Area Forecast Discussion
Issued by NWS Austin/San Antonio, TX

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KEWX 270548 AAA
AFDEWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
1148 PM CST FRI DEC 26 2014

.AVIATION.../06Z TAF CYCLE/

MVFR AND IFR CONDITIONS HAVE RETURNED TO KAUS/KSAT/KSSF OVER THE
PAST HOUR AS ANTICIPATED. KDRT REMAINS VFR WITH THE COLD FRONT
LIKELY AN HOUR AWAY AND THIS TIMING SHOULD PRECLUDE STRATUS FROM
REACHING KDRT AS DRIER NW FLOW TAKES OVER. IFR TO LIFR ARE LIKELY
FOR CENTRAL SITES OVERNIGHT THROUGH 14-15Z. VIS RESTRICTIONS WILL
ALSO BE POSSIBLE FOR KSAT/KSSF IN THE 1-2SM RANGE AND SLIGHTLY
HIGHER FOR KAUS 2-4SM. VIS WILL IMPROVE BY 14-15Z BUT -DZ WILL BE
POSSIBLE FOR CENTRAL SITES 13Z-22Z AS COLD FRONT MOVES THROUGH.
KDRT WIND HAS TURNED NW AS OF 06Z BUT FEEL FRONT HAS NOT FULLY
ARRIVED BASED ON RADAR TRENDS FROM KSJT. NORTH WIND SHIFT WILL
OCCUR FOR KAUS 10-11Z AND KSAT/KSSF 12-14Z. WIND BEHIND COLD FRONT
WILL BE 12-18 KT AND GUST TOWARDS 25 KT DURING THE AFTERNOON AND
EVENING HOURS SATURDAY BEFORE SLOWLY CALMING TOWARDS MIDNIGHT.
/ALLEN/

&&

.PREV DISCUSSION... /ISSUED 833 PM CST FRI DEC 26 2014/

UPDATE...
LOOKS LIKE FOR THE MOST PART THE AFTERNOON FORECAST IS ON TRACK.
ONE CHANGE THAT WAS MADE BASED ON HIGH RESOLUTION MODELS AND EVENING
RADAR TRENDS IS TO TAKE OUT MENTION OF PRECIPITATION BEFORE MIDNIGHT.
IN A FEW AREAS ALONG INTERSTATE 35 TEMPERATURE ARE HAVE ALREADY
DROPPED TO NEAR 60 DEGREES. FOR THIS REASON ADJUSTED LOWS
OVERNIGHT DOWN A DEGREE IN THESE SPOTS. BASED ON MODEL SOUNDINGS
HAVE ALSO PUSHED BACK THE MENTION OF THUNDER FOR THE MORNING HOURS
TOMORROW. AN ISOLATED THUNDERSTORM IS NOT OUT OF THE QUESTION
ACROSS OUR FAR EASTERN COUNTIES AND COASTAL PLAINS WITH THE
FRONTAL PASSAGE. HAVE ALSO BUMPED UP WIND GUSTS FOR TOMORROW
AFTERNOON BEHIND THE FRONT BASED ON SOME OF THE SHORT TERM MODELS.
REST OF THE FORECAST APPEARS GOOD WITH FOG EXPECTED TOMORROW
MORNING AHEAD OF THE FRONT AND A CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGHOUT THE DAY.

TREADWAY

PREV DISCUSSION... /ISSUED 257 PM CST FRI DEC 26 2014/

SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
SOUTH WINDS WILL DECREASE THIS EVENING AND LEAVE TEMPERATURES TO
COOL TO SATURATION ACROSS MANY LOCATIONS TONIGHT. AN UPPER TROUGH
CARVING INTO NRN MEXICO WILL ALSO PROVIDE SOME LIFT THAT COULD
RESULT IN SCATTERED MOSTLY LIGHT RAIN SHOWERS. THE BUOYANCY AND
SHIFTING OF THE SURFACE PATTERN SHOULD LIMIT THE FORMATION OF A
SUSTAINED DENSE FOG PATTERN...SO WILL KEEP THE MENTION OF DENSE
FOG POSSIBILITIES CONFINED TO THE HWO. THE FOG KICKER WILL BE A
COLD FRONT NOW EXPECTED TO MOVE THROUGH MOST AREA AFTER DAYBREAK
SATURDAY. THE SLOWER TREND OF THE FRONT MEANS SOME SOUTHERN
COUNTIES COULD HAVE A NICE LATE MORNING WARM-UP BEFORE TEMPERATURES
LEVEL OFF. LIGHT SHOWERS BEHIND THE FRONT AND ISOLATED
THUNDERSTORMS NEAR AND AHEAD OF THE FRONT ARE NOT EXPECTED TO
PRODUCE SIGNIFICANT RAINS...BUT FAR EAST COUNTIES COULD SEE SPOTTY
AMOUNTS OVER 1/2 INCH. A SHEARING OUT UPPER TROUGH STILL LOOMS
JUST TO THE WEST SATURDAY NIGHT...SO LIGHT OVERRUNNING SHOWERS
WILL REMAIN POSSIBLE IN SUNDAY MORNING. NAM MODEL SOUNDINGS
AROUND DRT SUGGEST THE POTENTIAL FOR A FEW FLURRIES...BUT WILL
KEEP OUT OF THE FORECAST FOR NOW.

LONG TERM (SUNDAY THROUGH FRIDAY)...
THE ABOVE MENTIONED UPPER TROUGH AXIS PASSES OVER TX DURING THE
DAY SUNDAY WITH DECREASING RAIN CHANCES AND CLEARING SKIES
ENABLING SOME SUNSHINE AND WARMING OVER WESTERN COUNTIES. DRIER
AIR AND LIGHT WINDS IN THE WAKE OF THE TROUGH WILL ENABLE COOL
MORNING LOWS MOSTLY IN THE 30S FOR MONDAY. AFTER ONE MORE MILD
AFTERNOON MONDAY...A SUSTAINED COLD AND DREARY PATTERN BEGINS WITH
THE NEXT FRONT SET TO ARRIVE EARLY TUESDAY.

A HIGH AMPLITUDE UPPER RIDGE DEVELOPS OVER THE PACIFIC COAST OF
CANADA BY MONDAY AND RESULTS IN A SOUTHWARD SURGE OF ARCTIC AIR.
AIDED BY A BROAD SNOWPACK ALREADY DEVELOPING OVER THE HIGH PLAINS
NEAR THE CENTRAL ROCKIES...THE TUESDAY FRONT SHOULD BRING A THICK
AND DENSE LAYER OF COLD AIR AND ENTER AN OVERRUNNING PATTERN
ALOFT THAT IS ENHANCED BY AN UPPER LOW DIGGING OVER THE SWRN US.
WILL KEEP SLIGHTLY COOLER THAN MODEL CONSENSUS ON TEMPS FOR
TUESDAY INTO EARLY WEDNESDAY AND FALL INTO ALIGNMENT WITH MODEL
TEMPS AFTERWARDS. THE OVERRUNNING PATTERN AND TEMPERATURES NEAR OR
BELOW FREEZING MEANS LIGHT WINTER PRECIPITATION IS POSSIBLE...BUT
LOW PROBABILITIES AND VERY LIGHT AMOUNTS ARE EXPECTED THROUGH
WEDNESDAY.

MODEL TEMPERATURE TRENDS ARE FLAT FOR WEDNESDAY NIGHT...WITH NEAR
FREEZING CONDITIONS POSSIBLE FOR NORTHERN COUNTIES. THE TRENDS GFS
AND PARALLEL RUN OF HIGHER RESOLUTION OUTPUT SHOWS INCREASING QPF
POTENTIAL FOR THURSDAY MORNING...WHICH WOULD BE A CONCERN FOR JAN
1 SHOULD FREEZING TEMPS HANG AROUND. WITH THE ASSOCIATED LIFT
BEING MOSTLY ISENTROPIC...THE CURRENT THINKING IS THAT THE
INCREASING PRECIP MODIFIES THE AIR MASS TO MOVE SURFACE TEMPS ABOVE
FREEZING. THIS ASSUMES THE MODEL TRACK OF THE UPPER LOW DOES NOT
DEVIATE MUCH FROM THE PREFERRED 12Z GFS ENSEMBLE MEAN
FORECAST...WHICH IS A SHALLOWER COMPROMISE BETWEEN THE GFS AND
ECMWF. NEXT SATURDAY HAS A CHANCE TO BE FAIR AND MILD IN THE WAKE
OF THE PASSING UPPER LOW...BUT THE HIGH AMPLITUDE PATTERN
PERSISTS AND SUGGEST MORE COLDER THAN NORMAL PERIODS ARE ON THE
WAY FOR EARLY JANUARY.

&&

.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY              56  56  38  54  36 /  20  40  20  10  10
AUSTIN BERGSTROM INTL AIRPORT  54  57  38  53  31 /  20  40  20  10  10
NEW BRAUNFELS MUNI AIRPORT     57  58  40  55  35 /  20  50  20  10  10
BURNET MUNI AIRPORT            50  50  35  52  34 /  20  30  20  10  10
DEL RIO INTL AIRPORT           49  59  39  60  37 /  10  10  20  -   -
GEORGETOWN MUNI AIRPORT        53  53  37  51  34 /  20  40  20  10  10
HONDO MUNI AIRPORT             54  57  37  58  33 /  10  30  20  10  10
SAN MARCOS MUNI AIRPORT        57  58  38  53  33 /  20  50  20  10  10
LA GRANGE - FAYETTE REGIONAL   61  63  41  52  35 /  30  60  30  20  10
SAN ANTONIO INTL AIRPORT       56  57  40  56  37 /  20  40  20  10  10
STINSON MUNI AIRPORT           57  60  41  57  36 /  20  40  20  10  10

&&

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

$$

MESOSCALE/AVIATION...15
SYNOPTIC/GRIDS...12





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.