FXUS62 KMFL 241454
AFDMFL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
954 AM EST THU DEC 24 2009
.UPDATE...CURRENTLY A TROF LIES EAST TO WEST ACROSS THE STRAITS,
AND THIS WILL DRIFT NORTHWARD THROUGH TODAY AS A LOW MOVES
NORTHEAST ACROSS ARKANSAS. AS THIS TROF MOVES NORTH INTO S FL
THIS AFTERNOON AND THIS EVENING SURFACE CONVERGENCE AND MOISTURE
WILL INCREASE, HOWEVER FOR MOST OF TODAY... REGARDING TSRA... THE
AREA WILL BE TOO STABLE TO RESULT IN MUCH IF ANY THUNDERSTORMS.
THE IMMEDIATE EAST COAST AND ATLANTIC WILL HAVE THE BEST SHOT AT
ANY TSRA, BUT EVEN THAT IS VERY SLIM. THIS EVENING AND TONIGHT,
PWATS WILL INCREASE TO ABOVE 1.5" WHILE THE AREA IS UNDER UPPER
DIVERGENCE, AND A BIT OF CONVERGENCE AT THE SURFACE... THIS WILL
LEAD TO AN INCREASE IN STORMS. SO WITH THAT SAID DECIDED TO TRIM
OUT THE TSRA FOR TODAY/THIS AFTERNOON EXCEPT FOR ALONG THE IMMEDIATE EAST
COAST AND FOR THIS EVENING AND TONIGHT ALLOWED THE MENTION OF
THUNDER TO OCCUR OVER THE REMAINDER OF THE AREA. /TINGLER
&&
.PREV DISCUSSION... /ISSUED 610 AM EST THU DEC 24 2009/
AVIATION...VFR ALL TERMINALS THRU PD. HIGH PRES REMAINS IN PLC
ALG U.S. E COAST AND OFSHR OVR ATLC OFF THE SE U.S. COAST AND
THOUGH SFC LOW OVER XTRM SE BAHAMAS PULLING AWAY TO THE NE...PRES
GRAD REMAINS HI ACRS S FLA AS ANOTHR SFC LOW DEEPENS OVR THE SRN
GRT PLAINS. THUS...A STG ESE WND FLOW DVLPG WI BKN-OVC CLDS 040-070
KFT WITH HIR LYRS. ATTM BRO/MIAMI DADE TERMINALS AFFECTED ONLY WITH
VRY -RA...MNLY OFSHR...BUT WITH NO MVFR CIG/VSBY XPCTD. VCSH INTRO
TO ALL E COAST TERMINALS AFT 18Z. WNDS E-ESE 10-15 KTS WITH GUSTS
AOB 20 KTS AFT 14Z. AT KAPF ENE WND 10 KTS BCMG E-ESE 10-13G20KTS
AFT 14Z WITH VCSH AFT 18Z. TSRA PSBL ALL TERMINALS AFT 16Z BUT
ISOLD IN NATURE AND NOT IN TAFS BUT CB DECK IN CLDS.
PREV DISCUSSION... /ISSUED 417 AM EST THU DEC 24 2009/
DISCUSSION...
STARTING THIS AFTERNOON THROUGH THE WEEKEND...MOISTURE AND
CLOUDINESS WILL INCREASE ACROSS SOUTH FLORIDA AND ADJACENT WATERS.
TODAY THE SURFACE AND LOW LEVEL FLOW WILL BECOME MORE SOUTHEASTERLY
IN ADVANCE OF A DEVELOPING LOW PRESSURE SYSTEM AND ASSOCIATED FRONT
CURRENTLY ACROSS TEXAS...WITH THE SURFACE LOW FORECAST TO DEEPEN AND
MOVE TO THE NNE AND APPROACH THE GREAT LAKES BY FRIDAY. THIS WILL
BRING INCREASING MOISTURE ACROSS THE REGION AND INCREASE THE CHANCE
OF SHOWERS TODAY AND CHRISTMAS DAY...WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS POSSIBLE ACROSS THE REGION TODAY AND TONIGHT
AND BY CHRISTMAS DAY MORE NUMEROUS SHOWER ACTIVITY AND ISOLATED
THUNDERSTORMS IS POSSIBLE. WHILE THE SUITE OF MODEL GUIDANCE HAS
BEEN PRETTY CONSISTENT WITH THESE FEATURES THE LAST COUPLE OF
DAYS...THE LATEST GUIDANCE AND MOST RECENT WATER VAPOR IMAGERY
INDICATE THE SOUTHERN EXTENT OF THE MID TO UPPER LEVEL LOW HAS
REACHED SOUTHERN TEXAS AND INTO THE NORTHERN GULF. THIS IS A BIT OF
A DEPARTURE FROM PREVIOUS GUIDANCE AND MAY ALLOW SOME SOME
ADDITIONAL DYNAMICS AND ENERGY TO BE A LITTLE FURTHER SOUTH THAN
PREVIOUS FORECASTS. THEREFORE...A SLIGHT CHANCE OF THUNDERSTORMS HAS
BEEN INCLUDED IN TODAYS AND CHRISTMAS DAYS FORECAST. HOWEVER...THE
RECENT GUIDANCE DOES INDICATE THAT SOUTH FLORIDA AND ADJACENT WATERS
MAY ALSO BE UNDER A WEAK MID TO UPPER LEVEL RIDGE DURING THIS
PERIOD...WHICH MAY HELP TO SUPPRESS ANY THUNDERSTORMS. AT ANY
RATE...SLIGHT CHANCE OF THUNDERSTORMS WAS INCLUDED IN THE FORECAST.
AS PWATS COULD REACH AROUND 1.7 INCHES TODAY THROUGH FRIDAY...THERE
COULD BE ISOLATED AREAS OF LOCALLY HEAVY RAINFALL. BY SATURDAY
GUIDANCE SUGGESTS THAT THE FRONT MAY STILL BE LINGERING OVER THE
SOUTHERN PENINSULA AND/OR THE FLORIDA STRAITS...WITH NORTH TO
NORTHEASTERLY FLOW ACROSS THE REGION WHICH COULD BRING SOME
ADDITIONAL SHOWER ACTIVITY TO THE REGION THROUGH THE WEEKEND WITH NO
FORCING EVIDENT THAT WOULD DRIVE THE LINGERING BOUNDARY AWAY FROM
THE REGION.
THE TEMPERATURES WILL REMAIN FAIRLY WARM THROUGH THE FORECAST
PERIOD...WITH THE FRONT NOT HAVING MUCH IMPACT...JUST A SLIGHT
COOLING EFFECT.
MARINE...
REGIONAL WIND OBSERVATIONS AND THE LATEST GUIDANCE INDICATE THAT
WINDS ACROSS THE OFF SHORE ATLANTIC WATERS AND THE OFF SHORE GULF
WATERS COULD BE ON THE ORDER OF 22 KNOTS OR MAYBE EVEN A BIT
ABOVE. FOR THE ATLANTIC WATERS THE HIGHER WINDS ARE MAINLY EAST OF
MIAMI DADE AND BROWARD COUNTIES. THEREFORE...A SMALL CRAFT ADVISORY
IS IN EFFECT FOR THESE WATERS INCLUDING BISCAYNE BAY THROUGH 00Z FRIDAY.
FIRE WEATHER...
NO FIRE WEATHER CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 73 80 61 / 30 50 60 30
FORT LAUDERDALE 79 73 80 64 / 40 50 60 30
MIAMI 79 72 81 66 / 40 50 60 30
NAPLES 81 67 79 61 / 30 40 60 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ630-
AMZ651-AMZ671.
GM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR GMZ676.
&&
$$
LONG TERM...04/AT
SHORT TERM/AVIATION...52/PS
