FXUS64 KEWX 022349
AFDEWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
549 PM CST WED DEC 2 2009
.AVIATION...
SATELLITE IMAGERY AND OBS TO THE NORTH AND NORTHWEST CONTINUE
TO INDICATE CIGS NEAR 3 THSD TO 5 THSD BKN TONIGHT. FORECASTS
SHOW THIS LAYER OF CLOUDS MOVING TO THE EAST AFTER 12Z THURSDAY
FOLLOWED BY INCREASING CLOUDS BETWEEN 8 THSD AND 25 THSD FT IN
ADVANCE OF A FAST MOVING WEATHER DISTURBANCE ALOFT. AS THIS
WEATHER SYSTEM MOVES NEAR WEST TEXAS THURSDAY EVENING...INCREASING
CLOUDS FROM 4 THSD TO 8 THSD FT IS EXPECTED. NORTH WINDS AT 10
TO 15 KNOTS WILL DIMINISH TO AROUND 5 TO 10 KNOTS TONIGHT AND]
THEN BECOME NORTH TO NORTHEAST NEAR 10 KNOTS THURSDAY...AND
INCREASE TO 10 TO 15 KNOTS THURSDAY NIGHT...AS ANOTHER WAVE OF
COLD AIR PASSES THROUGH THE REGION.
&&
.PREV DISCUSSION... /ISSUED 401 PM CST WED DEC 2 2009/
DISCUSSION...
COLD AIR ADVECTION WILL CONTINUE TONIGHT INTO FRIDAY AHEAD OF THE
APPROACHING UPPER LEVEL TROUGH AND RESULT IN TEMPERATURES WELL
BELOW NORMAL ACROSS MUCH OF THE AREA. A QUICK LOOK AT THE SURFACE
OBSERVATIONS ACROSS THE CENTRAL AND NORTHERN PLAINS SHOWS 3PM
TEMPERATURES IN THE 20S AND 30S...WITH A FEW SPOTS IN THE UPPER
TEENS. DEWPOINT TEMPERATURES IN THE TEENS ARE COMMON IN THIS
AIRMASS...WHICH WILL BUILD INTO OUR AREA GOING INTO FRIDAY.
THE LARGE TROUGH TAKING SHAPE ACROSS THE NORTHERN PLAINS WILL LIFT
NE OVER THE NEXT 48-72H. AT THE SAME TIME...SHORTWAVE ENERGY WILL
MOVE AROUND THE BASE...ACROSS THE SOUTHERN ROCKIES THURSDAY AND
ACROSS OUR AREA FRIDAY. A COASTAL TROUGH IS FORECAST TO DEEPEN
THURSDAY NIGHT IN RESPONSE TO THE APPROACHING UPPER LEVEL SHORT
WAVE TROUGH. THE FORECAST POSITION AND MAGNITUDE OF THE COASTAL
TROUGH WILL BE A BIG PLAYER IN THE SNOW FORECAST. THERE ARE SOME
DIFFERENCES AMONG THE 12Z MODEL SUITE WITH REGARD TO THE COASTAL
TROUGH...WITH THE 12Z GFS MORE BULLISH ON THE QPF...ESPECIALLY
ACROSS OUR SE COUNTIES. THE 12Z GFS FORECAST SOUNDINGS FOR OUR SE
COUNTIES SHOW CLASSIC SNOW TRACES FRIDAY...SO PRECIP WILL LIKELY
BE ALL SNOW. OUR FORECAST SNOWFALL AMOUNTS ARE GENERALLY A BLEND
OF THE 12Z NAM12 AND GFS40 SNOWFALL AMOUNT OUTPUT...MINUS A
QUARTER TO HALF INCH FOR ANTICIPATED MELTING. WILL PASS ON A
WINTER STORM WATCH FOR NOW GIVEN OUR FORECAST AMOUNTS AND
UNCERTAINTY WITH FORECAST COASTAL TROUGH EVOLUTION...BUT A WATCH
MAY BE NECESSARY WITH LATER MODEL RUNS. FOR NOW...HAVE UPDATED THE
SPECIAL WEATHER STATEMENT AND CREATED WEB GRAPHICS TO HIGHLIGHT
THE SNOW FORECAST. IN ADDITION...A HARD FREEZE IS FORECAST FRIDAY
NIGHT INTO SATURDAY MORNING AND A FREEZE WARNING WILL LIKELY BE
REQUIRED.
THE HIGH AMPLITUDE SYNOPTIC PATTERN CURRENTLY IN PLACE IS FORECAST
TO BE REPLACED WITH A NEAR ZONAL PATTERN ACROSS THE SOUTHERN U.S.
BY 12Z MONDAY. ANOTHER FRONT IS FORECAST TO PUSH THROUGH 12Z
MONDAY...WITH A QUICK TURN-AROUND AND ANOTHER FRONT TUESDAY NIGHT.
TEMPERATURES WILL GENERALLY BE BELOW TO WELL BELOW NORMAL FOR THE
NEXT SEVEN DAYS. WE'RE FORECASTING NEW RECORD LOW MAX TEMPS FRIDAY
FOR THE ENTIRE AREA...AND WILL LIKELY SEE A FEW NEW RECORD LOW
TEMPS ON SATURDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 38 52 34 37 29 / 0 0 10 70 10
AUSTIN BERGSTROM INTL AIRPORT 35 51 34 36 22 / 0 0 10 70 20
NEW BRAUNFELS MUNI AIRPORT 36 53 35 37 24 / 0 0 10 70 20
BURNET MUNI AIRPORT 33 48 32 34 22 / 0 0 10 70 -
DEL RIO INTL AIRPORT 39 55 37 38 29 / 0 0 20 50 -
GEORGETOWN MUNI AIRPORT 33 50 33 36 27 / 0 0 10 70 10
HONDO MUNI AIRPORT 35 56 37 38 23 / 0 0 20 60 -
SAN MARCOS MUNI AIRPORT 36 51 34 37 26 / 0 0 10 70 20
LA GRANGE - FAYETTE REGIONAL 37 51 36 39 27 / 0 0 10 80 30
SAN ANTONIO INTL AIRPORT 38 55 37 38 27 / 0 0 10 70 10
STINSON MUNI AIRPORT 38 54 38 38 26 / 0 0 10 70 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/08/19/11/26
