FXUS62 KMFL 261202
AFDMFL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
702 AM EST SAT DEC 26 2009
.AVIATION...
THERE ARE NO MAJOR CHANGES TO THE FORECAST FROM 26/06Z TAF
ISSUANCE...WITH VFR CONDS AND A GENERAL CLEARING TREND EXPECTED
FOR REMAINDER OF PERIOD. HOWEVER...WITH STRONG WESTERLY FLOW
ALOFT...SCT MID/HIGH-LEVEL CLOUD COVER WILL LIKELY CONTINUE TO
AFFECT ALL TERMINALS. SURFACE WINDS EAST COAST TERMINALS WILL
REMAIN NW/NNW THRU SUNDAY MORNING...WITH SPEEDS RANGING FROM 5-10
KNOTS. WIND FORECAST IS SIMILAR FOR APF...BUT WITH LIGHT NNE FLOW
EXPECTED AFTER 27/00Z.
70/DD
&&
.PREV DISCUSSION... /ISSUED 355 AM EST SAT DEC 26 2009/
DISCUSSION...
WEAKENED COLD FRONT HAS PASSED THROUGH ALL OF SOUTH FL AND LIES
ACROSS THE STRAITS EARLY THIS MORNING...AND SHOULD NOT MAKE MORE
THAN A SLOW SAG AWAY FROM THE REGION TODAY AS IT LOSES ITS PUSH
AND PARALLELS STEERING FLOW. SOME PATCHY FOG HAS FORMED ACROSS THE
INTERIOR AND LAKE OKEECHOBEE REGION EARLY THIS MORNING AS SKIES
HAVE CLEARED WITH LIGHT TO CALM WINDS...BUT THIS SHOULD BURN OFF
QUICKLY AFTER SUNRISE. SWRLY FLOW THROUGH A DEEP LAYER N OF THE
FRONT MAY KEEP SOME HIGH CLOUDS AROUND TODAY...BUT THE RESULT
SHOULD STILL BE A DRY DAY. THIS GENERAL PATTERN WILL PERSIST INTO
SUNDAY...WITH PERHAPS AN INCREASE IN CLOUDS LATER SUNDAY AND
SUNDAY NIGHT AS A WEAK MID- LEVEL DISTURBANCE PASSES JUST N OF THE
REGION. MODEL GUIDANCE DOES INDICATE THAT A FEW SHOWERS MAY BE
POSSIBLE SUNDAY AFTERNOON INTO EARLY MONDAY MORNING AS THE
DISTURBANCE PASSES...BUT FCST SOUNDINGS FROM THE NAM AND GFS DO
NOT REALLY SHOW SUFFICIENT SATURATION BELOW THE MID-LEVELS WHICH
SHOULD LIMIT ANY ACTIVITY TO A FEW SPRINKLES OR LIGHT SHOWERS AS
IT SEEMS NOW AS ANOTHER FRONT GETS DRAGGED ACROSS THE REGION.
A BRIEFLY...BUT NOTICEABLY COOLER AND DRIER AIRMASS WILL WORK INTO
THE REGION MONDAY AFTERNOON INTO TUESDAY AS A STRONG SFC RIDGE
BUILDS SOUTH INTO THE MID MISSISSIPPI VALLEY. MONDAY NIGHT STILL
APPEARS TO BE THE COOLEST NIGHT AS 1000-850MB THICKNESSES ARE
STILL FCST TO DROP TO AROUND 1345M ACROSS THE NW INTERIOR. THIS
SHOULD SUPPORT LOW TEMPS IN THE LOWER 40S THERE...WITH 40S
ELSEWHERE ACROSS THE INTERIOR AND 50S ALONG THE COASTS AND METRO
AREAS. SOME MODERATION WILL TAKE PLACE TUESDAY AND ESPECIALLY
TUESDAY NIGHT...MOST NOTICEABLY ACROSS THE EAST COAST. INTERIOR
AREAS MAY STILL DECOUPLE AS THE SFC RIDGE SHIFTS E TO THE MID ATLC
COAST...BUT MODELS HAVE BEEN CONSISTENTLY ADVERTISING A SHALLOW
BUT MODERATE TO STRONG ERLY WIND SURGE ALONG THE E COAST TUESDAY
AFTERNOON AND NIGHT. THEREFORE...EXPECT MAYBE 1-3 DEGREES WARMING
ACROSS THE INTERIOR TUESDAY NIGHT BUT MORE ACROSS THE EAST COAST.
THIS MODERATION TREND WILL CONTINUE INTO WEDNESDAY AS A NEW
DISTURBANCE RIDES OUT OF THE SW CONUS AND IGNITES SFC
CYCLOGENESIS MOVING NE ACROSS THE NRN GULF OF MEXICO INTO
THURSDAY...AND RETURN FLOW OCCURS AHEAD OF THIS DVLPG SYSTEM. THE
GFS/ECMWF HANDLE THE SYSTEM SOMEWHAT DIFFERENTLY...WITH BOTH
MODELS TAKING THE SYSTEM JUST OFF THE CONUS E COAST BUT WITH THE
ECMWF MUCH STRONGER WITH THE LOW AND MORE AGGRESSIVE WITH THE
FRONT...WHILE THE GFS STALLS THE FRONT OVER THE REGION FOR A DAY
OR TWO BEFORE PUSHING IT THROUGH. REGARDLESS...BOTH MODELS
INDICATE THAT A COLDER AIRMASS COULD FOLLOW THIS SYSTEM TO RING IN
THE NEW YEAR.
MARINE...
WAVEWATCH GUIDANCE CONTINUES TO ADVERTISE A 3FT SWELL AFFECTING
THE PALM BEACH COUNTY COAST TODAY WITH LESSER AMOUNTS FURTHER
SOUTH...BUT THIS AGAIN SEEMS TO BE IN ERROR AS JUPITER WEBCAM JUST
BEFORE SUNSET YESTERDAY WAS COMPLETELY FLAT. BUOY 41010 IS
REPORTING SWELL BUT THE PERIOD IS ONLY AROUND 9S...SO HAVE KEPT
SWELLS OUT OF THE FCST FOR NOW. SHOULD BE FAIRLY BENIGN BOATING
CONDITIONS THE NEXT SEVERAL DAYS...WITH WINDS LESS THAN 15KTS AND
SEAS GENERALLY 4FT OR LESS ACROSS ALL WATERS. NWRLY WINDS OF
15-20KTS AND BUILDING SEAS ARE PSBL MONDAY INTO TUESDAY BEHIND THE
PASSING COLD FRONT.
FIRE WEATHER...
NO CONCERNS THROUGH THE WEEKEND. DRIER AIRMASS WILL MOVE INTO THE
REGION ESPECIALLY TUESDAY FOR A BRIEF PERIOD...BUT RH'S ARE FCST
TO REMAIN JUST ABOVE CRITICAL LEVELS DUE TO EXPECTED COOLER
DAYTIME MAX TEMPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 74 55 73 59 / - 10 20 20
FORT LAUDERDALE 76 59 76 65 / - 10 20 20
MIAMI 76 62 76 65 / - 10 20 20
NAPLES 70 53 72 56 / - 10 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
LONG TERM...65/GS
SHORT TERM/AVIATION...70/DD
