000 
FXUS64 KBMX 020551
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1151 PM CST SUN DEC 1 2013

.UPDATE...
FOR 06Z AVIATION.

&&

.DISCUSSION...

SEEING LIGHT RAIN SHOWERS ACROSS THE NORTHWEST THIS EVENING AS A SHORTWAVE
APPROACHES THE AREA FROM THE WEST. RAIN COVERAGE SHOULD EXPAND AS
THE SHORTWAVE CROSSES CENTRAL ALABAMA FAIRLY QUICKLY OVERNIGHT.
MODELS NOT IN GREAT AGREEMENT ON HOW RAIN TRANSLATES ACROSS THE
AREA...AND TO WHAT EXTENT IT OVERCOMES DRIER AIR IN THE LOWER
LEVELS ACROSS THE EAST. THERE IS GOOD AGREEMENT THAT THE BEST LIFT
WILL PUSH EAST OF THE AREA TOMORROW MORNING.

HAVE ADJUSTED POP/WX GRIDS FOR OVERNIGHT AND TOMORROW TO REFLECT
THE CHANGE IN TIMING. BEST CHANCES REMAIN ACROSS THE NORTH...WITH
COVERAGE DIMINISHING THROUGH THE MORNING HOURS TOMORROW. TEMPERATURES
ARE IN LINE...AND SHOULD REMAIN STEADY ACROSS MOST OF THE AREA FOR
THE REMAINDER OF THE NIGHT. WITH LESS CLOUD COVER AND RAIN ACROSS
THE EAST...TEMPS WILL FALL INTO THE LOW TO MID 4OS. UPPER 40S TO
LOWER 50S EXPECTED ELSEWHERE.

14


&&

.AVIATION...
06Z TAF DISCUSSION.

THE SAME GENERAL SCENARIO REMAINS AS MENTIONED IN PREVIOUS
DISCUSSION. A SHORT WAVE TROUGH MOVES OVER CENTRAL ALABAMA AND
PROVIDES PLENTY OF UPWARD MOTION. THE INGREDIENT THAT IS LACKING
IS THE OVERALL MOISTURE CONTENT. THE MAIN CHANGE THIS TAF CYCLE
WILL BE TO MENTION SOME POSSIBLE LOWERING OF THE CEILINGS INTO IFR
FRO BHM/ANB AROUND DAYBREAK. THESE ARE THE AREAS WERE THE BEST
CHANCE OF PRECIP MAKING IT TO THE GROUND ARE. OTHERWISE...HAVE THE
NORTHERN TERMINALS DECREASING TO MVFR CEILINGS AND LIGHT RAIN IN
THE NEXT FEW HOURS. THESE CEILINGS SHOULD HOLD THROUGH THE PERIOD.
THE SOUTHERN TERMINALS ARE LESS AFFECTED BY THE UPWARD MOTION AND
OVERALL VIRGA/RAIN. THEREFORE...CEILINGS WILL LOWER BUT ONLY
030-035 AND THEN HOLD THE REST OF THE FORECAST. WE WILL MONITOR
HOW THIS LIGHT RAIN SHIELD SETS UP IN THE NEXT SEVERAL HOURS...AND
THE HEAVIER RAIN...IF ANY...SHOULD LOWER CEILINGS THERE.
SMALL PATCHES OF LIGHT RAIN MAY EXIST AFTER 20Z MAINLY NORTH...BUT
CONFIDENCE WAS NOT HIGH ENOUGH FOR MENTION AT THIS TIME.

75

&&

.PREV DISCUSSION...
/ISSUED 232 PM CST SUN DEC 1 2013/

PLEASANT DAY WITH HIGHS IN THE MID 50S TO MID 60S THIS AFTERNOON.
CLOUDY SKIES AHEAD OF AN APPROACHING SHORTWAVE THAT IS GOING TO
TRY TO PROVIDE ENOUGH LIFT TO SQUEEZE OUT A FEW SHOWERS TONIGHT
AND MONDAY. THE AIR IS STILL PRETTY DRY SO THINK RAINFALL AMOUNTS
WILL BE ON THE LIGHT SIDE BUT A DECENT COVERAGE ACROSS THE
NORTHERN TWO-THIRDS OF THE CWA IS POSSIBLE. NOT MUCH WITH THIS
AROUND MGM OR TOI.

THE SHORTWAVE LIFTS OUT MONDAY BUT THEN WE ARE LEFT IN A WEAK
ISENTROPIC LIFTING PATTERN THAT WILL ALLOW FOR SOME PATCHY LIGHT
RAIN OR DRIZZLE DURING THE MIDDLE OF THE WEEK. TEMPERATURES WILL
ALSO BE ALLOWED TO WARM UP WITH MANY LOCATIONS REACHING THE 70S ON
WEDNESDAY AND THURSDAY. 

THURSDAY IS ALSO A TRANSITION DAY INTO A MUCH WETTER PATTERN THAT
COULD LAST THROUGH THE WEEKEND. UPPER RIDGING IN THE GULF AND
SIGNIFICANT TROUGHING IN THE WESTERN CONUS WILL PUT US UNDER
PROLONGED SOUTHWESTERLY FLOW. SEVERAL IMPULSES IN THE PATTERN WILL
BRING NUMEROUS ROUNDS OF SHOWERS AND POSSIBLY A FEW THUNDERSTORMS
TO THE DEEP SOUTH. A COUPLE OF WEAK SURFACE LOWS COULD SPIN UP AND
BRING SOME LOCALLY HEAVY RAINFALL TO AREAS CLOSEST TO THE SURFACE
FRONT. THE BEST LOCATION FOR THIS IS CURRENTLY ALONG AND NORTH OF
I-59. LOOK FOR THE POSSIBILITY OF SOME ICY CONDITIONS NORTH OF
THE FRONT AND WILL HAVE TO CLOSELY WATCH WHERE THIS BOUNDARY SETS
UP AS SOME OF OUR NORTHWESTERN COUNTIES ARE CLOSE TO POTENTIAL
FREEZING RAIN. AT THIS POINT...I THINK IT REMAINS JUST OUTSIDE OF
OUR AREA BUT ITS CLOSE. WILL NOT MENTION ANYTHING IN THE HWO AT
THIS TIME. EXPECT SOME RAIN TO BE AROUND THE AREA THROUGH AT LEAST
SUNDAY AND POSSIBLY LONGER.

88

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     46  57  48  63  53 /  60  50  20  30  20 
ANNISTON    46  58  49  66  56 /  50  40  20  30  20 
BIRMINGHAM  49  60  52  67  58 /  60  50  20  30  20 
TUSCALOOSA  50  63  53  69  58 /  50  50  20  30  20 
CALERA      48  61  51  67  57 /  40  50  20  30  20 
AUBURN      44  62  51  66  56 /  20  10  20  30  10 
MONTGOMERY  46  67  51  73  57 /  20  10  20  30  10 
TROY        44  68  51  73  57 /  10  10  20  30  10 

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
NONE. 

&&

$$