Hail and Damaging Wind in Texas, December 23 to 24, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
853 PM CST WED DEC 23 2009

.UPDATE...
THE LEADING EDGE OF AN UPPER LEVEL SHORT WAVE AND ATTENDANT COLD
FRONT WERE ENTERING CENTRAL PORTIONS OF THE HILL COUNTRY TO THE
MIDDLE RIO GRANDE PLAINS AT MID EVENING. SCATTERED SHOWERS
ACCOMPANIED THE SYSTEM AS THE UPPER LEVEL WINDS WERE SUBSIDENT AND
LIMITING INTENSITIES. SURFACE WINDS WERE NORTHWEST BEHIND THE
FRONT WITH SPEEDS AVERAGING 15 TO 20 MPH WITH GUSTS TO AROUND 30
MPH. THE ENTIRE SYSTEM WAS MOVING EAST AT 40 MPH WITH THE BACK EDGE
(CLEARING AXIS) EXPECTED TO MOVE INTO FAR WESTERN PORTIONS OF THE
CWA AROUND MIDNIGHT...AND EXITING REGION AROUND DAWN. THERE
REMAINS A SLIGHT RISK OF SEVERE THUNDERSTORMS GENERALLY ALONG AND
EAST OF THE I-35 CORRIDOR LATE THIS EVENING INTO THE OVERNIGHT
HOURS WHEN THE SYSTEM INTERACTS WITH THE LOW LEVEL JET AND RICHER
GULF MOISTURE. CHANGED CLOUD GRIDS ON THE UPDATE..OTHERWISE
CURRENT FORECAST LOOKS FINE AT PRESENT.

&&

.PREV DISCUSSION... /ISSUED 529 PM CST WED DEC 23 2009/

AVIATION...
A STRONG COLD FRONT IN WEST TX WILL BLAST SEWD INTO THE WESTERN
HILL COUNTRY AND RIO GRANDE PLAINS THIS EVENING INCLUDING KDRT
NEAR 03Z. SCT SHRA WILL ACCOMPANY THE COLD FRONT IN THE WEST WITH
ISOLATED SHRA/TSRA ACROSS THE COASTAL PLAINS THIS EVENING. OTHERWISE
VFR CONDITIONS WILL BECOME TEMPORARILY MVFR CIGS BEHIND THE
FRONT. GUSTY NW WINDS OF 15-25 KNOTS BEHIND THE CDFNT AND SLY 5 TO
15 KNOTS AHEAD. BY 05Z SCT SHRA/TSRA COULD BRIEFLY BECOME SEVERE
GENERALLY EAST OF 281 UNTIL ABOUT 08Z. THE SCT SHRA/TSRA WILL MOVE
EAST OF THE AREA BY 10Z WITH PATCHES OF -RA CONTINUING. CONDITIONS
BECOMING VFR AFTER 24/12Z WITH GUSTY NW WINDS OF 20 TO 30 KNOTS
THRU MUCH OF THE DAY THURSDAY.

PREV DISCUSSION... /ISSUED 344 PM CST WED DEC 23 2009/

DISCUSSION...
THE UPPER LOW AND ATTENDANT COLD FRONT WILL CONTINUE TO APPROACH
THE REGION THIS EVENING. SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO BUILD IN ADVANCE OF THE SYSTEM AND CONTINUE OVERNIGHT. THE COLD
FRONT WILL REACH THE I-35 CORRIDOR BY ABOUT MIDNIGHT AND SWEEP TO
THE COAST BY SUNRISE. THERE IS A SLIGHT RISK FOR SOME OF THE
THUNDERSTORMS TO BECOME SEVERE MAINLY ALONG AND EAST OF A LINE
FROM LLANO TO SAN ANTONIO TO VICTORIA. HAIL IS THE PRIMARY
THREAT BUT DAMAGING STRAIGHT-LINE WINDS ARE ALSO POSSIBLE. THE
BULK OF THE ACTIVITY WILL SWEEP TO THE EAST BY DAWN WITH ONLY A
FEW LINGERING STORMS EXPECTED ACROSS THE FAR EASTERN CWA.

STRONG NORTHWEST WINDS WILL FILTER IN BEHIND THE FRONT OVERNIGHT
THROUGH THURSDAY EVENING. A WIND ADVISORY IS IN EFFECT FROM 9 AM
UNTIL 6 PM FOR THE EASTERN TWO-THIRDS OF THE REGION. COLD AIR
ADVECTION THROUGHOUT THE DAY WILL KEEP HIGH TEMPERATURES LIMITED
TO NEAR 50 ACROSS THE NORTHERN HALF OF THE CWA TO LOWER 60S ACROSS
THE RIO GRANDE VALLEY. CLEARING SKIES...DECREASING WINDS...AND
CONTINUING CAA WILL ALLOW TEMPERATURES TO PLUMMET TO THE FREEZING
MARK CHRISTMAS MORNING.

THE UPPER LOW WILL EJECT TO THE NORTHEAST AND WREAK HAVOC ON THE
MIDWESTERN STATES OVER THE HOLIDAY WEEKEND. THIS POTENT SYSTEM
WILL KEEP HIGH TEMPERATURES ACROSS OUR AREA LIMITED TO THE 50S
WITH FREEZING LOWS AGAIN SATURDAY AND SUNDAY WITH NO PRECIPITATION
EXPECTED. RAIN CHANCES WILL RE-ENTER THE FORECAST EARLY NEXT WEEK
CREATING ANOTHER SERIES OF OVERCAST...CHILLY...AND DAMP DAYS ON
MONDAY AND TUESDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              47  53  31  52  33 /  80  -    0  -   -
AUSTIN BERGSTROM INTL AIRPORT  45  52  30  52  28 /  80  -    0  -   -
NEW BRAUNFELS MUNI AIRPORT     46  57  32  54  30 /  70  -    0  -   -
BURNET MUNI AIRPORT            41  49  29  48  27 /  80  -    0  -   -
DEL RIO INTL AIRPORT           45  62  33  54  33 /  30   0   0   0   0
GEORGETOWN MUNI AIRPORT        46  50  29  49  30 /  80  -    0  -   -
HONDO MUNI AIRPORT             44  61  30  54  29 /  50   0   0  -   -
SAN MARCOS MUNI AIRPORT        49  54  29  53  30 /  80  -    0  -   -
LA GRANGE - FAYETTE REGIONAL   51  56  31  52  31 /  80  10  -   -   10
SAN ANTONIO INTL AIRPORT       48  58  31  55  33 /  60   0   0  -   -
STINSON MUNI AIRPORT           49  60  32  55  33 /  60   0   0  -   -

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 9 AM TO 6 PM CST THURSDAY FOR THE FOLLOWING
COUNTIES: ATASCOSA...BANDERA...BASTROP...BEXAR...BLANCO...BURNET...
CALDWELL...COMAL...DE WITT...FAYETTE...FRIO...GILLESPIE...
GONZALES...GUADALUPE...HAYS...KARNES...KENDALL...KERR...LAVACA...
LEE...LLANO...MEDINA...TRAVIS...WILLIAMSON...WILSON.

&&

02/01

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
315 PM CST WED DEC 23 2009

TXZ171>173-183>194-202>209-217>225-228-241200-
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-
315 PM CST WED DEC 23 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL TEXAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

A DEVELOPING STORM SYSTEM WILL PUSH A COLD FRONT THROUGH SOUTH
CENTRAL TEXAS TONIGHT...WITH SHOWERS AND THUNDERSTORMS FORECAST TO
DEVELOP ALONG AND IMMEDIATELY BEHIND THE FRONT. SOME STORMS MAY
BECOME SEVERE ALONG AND NORTH OF INTERSTATE 10 IN THE HILL COUNTRY
...AND ALONG AND EAST OF THE I-35 CORRIDOR. THE PRIMARY THREAT
WILL BE LARGE HAIL...ALTHOUGH WIND GUSTS TO 60 MPH CAN NOT BE
RULED OUT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

A WIND ADVISORY IS IN EFFECT THURSDAY FOR MUCH OF THE AREA...WITH
NORTHWEST WINDS OF 20 TO 30 MPH EXPECTED. WIND GUSTS WILL
OCCASIONALLY REACH UP TO BETWEEN 35 AND 40 MPH ON THURSDAY. IN
ADDITION...ELEVATED FIRE WEATHER CONDITIONS ARE FORECAST OVER THE
RIO GRANDE VALLEY AND PLAINS THURSDAY.

OTHERWISE...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TONIGHT.