT IS STILL FORECAST
TO BE NEAR THE COAST THURSDAY THROUGH FRIDAY...AS A SERIES
OF S/W TROFS PASS OVER SOUTH CENTRAL TEXAS FROM THE SOUTHWEST.
CONSIDERABLE CLOUDINESS WILL FORM THURSDAY AND PERSIST THURSDAY
NIGHT THROUGH FRIDAY...A TREND FOR THE LATE FALL OF 2011 AND
SO FAR FOR THE WINTER OF 2011/2012.  FORECAST SOLUTIONS CONTINUE
TO MOVE THE 500 HPA LOW ACROSS SOUTH CENTRAL TEXAS ON SATURDAY...
IN A SIMILAR WAY THAT THE 500 HPA TROF MOVED OVER THE AREA
EARLIER TODAY.  CONTINUED TRENDS OF RAIN CHANCES FOR SATURDAY...
WITH BETTER RAIN CHANCES OVER THE EAST TO SOUTHEAST PART OF
SOUTH CENTRAL TEXAS...AS SHOWN WELL BY ONGOING FORECASTS.
DRIER WEATHER STILL SHOWS UP IN SOLUTIONS FOR SATURDAY NIGHT
AND SUNDAY. INCREASING CLOUDS ARE EXPECTED MONDAY AND TUESDAY...
FOLLOWED BY A FEW DAYS OF DRIER WEATHER AGAIN LATE NEXT WEEK.

PREV DISCUSSION... /ISSUED 305 PM CST WED FEB 15 2012/

DISCUSSION...
AT 21Z A PACIFIC FRONTAL SYSTEM WAS MOVING SOUTHEASTWARD ACROSS
OUR SOUTHEAST COUNTIES USHERING IN A DRIER AIRMASS FOR TONIGHT.
ISOLATED CONVECTION IN ADVANCE OF THE FRONTAL BOUNDARY WILL BE
EAST OF OUR CWFA BY 6 PM. THE DRIER AIRMASS WILL ALLOW LOWS
TONIGHT TO RANGE FROM THE UPPER 30S ACROSS PORTIONS OF THE HILL
COUNTRY TO LOWER 50S SOUTHEAST.

THURSDAY WILL START OUT ON THE COOL SIDE WITH A NICE WARMUP IN THE
AFTERNOON. HIGH ARE EXPECTED TO BE IN THE MID 60S TO NEAR 70. LOW
CLOUDS WILL INCREASE FROM THE SOUTH DURING THE LATE AFTERNOON AS
MOISTURE ABOVE THE BOUNDARY LAYER INCREASES IN RESPONSE TO THE
APPROACH OF THE NEXT UPPER LEVEL TROF. SHOWERS WILL THEN DEVELOP
AND SPREAD NORTHWARD ACROSS OUR CWFA THURSDAY NIGHT AS WAA
INCREASES ACROSS SOUTH TEXAS. THE CLOUDY AND SHOWERY CONDITIONS
WILL PERSIST ON FRIDAY AS SOUTH CENTRAL TEXAS REMAINS IN THE WARM
SECTOR. CLOUDS AND SHOWERS WILL KEEP AFTERNOON HIGHS IN THE UPPER
50S NORTH TO MID 60S SOUTH.

SHOWERS AND THUNDERSTORMS WILL INCREASE DRAMATICALLY FRIDAY INTO
SATURDAY. THE UPPER LEVEL TROF CURRENTLY LOCATED OVER SOUTHERN 
UTAH WILL MOVE ACROSS SOUTH CENTRAL TEXAS ON SATURDAY. THE MODELS
AGREE ON THE TIMING BUT NOT THE STRENGTH. THE NAM12 AND CMC BRING
A BOWLING BALL CLOSED LOW ACROSS WHILE THE GFS AND ECMWF BRING
ACROSS AN OPEN TROF. EITHER WAY THERE WILL BE AMPLE SYNOPTIC SCALE
LIFT TO SUPPORT THUNDERSTORMS. THE ONE CAVEAT TO THIS RAIN EVENT
IS THE DEVELOPMENT OF A SFC LOW ALONG THE MIDDLE TEXAS COAST WHICH
WILL RESULT IN A EAST TO NORTHEAST SFC FLOW. THIS MEANS MUCH OF
THE CONVECTION WILL BE ELEVATED WITH SFC BASED STORMS LIKELY
ACROSS OUR SOUTHEAST COUNTIES. THE GREATEST THREAT FOR STRONG
THUNDERSTORMS AND HEAVY RAINFALL WILL BE ACROSS OUR SOUTHEAST
COUNTIES. HOWEVER STILL CANNOT RULE OUT SMALL HAIL FROM THE
STRONGER ELEVATED STORMS. RAIN CHANCES WILL END BY SATURDAY
EVENING WITH THE PASSAGE OF THE UPPER LEVEL TROF AXIS.

THE FIRST HALF OF NEXT WEEK WILL BE MILD WITH TEMPERATURES SLIGHTLY
ABOVE SEASONAL NORMS. THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS SOUTHEAST ON TUESDAY ASSOCIATED WITH ANOTHER WEAK
FRONTAL PASSAGE.

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              48  60  50  61  39 /  30  30  70  40  10 
AUSTIN BERGSTROM INTL AIRPORT  47  60  50  60  38 /  30  30  70  40  10 
NEW BRAUNFELS MUNI AIRPORT     50  60  52  64  41 /  30  40  70  40  10 
BURNET MUNI AIRPORT            45  58  45  56  36 /  20  20  60  40  10 
DEL RIO INTL AIRPORT           48  60  49  64  43 /  20  30  40  10  -  
GEORGETOWN MUNI AIRPORT        46  57  48  58  37 /  20  30  70  40  10 
HONDO MUNI AIRPORT             49  60  50  64  39 /  30  40  70  30  -  
SAN MARCOS MUNI AIRPORT        49  60  51  63  40 /  30  40  70  40  10 
LA GRANGE - FAYETTE REGIONAL   51  61  52  63  42 /  30  40  80  60  10 
SAN ANTONIO INTL AIRPORT       50  60  52  64  42 /  30  40  70  30  10 
STINSON MUNI AIRPORT           51  60  52  65  42 /  30  40  70  30  10 

.EWX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 4 AM CST EARLY THIS MORNING FOR THE 
FOLLOWING COUNTIES: DE WITT...FAYETTE...LAVACA.