FXUS64 KBMX 151133
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
533 AM CST TUE DEC 15 2009

.UPDATE...FOR 12Z AVIATION.

&&

.SHORT TERM...TODAY AND TONIGHT.

COLD FRONT ACROSS THE NORTHWEST SECTIONS WILL MOVE SOUTHEAST ACROSS 
THE AREA TODAY AND EXIT THE SOUTHEAST SECTIONS EARLY THIS EVENING.  
MODELS INDICATE SEVERAL IMPULSES MOVING FROM SOUTHWEST TO NORTHEAST 
ACROSS THE SOUTHERN SECTIONS.  WILL FORECAST CATEGORICAL POPS ACROSS 
MUCH OF THE SOUTH AND CONTINUE THE FLASH FLOOD WATCH DUE TO  
SATURATED CONDITIONS.  BEST CHANCE OF LOCALLY HEAVY RAINFALL WILL BE 
ACROSS THE SOUTHEAST SECTIONS. POPS WILL BE TAPERED LOWER AS WE 
SHIFT NORTHWARD.  HIGH TEMPERATURES WILL OCCUR THIS MORNING AT MOST 
LOCATIONS...ESPECIALLY ACROSS THE NORTH AND SLOWLY FALL THROUGHOUT 
THE DAY.  WILL CANCEL THE DENSE FOG ADVY AND MENTION SOME PATCHY FOG 
EARLY.  DRIER/COLDER AIR SPREADS SOUTHWARD TONIGHT AND WILL LEAVE 
ANY MENTION OF RAIN OUT OF THE FORECAST.  LOWS TONIGHT MAINLY IN THE 
30S.

.LONG TERM...WEDNESDAY THROUGH MONDAY.

WEDNESDAY/THURSDAY...HIGH PRESSURE BUILDS INTO AND ACROSS THE AREA.
GOOD DEAL OF SUNSHINE EXPECTED EACH DAY WITH AFTERNOON READINGS IN
THE 50S. OVERNIGHT LOWS 25 TO 35.

THURSDAY NIGHT AND FRIDAY...MODELS INDICATE WEAK LOW PRESSURE
DEVELOPING IN THE NORTHERN GULF AND SLOWLY SHIFTING NORTHEAST...
BRUSHING THE SOUTHERN SECTIONS.  WILL INCREASE CLOUDS THURSDAY
NIGHT AND MENTION SLIGHT CHANCE OF SHOWERS ACROSS THE EXTREME SOUTH
ON FRIDAY.  LOWS 25 TO 35.  HIGHS 55 TO 60 NORTH AND 60 TO 65
SOUTH.

SATURDAY THROUGH MONDAY...SECONDARY SURGE OF COLDER AIR WILL SPREAD
SOUTHEAST ACROSS THE AREA ON SATURDAY AS WEAK COLD FRONT MOVES
THROUGH.  A LITTLE MORE MOISTURE INDICATED THIS RUN AND WILL
INCLUDE A SLIGHT CHANCE OF RAIN ON SATURDAY.  OTHERWISE...PASSING
CLOUDS AS FLOW REMAINS FROM THE NORTHWEST.  HIGHS 45 TO 55.
LOWS 25 TO 35.

&&

.AVIATION...12Z TAF DISCUSSION.

SHOWERS CONTINUE TO SKIRT THE SOUTHERN PERIPHERY OF THE CENTRAL 
ALABAMA FORECAST AREA THIS MORNING AS THE BOUNDARY RESPONSIBLE FOR 
THESE SHOWERS HANGS BETWEEN MONTGOMERY AND THE GULF COAST.  THESE 
SHOWERS ARE EXPECTED TO CONTINUE THROUGH MOST OF THE DAY...SLOWLY 
PUSHING TO THE SOUTH AND DRYING UP BY 16/00Z.  THIS MEANS -RA/RA 
WILL BE EXPERIENCED AT TOI THROUGH THIS TIME...AND MGM FOR MOST OF 
THIS TIME.  EITHER WAY...BOTH SITES WILL BE RUNNING IFR CEILINGS 
AND/OR VIS THROUGH AT LEAST 21Z...WITH CONDITIONS GRADUALLY 
IMPROVING AFTER 16/00Z BEHIND THE FROPA.  

FOR THE NORTHERN SITES...THE COLD FRONT HAS ALREADY MOVED THROUGH 
BHM AND TCL...AND WILL MOVE THROUGH EET AND ANB BY 13Z.  THIS WILL 
SWING WINDS AROUND TO THE NORTH AND DIMINISH THE CHANCES OF ANY 
SIGNIFICANT RAINFALL THIS MORNING.  BUT EVEN WITHOUT THE RAIN...LOOK 
FOR LOW CLOUDS THROUGH THE NOON HOUR AND CONDITIONS IMPROVING TO 
VFR...WITH A MIDLEVEL OVC DECK THROUGH 16/05-06Z.  SKIES SHOULD 
CLEAR FROM NORTH TO SOUTH THROUGH THE OVERNIGHT HOURS...THOUGH IT IS 
POSSIBLE THAT MGM AND TOI DO NOT CLEAR OUT UNTIL CLOSE TO DAYBREAK 
ON WEDNESDAY.

NOT EXPECTING ANY SIGNIFICANT WINDS BEHIND THE FRONT...THOUGH SHOULD 
STILL SEE AN 8-12 KT NORTHERLY BREEZE AFTER THE FROPA THROUGH ANY 
GIVEN SITE.

27

&&

.BMX WATCHES/WARNINGS/ADVISORIES...

FLASH FLOOD WATCH FOR..DALLAS...AUTAUGA...LOWNDES...ELMORE...
MONTGOMERY...MACON...BULLOCK...LEE...RUSSELL...PIKE...AND BARBOUR 
COUNTIES UNTIL 6 PM CST TUESDAY.

&&

$$

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