FXUS64 KBMX 050005 AAA
AFDBMX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BIRMINGHAM AL
605 PM CST FRI DEC 4 2009
.UPDATE...FOR AVIATION.
&&
.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT.
/PREVIOUS DISCUSSION: 314 PM CST FRI DEC 4 2009/
THE POTENTIAL FOR AN EARLY SEASON SNOW HAS INCREASED SOMEWHAT OVER
THE PAST 12 HRS. WE ARE CONTINUING TO WATCH A BROAD UPPER TROUGH
OVER THE CENTRAL CONUS SHIFT EASTWARD THIS AFTERNOON. ITS BRINGING
COLDER AIR WITH IT AND IS GENERATING A WEAK SURFACE LOW IN THE
NORTH CENTRAL GULF THAT WILL SPREAD MOISTURE NORTHWARD THROUGH THE
OVERNIGHT HOURS.
MODELS HAVE BEEN INCONSISTENT ON THE AMOUNT OF PRECIPITATION THAT
WILL BE AVAILABLE AS THE UPPER SYSTEM SHIFTS EASTWARD AND THROUGH
THE AREA OVERNIGHT. HOWEVER, THE 12Z RUNS OF THE NAM AND GFS WERE
IN CLOSE ENOUGH AGREEMENT TO INCREASE CONFIDENCE IN A LOW
ACCUMULATION SNOW EVENT FOR PARTS OF THE AREA.
SNOWFALL IS EXPECTED TO ENTER THE SOUTHWESTERN COUNTIES AROUND
MIDNIGHT AND THEN QUICKLY SPREAD NORTHEASTWARD WITH MUCH OF
CENTRAL ALABAMA SEEING LIGHT SNOW BETWEEN 2 AND 5 AM SATURDAY
MORNING. MODEL QPF AMOUNTS INCREASED THIS MORNING WITH SUGGESTIVE
TOTALS OF UP TO ONE INCH A POSSIBILITY FOR AN AREA THAT ROUGHLY
INCLUDES SUMTER TO CHILTON TO CHEROKEE. A WINTER WEATHER ADVISORY
HAS BEEN ISSUED THIS AFTERNOON FOR COUNTIES SURROUNDING THIS AREA
AND WILL COVER A TIME PERIOD FROM 11 PM THROUGH 6 AM. AREAS SOUTH
OF THE ADVISORY, INCLUDING THE I-85 CORRIDOR AND POINTS SOUTH, MAY
SEE A LITTLE SNOW BUT MOSTLY RAIN AND SHOULD NOT HAVE ANY
SIGNIFICANT ACCUMULATIONS. AREAS IN THE NORTHWEST, INCLUDING
BIRMINGHAM...TUSCALOOSA AND HALEYVILLE, WILL BE COLD ENOUGH FOR
SNOW BUT WILL HAVE TOO LITTLE MOISTURE TO WORK WITH FOR ADVISORY
CRITERIA TO BE MET.
THIS IS EXPECTED TO BE A VERY QUICK MOVING SYSTEM WITH SOME
CLEARING ACTUALLY DEVELOPING FROM WEST TO EAST IN THE AFTERNOON.
SO ANY SNOWFALL THAT DOES DEVELOP WILL QUICKLY MELT AS
TEMPERATURES RISE INTO THE 40S SATURDAY AFTERNOON.
HIGH PRESSURE MOVES OVER THE DEEP SOUTH SATURDAY NIGHT.
TEMPERATURES WILL AVERAGE IN THE MIDDLE 20S FOR MOST LOCATIONS
WITH SOME LOWER 20S POSSIBLE IN THE NORMALLY COLDER SPOTS. HIGH
PRESSURE REMAINS OVER THE AREA SUNDAY WITH HIGHS IN THE 50S AND
LOWS SUNDAY NIGHT IN THE 30S.
.LONG TERM...MONDAY THROUGH FRIDAY.
A SERIES OF SHORTWAVES WILL INFLUENCE THE WEATHER DURING THE WEAK.
NONE OF WHICH APPEAR STRONG AT THIS POINT BUT SOME SHOWERS WILL BE
POSSIBLE FROM MONDAY THROUGH TUESDAY NIGHT AND AGAIN ON FRIDAY.
TEMPERATURES WILL BE SEASONABLE AND WARM ENOUGH TO ELIMINATE ANY
ADDITIONAL WINTER WEATHER CHANCES.
&&
.AVIATION...00Z TAF DISCUSSION.
MID LEVEL CLOUDINESS TO START OUT THEN MVFR CIGS TO INVADE FROM THE
SW AS OUR WINTER WX SYSTEM MOVES INTO C AL. LATE TONIGHT WILL HAVE A
SMALL WINDOW FOR RAIN TO CHANGE OVER TO FREEZING PRECIP. ALOFT
SHOULD BE COLD ENOUGH THAT IF/WHEN WE CHANGE OVER AT TERMINAL SHOULD
BE -SN. CLOUDS ARE EXPECTED TO LIFT AND BEGIN TO CLEAR SOME DURING
THE DAY AS SYSTEM MOVE NE OUT OF C AL.
08
&&
.PRELIMINARY POINT TEMPS/POPS...
GADSDEN 49 31 41 21 49 / 10 70 20 0 0
ANNISTON 50 33 43 24 51 / 10 80 20 0 0
BIRMINGHAM 49 31 43 26 51 / 10 70 10 0 0
TUSCALOOSA 51 29 46 25 51 / 10 60 0 0 10
CALERA 50 33 44 28 52 / 10 70 10 0 0
AUBURN 50 34 43 28 50 / 10 100 10 0 0
MONTGOMERY 50 35 46 25 53 / 10 90 10 0 0
TROY 52 34 49 24 54 / 0 100 10 0 0
&&
.BMX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 11 PM TONIGHT TO 6 AM SATURDAY FOR THE
FOLLOWING COUNTIES...SUMTER-GREENE-HALE-MARENGO-PERRY-DALLAS-BIBB-
CHILTON-AUTAUGA-ELMORE-COOSA-SHELBY-TALLADEGA-CLAY-TALLAPOOSA-
RANDOLPH-CLEBURNE-CALHOUN-ST CLAIR-ETOWAH-CHEROKEE.
&&
$$
88/08
