000 
FXUS64 KBMX 201142
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
635 AM CDT THU SEP 20 2007

.UPDATE...FOR AVIATION DISCUSSION.

&&

.SHORT TERM...TODAY AND TONIGHT.

DEVELOPING UPPER LOW OVER THE NORTHEAST GULF WILL CONTINUE TO DEEPEN
AND SLOWLY WORK WESTWARD TODAY AND TONIGHT.  EASTERLY FLOW
WILL BRING MOISTURE INTO THE AREA MAINLY IN THE FORM OF CLOUDS LATER
TODAY AND ESPECIALLY TONIGHT.  NORTHERN HALF OF THE AREA WILL SEE A
GOOD AMOUNT OF SUNSHINE TODAY AS CLOUDS SPREAD INTO THE SOUTHERN
SECTIONS.  HIGHS TODAY IN THE MIDDLE TO UPPER 80S.  FOR TONIGHT WILL
CONTINUE THE TREND OF INCREASING CLOUDS AND ALSO MENTION A SLIGHT
CHANCE OF SHOWERS LATE ACROSS THE EXTREME SOUTHEAST SECTIONS.
OVERNIGHT LOWS IN THE 60S.

KSL


.LONG TERM...FRIDAY THROUGH WEDNESDAY.

AS THE UPPER LEVEL LOW CONTINUES TO TRACK ACROSS THE NORTHERN GULF
OF MEXICO...MOISTURE WILL GRADUALLY INCREASE ACROSS THE AREA. THERE
ARE STILL MODEL DIFFERENCES WITH THE TIMING OF THE SYSTEM AS IT
MOVES WESTWARD...AND EXACTLY HOW FAR NORTHWARD ANY RAIN ASSOCIATED
WITH THE FEATURE WILL BE. THE BEST CHANCE FOR SHOWERS WILL REMAIN
ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA FRIDAY AND
SATURDAY. THE LOW SHIFTS WEST OF THE ALABAMA COAST SATURDAY AS IT
BECOMES LESS ORGANIZED AT UPPER LEVELS.

THE SYSTEM MAKES IT WAY UP THE MISSISSIPPI RIVER VALLEY...ON THE
PERIPHERY OF THE UPPER LEVEL HIGH...AND MERGES WITH THE LONGWAVE
TROUGH PATTERN LATE MONDAY. AS THE LOW MOVES NORTHWARD...ANOTHER
SURGE OF MOISTURE WILL MOVE INTO CENTRAL ALABAMA. THIS WILL AID IN
THE DEVELOPMENT OF RAIN SHOWERS...AND DIURNAL THUNDERSTORM
ACTIVITY DURING THE EARLY PART OF NEXT WEEK. THE UPPER LEVEL RIDGE
BUILDS BACK ACROSS THE AREA SUNDAY AND MONDAY...ALLOWING HIGHS TO
RETURN TO NEAR 90 DEGREES IN MOST LOCATIONS.

MODELS INDICATE A WEAKENING UPPER LEVEL SHORT WAVE MOVING ACROSS THE
MIDWEST WILL PUSH THE TAIL END OF A COLD FRONT THROUGH THE REGION
LATE TUESDAY. WITH MORE MOISTURE IN PLACE ACROSS THE AREA...AND THE
POSSIBLE FRONTAL BOUNDARY...KEPT CHANCE POPS IN FOR WEDNESDAY AND
WEDNESDAY NIGHT.

14

&&

.AVIATION...12Z TAF DISCUSSION.

UNRESTRICTED CEILINGS AND VISIBILITIES FOR THE NORTHERN TAF SITES
THROUGH THE NEXT 24 HOURS.  SOME MID AND HIGH CLOUDS WILL BEGIN TO
WORK INTO THE SOUTHERN SITES DURING THE AFTERNOON AND TONIGHT.
LOW CLOUDS WILL DEVELOP AFTER 08Z AT MGM AND TOI WITH CEILINGS 1000
TO 2000 FEET.  NORTHEAST WINDS 10 TO 15 MPH CAN BE EXPECTED FROM 18Z
THROUGH 00Z AT ALL SITES WITH SOME GUSTS TO 20 MPH AT MGM AND TOI.

KSL

&&

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

&&

$$
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