000
FXUS64 KBMX 181140
AFDBMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
640 AM CDT TUE JUN 18 2013

.DISCUSSION...

A BROAD UPPER-LEVEL TROUGH AND ASSOCIATED FRONT WILL MOVE THROUGH
THE REGION TODAY WITH ANOTHER ROUND OF WIDESPREAD SHOWERS AND
THUNDERSTORMS. THE HIGHEST RAIN CHANCES WILL SHIFT FROM THE
NORTHWEST TO THE SOUTHEAST THROUGH THE MORNING AND INTO THE
AFTERNOON. CANNOT RULE OUT A FEW STRONGER STORMS WITH PERHAPS
THE BEST POTENTIAL ACROSS THE SOUTHEAST HALF OF THE AREA WHERE
TEMPERATURES SHOULD BE THE WARMEST. BY TONIGHT THE WEAKENING FRONT
SHOULD BE SLOWLY MOVING THROUGH THE SOUTHERN AREAS WITH SHOWERS
AND THUNDERSTORMS LIKELY FOR THE OVERNIGHT ACROSS THE SOUTH. WHILE
DRIER AIR IS EXPECTED TO MOVE IN FROM THE NORTH...A SHARP DROP IN
LOW-LEVEL MOISTURE IS NOT ANTICIPATED IN THE WAKE OF THE FRONT AND
HAVE KEPT CHANCE POPS IN FOR WEDNESDAY ACROSS THE FAR SOUTH IN THE
VICINITY OF THE REMNANT FRONTAL BOUNDARY. A SIMILAR SCENARIO IS
EXPECTED FOR THURSDAY AS WELL.

MODELS AGREE THAT AN UPPER-LEVEL WEAKNESS WILL REMAIN OVER THE
REGION DURING THE EXTENDED PERIOD. SOUTHEASTERLY LOW-LEVEL FLOW
WILL BEGIN TO TAKE SHAPE BY FRIDAY AROUND THE WESTERN SIDE OF A
SUBTROPICAL RIDGE. THIS SHOULD LEAD TO INCREASING MOISTURE AND
RAIN CHANCES FOR FRIDAY AND INTO THE WEEKEND AS A SUMMER-LIKE
PATTERN ARRIVES.

87/GRANTHAM


&&

.AVIATION...
12Z TAF DISCUSSION.

TYPICALLY WHEN YOU HAVE FAIRLY WIDESPREAD RAIN OVERNIGHT YOU DO
NOT SEE A REPEAT THAT QUICKLY. HOWEVER TODAY WILL BE A TOUCH
DIFFERENT AS THE RAIN OVERNIGHT WAS ENHANCED BY A VORTICITY MAX
ROTATING THROUGH WELL AHEAD OF A COLD FRONT ALOFT. THIS COLD FRONT
IS REFLECTED AT THE SURFACE AS WELL AND STILL WEST OF AN UOX AND
JAN LINE IN MS. UNTIL THE FRONT WORKS THROUGH WE WILL REMAIN IN
SOUTHWESTERLY FLOW AND RAIN CHANCES REMAIN HIGH. LOOK FOR THE BEST
CHANCES THROUGH 15Z TO BE BETWEEN TAF SITES. AFTER 15Z...LOOK FOR
AN EXPANSION IN COVERAGE AS WE GET THE DIFFERENTIAL HEATING IN
ADDITION TO THE INFLUENCE OF THE FRONT. HIGHEST TIMING CONFIDENCE
IS ACTUALLY IN THE SOUTHEAST...WHERE HEATING WILL INCREASE CHANCES
AFTER 18Z. AREAS NORTH WILL LIKELY SEE OCCASIONAL SHOWERS AND
STORMS THROUGH THE EARLY AFTER BUT TIMING OF THESE REMAIN TRICKY
AND WENT WITH VCTS FOR THE TIME BEING. AFTER 00Z NORTH AND 3Z
SOUTH...TAFS SHOULD SWITCH TO A NORTHERLY FLOW AND CLOUDS WILL BE
SLOW TO CLEAR. WENT A TOUCH SLOWER THAN MODELS IN CLEARING TRENDS
OVERNIGHT. DRIER DURING THE MORNING ON WEDNESDAY ACROSS THE NORTH.

16

&&

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

&&

$$