Freeze Warning 3, NWS Austin/San Antonio, TX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1036 AM CDT MON OCT 24 2005

.UPDATE...
NWS RADARS INDICATE SHOWERS HAVE MOVED SOUTH OF THE AREA WHILE NWS
SATELLITE IMAGERY SHOWS CLEARING SLIDING SOUTHWEST AROUND 15 MPH
ACROSS THE AREA. UPDATED TO REMOVE POPS. ALSO MINOR UPDATES TO THE
OTHER PARAMETERS FOR TODAY TO REFLECT ONGOING TRENDS. OTHERWISE,
REMAINDER OF SOUTH CENTRAL TEXAS FORECASTS GENERALLY ON TRACK.

&&

.PREV DISCUSSION... (ISSUED 401 AM CDT MON OCT 24 2005)

DISCUSSION...
A COLD AND DAMP START TO THE WEEK ACROSS SOUTH CENTRAL TEXAS EARLY
THIS MORNING. THE MAIN FORECAST ISSUES ARE TRENDING OUT RAIN AND
CLOUDS THIS MORNING...MIN TEMPS TUE MORNING...AND WEAK RETURN FLOW
POPS THU-FRI. THE 00Z NCEP MODELS ARE IN GOOD AGREEMENT WITH
GENERAL MASS FIELDS...BUT THE MOS VALUES DIFFER WILDLY BETWEEN
MODELS...AND ARE INCONSISTENT FROM STATION TO STATION FOR ANY
GIVEN MOS. OVERALL...THE NAM MOS IS CLOSEST TO REALITY FOR TODAY
AND TONIGHT...THEN WILL TREND ALONG WITH THE GFS MOS FOR THE REST
OF THE FORECAST.

ISENTROPIC LIFT ON THE 305K SFC SEEMS BEST CORRELATED WITH
ELEVATED SHOWERS AND LIGHT RAIN ACROSS THE AREA. DRIER AIR WILL
SIFT IN FROM THE NORTHEAST AND THE ISENTROPIC LIFT WILL
END...CAUSING THE END OF POPS AROUND 16Z. RAINFALL AMOUNTS WILL BE
0.05 INCHES OR LESS...ENOUGH TO SNARL MONDAY MORNING RUSH HOUR
TRAFFIC...BUT NOT MUCH ELSE.

HIGH PRESSURE WILL BUILD IN THROUGHOUT THE DAY...MAINTAINING COLD
AIR ADVECTION AND THUS VERY COOL AFTERNOON TEMPS...EVEN WITH FULL
SUN IN THE NORTHEASTERN QUARTER. IT WILL BE SLOWEST TO CLEAR ALONG
THE RIO GRANDE PLAINS...HENCE LOWER 60S AFTERNOON TEMPS THERE. THE
SURFACE HIGH WILL BE CENTERED OVER SOUTH CENTRAL TEXAS
TONIGHT...ALLOWING FOR MAXIMUM RADIATIONAL COOLING AND THE COLDEST
TEMPS SINCE EARLY LAST SPRING. AS MENTIONED BEFORE...THE MOS IS
ALL OVER THE PLACE. BOTTOM LINE...A FEW SHELTERED VALLEYS IN THE
HILL COUNTRY MIGHT SEE A FEW HOURS OF NEAR 32F TEMPS AND LIGHT
FROST. OTHERWISE...JUST A COLD MORNING THAT WILL LIKELY BREAK THE
RECORD LOW AT AUS.

FAST JET STREAM FLOW WILL DROP WEAK DISTURBANCES INTO THE DESERT
SOUTHWEST U.S...THEN SHEAR THEM OUT ACROSS TEXAS. EXPECT THE
STRONGEST ONE THU/FRI TO HAVE ENOUGH CIRCULATION TO ENHANCE RETURN
FLOW AND PRODUCE ISENTROPIC LIFT AND POPS. OTHERWISE...TEMPS WILL
TREND BACK TO NEAR NORMAL BY THE END OF THE WEEK.

RECORD LOWS FOR TUE 10/25
AUS 38 IN 1999
ATT 33 IN 1924
DRT 39 IN 1906
SAT 36 IN 1945

RECORD LOWS FOR WED 10/26
AUS 41 IN 1982
ATT 31 IN 1924
DRT 40 IN 1909
SAT 38 IN 1955

&&

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

04/25

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
539 AM CDT MON OCT 24 2005

TXZ171>173-183>194-202>209-217>225-228-251045-
LLANO-BURNET-WILLIAMSON-VAL VERDE-EDWARDS-REAL-KERR-BANDERA-
GILLESPIE-KENDALL-BLANCO-HAYS-TRAVIS-BASTROP-LEE-KINNEY-UVALDE-
MEDINA-BEXAR-COMAL-GUADALUPE-CALDWELL-FAYETTE-MAVERICK-ZAVALA-
FRIO-ATASCOSA-WILSON-KARNES-GONZALES-DE WITT-LAVACA-DIMMIT-
539 AM CDT MON OCT 24 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...TODAY AND TONIGHT
SHOWERS OVER THE SOUTHERN PART OF SOUTH CENTRAL TEXAS ARE FORECAST
TO MOVE AWAY FROM THE AREA LATER THIS MORNING.  DAYTIME HIGHS
TODAY ARE FORECAST TO BE 15 TO 20 DEGREES COOLER THAN ON SUNDAY.
CLEAR AND COLD CONDITIONS ARE EXPECTED TONIGHT...WITH SOME OF THE
COOLEST OVERNIGHT LOWS SINCE EARLY APRIL OF THIS YEAR. OVERNIGHT
LOWS ARE EXPECTED TO BE IN THE MID 30S OVER THE HILL COUNTRY TO
THE UPPER 30S AND LOW 40S OVER SOUTH CENTRAL TEXAS.  NO HAZARDOUS
WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
INCREASING CLOUDINESS IS EXPECTED LATER THIS WEEK AND THIS
WEEKEND. THERE IS A SLIGHT CHANCE FOR SHOWERS LATE THIS WEEK.
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.