FXUS64 KBMX 160417
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
1000 PM CST TUE DEC 15 2009

.UPDATE...FOR EVENING WEATHER.

&&

.DISCUSSION...

AFTERNOON FORECAST PACKAGE LOOKS TO BE ON TRACK AS TEMPERATURE AND 
DEWPOINTS CONTINUE TO FALL BEHIND THE COLD FRONTAL PASSAGE FROM 
EARLIER TODAY.  CENTRAL ALABAMA WILL BE LEFT WITH SOME DECENT 
COVERAGE OF LOW TO MID CLOUDS IN THE POSTFRONTAL ENVIRONMENT.  THAT 
MAY KEEP TEMPS UP JUST A TAD AS THE BATTLE BETWEEN RADIATIONAL 
COOLING AND ADVECTION COOLING BEGINS TO WAGE ACROSS THE AREA.  SO 
FAR...THE ADVECTION COOLING IS TAKING HOLD...SO HAVE DROPPED TEMPS 
JUST A FEW DEGREES OVER THE REMAINDER OF THE OVERNIGHT.  CLOUDS WILL 
LIKELY BEGIN TO CLEAR THROUGH THE DAY TOMORROW...LEAVING US WITH A 
COOL NORTH WIND AND MUCH COLDER AFTERNOON TEMPS.  UPDATES ARE OUT.  

17/KLAWS

&&

.AVIATION...00Z TAF DISCUSSION.

COLD FRONT BASICALLY JUST SOUTH OF TOI RIGHT NOW. CEILINGS HAVE 
IMPROVED SOMEWHAT BEHIND THE FRONT. CONTINUED TO DELAY CLOUD 
CLEARING THROUGHOUT THE NIGHT NOW. MODELS HAVE NO CLUE ON THE 
CURRENT COLD AIR ADVECTION CLOUDS. SO CONFIDENCE IS REALLY LOW ON 
THIS SET OF TAFS AS GUIDANCE IS REALLY NOT USEFUL AS THEY CLEAR THE 
AREA OUT IN 3 TO 6 HOURS. 

OVERALL WILL SEE A BRIEF WINDOW OF MARGINAL MVFR TO VFR CEILINGS FOR 
THE NEXT SEVERAL HOURS...BEFORE CEILING DROP BACK TO MVFR AREA WIDE. 
LOOKING AT SAT...THE LOW CEILINGS STRETCH AS FAR WEST AS NORTHERN 
LOUISIANA THROUGH THE TENNESSEE VALLEY. THIS MASS HAS NOT REALLY 
MOVED MUCH OVER THE PAST FEW HOURS. BASED ON THE POOR MODEL 
PERFORMANCE HAS KEPT MVFR CEILINGS IN THROUGH 12Z NORTH AND 14Z 
SOUTH. IF WE ACTUALLY BEGIN TO SEE SOME BREAKS IN THE CLOUDS AS THE 
DRIER AIRMASS THAT IS PROGGED TO WORK IN AFTER 3Z...THEN AMENDMENTS 
WILL BE DONE...OTHERWISE EXPECT ANOTHER SOCKED IN NIGHT WITH LOW 
CLOUDS...AND A SLOW CLEARING DURING THE MORNING. WILL LIKELY 
CONTINUE TO SEE A HIGH BKN DECK IN THE SOUTH THROUGH THE END OF THE 
TAF PERIOD. 

&&

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

&&

$$