FXUS62 KMFL 260130
AFDMFL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
830 PM EST FRI DEC 25 2009
.UPDATE...THE FRONT IS MOVING THROUGH SOUTHWEST FLORIDA ATTM WITH
WIDELY SCATTERED DECREASING SHOWERS IN ADVANCE OVER CENTRAL
BROWARD AND MIAMI DADE COUNTIES AND THE ATLANTIC WATERS. THE
SHOWERS AND THE FRONT ARE MOVING QUITE SLOW AT AROUND 10 MPH, SO
THINK THE FRONT SHOULD MAKE IT TO THE EAST COAST BY MIDNIGHT. HAVE
EARLIER REMOVED MENTION OF THUNDER IN ZFP UPDATE. HAVEN'T SEEN ANY
LIGHTNING AND WITH THE SUBSIDENCE INVERSION AT 11000 FEET, THAT IS
ONE OF THE REASONS IT DIDN'T OCCUR ALONG WITH LACK OF HEATING. ALL
THAT'S LEFT WILL BE 10-20 PERCENT CHC SHOWERS EAST SECTIONS UNTIL
AROUND MIDNIGHT. WILL REMOVE ALL HAZARDS FROM THE HWO.
&&
.PREV DISCUSSION... /ISSUED 640 PM EST FRI DEC 25 2009/
AVIATION...
MAINLY VFR CONDITIONS ARE EXPECTED ACROSS THE SOUTH FLORIDA
TERMINALS THROUGHOUT THE PERIOD. A COLD FRONT HAS ALREADY PASSED
THROUGH KAPF AND IT IS EXPECTED TO MOVE THROUGH THE EAST COAST
TERMINALS BETWEEN 04Z AND 06Z. AS IT MOVES THROUGH THIS WILL VEER
THE WINDS AROUND TO 270 AND THEN EVENTUALLY TO 320 BY MORNING. WINDS
AT KAPF HAVE ALREADY SHIFTED TO THE NORTHWEST. SHOWER ACTIVITY HAS
STOPPED AT KAPF, AND VCSH WILL CONTINUE ACROSS THE EAST COAST
TERMINALS UNTIL THE FRONT PASSES.
CWC
PREV DISCUSSION... /ISSUED 139 PM EST FRI DEC 25 2009/
DISCUSSION...A WEAKENING LINE OF SHRA CONTINUES TO MOVE INTO THE
SW COAST THIS AFTERNOON ALONG THE PREFRONTAL TROF. THIS LINE WILL
CONTINUE TO SLOWLY BREAK UP AS IT RUNS INTO A MORE UNIDIRECTIONAL
WIND FIELD AND MORE STABLE CONDITIONS. THE COLD FRONT IS ABOUT
100 MILES BEHIND THE TROF. DECIDED TO SLASH POPS ACROSS THE AREA
INTO THE CHC CAT AS PRECIP IS NOT VERY WIDE SPREAD AND THE LINE
CONTINUES TO DWINDLE IN INTENSITY, HOWEVER SOME SHRA AND POSSIBLY
EVEN A TS WILL REMAIN POSSIBLY THROUGH THE AFTERNOON WITH DIURNAL
HEATING. THE COLD FRONT WILL LIMP DOWN INTO THE STRAIGHTS TONIGHT AND
STALL THROUGH THE WEEKEND AS THE BIG MIDWEST LOW SLOWLY SWIRLS
AROUND TOWARD THE GREAT LAKES. AS THE LOW OVER THE MID WEST/GREAT
LAKES AREA MEANDERS ABOUT, A WEAK SHORT WV WILL ROUND THE BASE OF
THE TROF ACROSS TX AND LA ALLOWING FOR A WEAK LOW TO FORM IN THE
WESTERN GULF. THIS WEAK LOW MAY ALLOW THE WEAK FRONT ACROSS THE
STRAIGHTS TO LIFT BACK TO THE NORTH POTENTIALLY INTO S FL SLIGHTLY
INCREASING POPS SUNDAY AND MONDAY, BUT BY LATE MONDAY/EARLY TUES
THE GREAT LAKES LOW WILL BE WEAKENING AND LIFTING OUT WHICH WILL
FINALLY ALLOW FOR THE COLD FRONT TO RESUME ITS SOUTHWARD JOURNEY
INTO THE CARIBBEAN AND THEREFORE A DAY OF SLIGHTLY BELOW NORM
TEMPS ON TUES AND POSSIBLY INTO WED MORN. A RIDGE WILL THEN BUILD
ACROSS THE EASTERN HALF OF THE COUNTRY THROUGH MID WEEK WITH WINDS
GRADUALLY BECOMING EASTERLY THEN SE BY LATE WED AND THURS ONCE
AGAIN INCREASING MOISTURE AND TEMPS AHEAD OF THE NEXT FRONT THAT
WILL APPROACH THE AREA AT THE END OF THE WEEK.
AVIATION...TIMING AND COVERAGE OF SHRA AND ISOLATED TS MAIN CONCERN.
EXP SCT SHRA AT BEST POSSIBLE WITH ISOLD TS THIS AFTERNOON AND
EVENING ALL TERMINALS WITH BRIEF PERIODS OF MVFR CONDITIONS
POSSIBLE. NO IFR CONDITIONS ANTICIPATED AT THIS TIME BUT CANNOT
TOTALLY RULE OUT. SO HANDLING SITUATION OVERALL WITH VCSH. ENDING
VCSH AT KAPF AROUND 00Z THIS EVENING AND AROUND 08Z EAST COAST
TERMINALS. CDFNT WITH WIND SHIFT EXPECTED TO MOVE THROUGH KAPF EARLY
THIS EVENING AND AROUND MIDNIGHT/EARLY MORNING HOURS EAST COAST
TERMINALS. THERE IS CONCERN FOR CEILINGS IN THE 010-030 RANGE OVER
NEXT COUPLE OF HOURS WITH CURRENT CLOUD MASS ACROSS SOUTHEAST
TERMINALS AND BEHIND LEADING LINE OF SHOWERS AT KAPF. THEN AGAIN
OVERNIGHT FOR EAST COAST TERMINALS WITH/BEHIND FRONT. BUT GIVEN
UNCERTAINTY JUST LEFT A FEW-SCT DECK IN THAT TIME RANGE.
MARINE...NW WINDS WILL SLIGHTLY INC TONIGHT BEHIND A COLD FRONT
THAT WILL MOVE THROUGH, HOWEVER SPEEDS ARE EXPECTED TO REMAIN LESS
THAN 20 KTS. THIS WIND INCREASE WILL RESULT IN BUILDING SEAS,
ESPECIALLY IN OUT GULF WATERS AND GULF STREAM, BUT HEIGHTS ARE
EXPECTED TO REMAIN BELOW SCA CRITERIA. THE W TO NW FETCH ACROSS
THE GULF MAY RESULT IN A SMALL SWELL SAT MORN THROUGH SUN MORN,
BUT IN THE ATLANTIC ATTM DECIDED TO CUT OUT THE FORECASTED SWELL
AS GUIDANCE APPEARS UNREALISTIC WITH THE WAVE GENERATED WITH THE LIGHT
WINDS AND SMALL FETCH EXPECTED.
FIRE WEATHER...NO PROBLEMS OR CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 63 75 61 76 / 20 10 20 20
FORT LAUDERDALE 65 76 64 77 / 20 10 20 20
MIAMI 66 77 65 79 / 20 10 20 20
NAPLES 61 73 56 74 / 10 10 10 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
LONG TERM...18/GR
SHORT TERM/AVIATION...CWC
