FXUS62 KMFL 111927
AFDMFL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
227 PM EST FRI DEC 11 2009

.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...FRONTAL BOUNDARY
ACROSS THE LOCAL AREA WILL BEGIN TO MOVE NORTH TONIGHT.
HOWEVER...THE MOVEMENT WILL BE RATHER SLOW AS IT WILL HAVE TO WORK
AGAINST THE LOW LEVEL HIGH OVER THE SE U.S. DECIDED TO KEEP HIGH
SCT POPS THROUGH TONIGHT AND EVEN LIKELY POPS FOR SATURDAY DUE TO
THE SLOW MOVEMENT AND INCREASED LOW LEVEL CONVERGENCE CLOSE TO THE
BOUNDARY. GFS...HOWEVER...GOES WILD WITH RATHER HIGH POPS, BUT
BELIEVE THERE IS A CONVECTIVE FEEDBACK PROBLEM WITH THE MODEL AS
IT DEVELOPS SEVERAL "BULL-EYES" OF HEAVY PRECIP ACROSS THE AREA
THROUGH THIS PERIOD. WL INDICATE A SLIGHT CHANCE OF TSTMS ACROSS
ERN HALF OF SOUTH FLORIDA TONIGHT AND THE EARLY HOURS OF SATURDAY
BUT CONFIDENCE IS LOW AND WL EXPECT MOSTLY SHOWER ACTIVITY.

&&

.LONG TERM...SUNDAY THROUGH TUESDAY...SFC HIGH OVER SE U.S. WILL
QUICKLY MOVE EAST SATURDAY NIGHT AS A SFC LOW DEVELOPS OVER THE
NRN GULF OF MEX AND MOVE NORTHEAST. THIS LOW WILL HELP TO LIFT THE
FRONT WELL NORTH OF THE LOCAL AREA BY SUNDAY WHILE A DEEP LAYER
RIDGE BUILDS FROM SOUTH TO NORTH. THIS WILL HELP TO KEEP VERY LOW
CHANCES FOR RAIN. THERE WERE SPECULATIONS OF RATHER HIGH MAX
AFTERNOON TEMPS DURING THIS PERIOD...HOWEVER, LATEST RUN OF BOTH
GFS AND ECMWF NOW BUILD THE ATLANTIC RIDGE WESTWARD RESULTING IN A
MAINLY SOUTHEAST LOW LEVEL FLOW. THIS WILL LIKELY HELP TO MODERATE
TEMPERATURES ON THE EAST COAST AND KEEP THEM FROM REACHING NEAR
RECORD VALUES. LIKEWISE...SEA BREEZES ON THE WEST COAST COULD HAVE
THE SAME EFFECT.  

.WEDNESDAY THROUGH FRIDAY...LONG RANGE FORECAST MODELS PERSIST IN
DEEPENING A LONG WAVE TROUGH OVER THE ERN HALF OF THE COUNTRY AND
DEVELOPING ANOTHER FRONTAL SYSTEM AS A RESULT. THE FRONT IS
EXPECTED TO MOVE SOUTH ACROSS THE PENINSULA POSSIBLY REACHING LAKE
OKEECHOBEE REGION WED EVENING. HOWEVER...AS IT HAS BEEN THE CASE
MANY TIMES THIS SEASON...MDLS DO NOT SHOW MUCH OF A UPPER LEVEL
SUPPORT AS THE FRONT GETS TO S. FLORIDA AND STALL THE SYSTEM
PRECISELY OVER THE LOCAL AREA BRINGING A SLIGHT CHANCE TO A CHANCE
OF PRECIP DURING THIS PERIOD. 

.MARINE...NE WINDS ARE EXPECTED TO INCREASE TO ABOVE 20 KTS THIS
EVENING AND THIS WILL RESULT IN SEAS IN THE GULF STREAM BUILDING
RAPIDLY TO AROUND 7 FEET. THESE CONDITIONS ARE EXPECTED THROUGH
SUNDAY MORNING WHEN THE BOUNDARY FINALLY MOVES NORTH OF THE AREA.
A SMALL CRAFT ADVISORY WILL BE ISSUED FOR THE ATLANTIC WATERS
TONIGHT THROUGH SUNDAY MORNING. SEAS AND WINDS SHOULD GRADUALLY
SUBSIDE AFTER THAT. WINDS SHOULD INCREASE OVER THE REST OF THE
WATERS AS WELL, BUT WL REMAIN BELOW SMALL CRAFT ADV CRITERIA,
NEVERTHELESS A CAUTION STATEMENT WILL BE INDICATED FOR THE GULF
WATERS AND LAKE OKEECHOBEE.

&&

.FIRE WEATHER...NO PROBLEMS EXPECTED AS DEW POINTS SHOULD INCREASE
SIGNIFICANTLY AS THE BOUNDARY MOVES NORTH RESULTING IN RH VALUES
WELL ABOVE CRITICAL LEVELS.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  69  80  71  84 / 50 60 30 10 
FORT LAUDERDALE  71  80  74  83 / 50 60 20 10 
MIAMI            70  81  72  84 / 50 60 20 10 
NAPLES           63  83  68  85 / 40 50 20 10 

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST SUNDAY 
     FOR AMZ650-AMZ651-AMZ670-AMZ671.

GM...NONE.
&&

$$

SHORT TERM/LONG TERM/MARINE/FIRE...47/RGH
AVIATION...50/RLP