FXUS62 KMFL 301544
AFDMFL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
1044 AM EST MON NOV 30 2009
.UPDATE...SURFACE RIDGE FROM THE ATLANTIC TO THE LAKE AREA WILL
MOVE SLOWLY SOUTH TODAY. THIS WILL PRODUCE WEAK WIND FLOW AND NICE
WEATHER WITH GOAD BOATING CONDITIONS OVER THE LOCAL WATERS. MADE A
FEW WIND CHANGES AND UPDATED TEMPS, DEWPOINTS AND HUMIDITIES ON
THE GRIDS. BASICALLY NOT MUCH CHANGE TO FCSTS ATTM.
&&
.PREV DISCUSSION... /ISSUED 614 AM EST MON NOV 30 2009/
AVIATION...
THE WINDS TODAY WILL BE FROM THE SOUTHEAST AT 5 TO 10 KNOTS BEFORE
GOING LIGHT AND VARIABLE TONIGHT AFTER 23Z ALONG THE EAST COAST
TAF SITES. AT KAPF TAF SITE...THE WINDS WILL BE SOUTHEAST THIS
MORNING BEFORE SWINGING TO A WESTERLY DIRECTION AROUND 18Z TODAY
AT 5 TO 10 KNOTS. THE WX WILL BE DRY THROUGH TONIGHT WITH THE VIS
AND CEILING IN THE VFR CONDITIONS.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 333 AM EST MON NOV 30 2009/
SHORT TERM...TODAY THROUGH TUESDAY...LOW LEVEL HIGH PRESSURE
RIDGE OVER THE WRN ATLANTIC WILL CONTINUE TO MOVE EAST AS AN UPPER
LEVEL TROUGH MOVES TO THE EASTERN SEABOARD. THE LIGHT LOW LEVEL
FLOW WILL BEGIN TO SHIFT TO SE AND THEN SOUTH AS THIS HAPPENS
WITH A GRADUAL INCREASE IN LOW LEVEL MOISTURE. THIS INCREASE IN
MOISTURE COMBINED WITH THE LIGHT FLOW COULD RESULT IN FOG
DEVELOPING MAINLY OVER INLAND AREAS TONIGHT...HOWEVER NO DENSE FOG
IS EXPECTED AT THIS TIME AND ONLY PATCHY FOG WILL BE INDICATED IN
THE FORECAST. THERE MAY BE AN ISOLD SHOWER HERE AND THERE,
HOWEVER NO SIGNIFICANT PRECIP IS EXPECTED DURING THIS PERIOD.
LONG TERM...WEDNESDAY THROUGH FRIDAY...MODELS CONTINUE TO
FORECAST THE DEVELOPMENT OF A FRONTAL LOW ACROSS THE NRN GULF OF
MEXICO BY TUE NIGHT. IN FACT...GFS HAS A GOOD INITIALIZATION OF
THE OVERALL LONG WAVE PATTERN WITH A "SEMI" CUT-OFF LOW OVER BAJA
CALIFORNIA/NRN MEXICO MOVING EAST TO ERN TX BY WEDNESDAY AND TO SE
U.S. BY WEDNESDAY NIGHT AS AN OPEN WAVE BEING ABSORBED BY A LONG
WAVE TROUGH. ECMWF HAS BASICALLY THE SAME INITIALIZATION BUT MOVES
THE CUT-OFF LOW A BIT SLOWER ( FURTHER NORTH) AT THE BEGINNING AND
THEN ACCELERATES IT NORTHEASTWARD CLEARING NEW ENGLAND BEFORE
FRIDAY MORNING. WHILE BOTH MODELS MOVE THE FRONT ACROSS THE LOCAL
AREA SOMETIME THURSDAY AFTERNOON/EVENING (GFS NOW HAS SLOWED DOWN
A GOOD DEAL) THE MAIN DIFFERENCE BETWEEN THE MODELS IS THE
LOCATION OF THE BEST DYNAMICS (THEREFORE MOST ACTIVE WEATHER) WITH
RESPECT TO SOUTH FLORIDA. ECMWF KEEPS THE STRONGEST UPPER LEVEL
DYNAMICS WELL TO THE NORTH WITH THE STRONGEST/HEAVIEST CONVECTION
STAYING FROM CENTRAL FLORIDA NORTHWARD AS THE FRONT MOVES THROUGH
THURSDAY. GFS ON THE OTHER HAND...WHILE KEEPING THE BEST DYNAMICS
OVER SE U.S., STILL SHOWS GOOD UPPER LEVEL DIVERGENCE OVER THE
WHOLE PENINSULA...AND A GOOD 40-50 KTS LOW LEVEL JET OVER SOUTH
FLORIDA MAINLY WEDNESDAY EVENING THROUGH THURSDAY MORNING. WHILE
THIS IS SLIGHTLY DIFFERENT THAN THE PREVIOUS RUN (24 HRS AGO), IS
STILL CLOSE ENOUGH TO INCREASE THE CONFIDENCE IN THE LIKELIHOOD OF
A VERY ACTIVE CONVECTIVE ACTIVITY OVER SOUTH FLORIDA WED
NIGHT/THU. SHOULD GFS BE RIGHT...WE COULD SEE A FEW STRONG, AND
EVEN ONE OR TWO SEVERE, STORMS DURING THIS PERIOD. THE PRESENCE OF
THE LOW LEVEL JET ALONG COULD RESULT IN WIND GUSTS OF 40 TO 50 KTS
ASSOCIATED WITH THE STRONGEST CONVECTION. WILL GO CLOSER WITH GFS
OUTPUT AS CONFIDENCE HAS INCREASED DUE TO A GOOD INITIALIZATION. ALTHOUGH
IS TOO EARLY TO MENTION THIS IN THE ZFP, IT WILL BE INDICATED IN
THE EXTENDED PORTION OF THE HAZARDOUS WEATHER OUTLOOK (HWO). THE
FRONT SHOULD MOVE SOUTH OF THE AREA BY THURSDAY NIGHT AND SO A
DRYING TREND WILL BE INDICATED BY FRIDAY.
SATURDAY THROUGH SUNDAY...A LOW LEVEL RIDGE WILL MOVE EAST FROM
THE MID-ATLANTIC COAST OVER THE WRN ATLANTIC WITH THE LOW LEVEL
FLOW SHIFTING TO ESE ADVECTING PATCHES OF MOISTURE/CLOUDS BACK
OVER SOUTH FLORIDA
MARINE...PLEASANT BOATING CONDITIONS SHOULD CONTINUE OVER ALL
SOUTH FLORIDA'S WATERS THROUGH TUESDAY WITH WINDS BELOW 15 KTS AND
SEAS BELOW 4 FEET. SFC WINDS SHOULD SHIFT TO SE/S AND INCREASE IN
SPEED BY TUESDAY NIGHT POSSIBLY REACHING SMALL CRAFT ADVISORY
CRITERIA (>20 KNOTS). WINDS SHOULD CONTINUE TO INCREASE IN SPEED
THROUGH THURSDAY AND SHIFT TO NORTHWEST AS THE FRONT MOVES
THROUGH. THIS WILL RESULT IN RATHER ROUGH AND HAZARDOUS CONDITIONS
OVER ALL WATERS FROM MID-WEEK TO POSSIBLY THE END OF THE WEEK.
FIRE WEATHER...NO PROBLEMS EXPECTED. RELATIVE HUMIDITY VALUES
ARE EXPECTED TO REMAIN WELL ABOVE 35% THROUGH THE ENTIRE FORECAST
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 81 62 80 72 / - - 10 10
FORT LAUDERDALE 81 66 80 73 / - - 10 10
MIAMI 82 66 81 72 / - - 10 10
NAPLES 81 62 81 68 / - - 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
LONG TERM...18/GR
SHORT TERM/AVIATION...54/BNB
