NWS AFD Key West

[TampaFl]

FXUS62 KEYW 070714
AFDEYW

FLORIDA KEYS AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
300 AM EDT TUE SEP 7 2004

.DISCUSSION...
.OBSERVATIONS/TRENDS...
FRANCES IS NOW A TROPICAL DEPRESSION NORTH OF FLORIDA MOVING
NORTH/NORTHWEST ALONG THE SOUTHERN GEORGIA/ALABAMA BORDER. PRESSURE
GRADIENT REMAINS TIGHT DOWN MOST OF THE WEST COAST OF FLORIDA WITH A
CONTINUED BUT GRADUAL SLACKENING NOTICED ACROSS THE LOCAL AREA.
BREEZES ARE MODERATE TO FRESH FROM THE SOUTH/SOUTHWEST. CMANS ON
AVERAGE ARE STILL RANGING FROM 15 TO 20 KNOTS WITH A FEW HIGHER
GUSTS. KBYX RADAR HAS SHOWN LIMITED ECHOES N/S ORIENTED FROM THE
WATERS SURROUNDING KEY WEST NORTHWARD TO THE MAINLAND NEAR NAPLES.
OTHER SCATTERED ECHOES ARE ALSO NOTED JUST BEYOND THE WESTERN EDGES
OF OUR GULF ZONES.

.FORECASTS...
HIGH PRESSURE IN THE ATLANTIC IS NOSING SOUTHWESTWARD...WITH AN AXIS
ACROSS THE BAHAMAS AND THE WESTERN HALF OF CUBA. GOES SOUNDER
INDICATES AN AREA OF DRIER AIR JUST EAST OF THE BAHAMA HEADING TO
THE WEST/SOUTHWEST. BOTH THE ETA AND GFS PULLS THIS AREA TO THE
STRAITS AND KEYS AREA TODAY AND TONIGHT...WITH THE ETA PORTRAYING
SIGNIFICANTLY DRIER CONDITIONS OVER THE LOCAL AREA WEDNESDAY AND
THURSDAY AND THE GFS KEEPING A DEEPER MOISTURE AXIS ALIGNED ALONG
AND ON THE NORTHERN REACHES OF THE ISLAND CHAIN DURING THAT TIME.
WILL STICK CLOSER TO THE GFS WHICH MAINTAINS A MORE VEERED FLOW
THROUGH WEDNESDAY NIGHT AND POPS A GOOD 10 PERCENT HIGHER THROUGH 36
HOURS...AND 20 TO 30 PERCENT HIGHER FOR WEDNESDAY NIGHT AND THURSDAY
THAN THE ETA. THIS IS ALSO CLOSER TO WHAT WE ALREADY HAVE
ADVERTISED. THE ONLY CHANGE IN THE FORECAST MAY BE A SMALL DOWNWARD
ADJUSTMENT IN GRIDS FOR THURSDAY...BUT KEEPING US IN THE CHANCE
RANGE.

FOR FRIDAY AND BEYOND...THE LAST SEVERAL TRACKS OF IVAN HAVE
SUCCESSIVELY DIPPED THE COURSE THROUGH THE CARIBBEAN...AND
EVENTUALLY NEAR WESTERN CUBA BY LATE SATURDAY. THAT FORCES SOME
CHANGES IN THE WIND GRIDS LATE THIS WEEK...BUT WILL MAINTAIN A
MODERATE TO HIGH CHANCE OF PRECIPITATION UNTIL WE SEE A MORE
DIFINITIVE REASON TO ADJUST.
&&
.MARINE...
A FEW SHIP REPORTS NEAR OUR COASTAL WATERS INDICATE LINGERING HIGH
WAVES AND SWELLS. ALTHOUGH THE WINDS WILL DECREASE AN ADDITIONAL 5
KNOTS OR SO THROUGH THE COURSE OF THE DAY...WILL MAINTAIN THE SMALL
CRAFT ADVISORY FOR SEAS IN BOTH THE GULF AND ATLANTIC ZONES...AT
LEAST THROUGH THIS MORNING. WILL ALSO HANG ON TO AN EXERCISE CAUTION
IN THE BAY DUE TO THE LATEST WIND OBS. NO OTHER CHANGES IN THE
UPCOMING COASTAL FORECAST.
&&

.AVIATION...
VFR CONDITIONS WILL PREVAIL ACROSS THE KMIA-KEYW AIR ROUTE AT THE
KEYS AND KMTH TERMINALS FOR THE NEXT 24 HOURS. ISOLATED MVFR SHOWERS
AND THUNDERSTORMS ARE EXPECTED. AVERAGE TOPS ~FL350 WITH MAX TOPS
FL450. MEAN WIND VECTOR IS 170/10KT. SURFACE WIND GUSTS OF 30 KNOTS
ARE POSSIBLE IN THE STRONGER CELLS.
&&

.PRELIMINARY POINT TEMPS/POPS...
KEY WEST 89 81 89 80 / 50 50 50 40
MARATHON 90 81 91 80 / 50 50 50 40
&&

.EYW WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY FOR GMZ032-033-052-053-054-072-073-074-075.
&&

$$

PUBLIC/MARINE/DIGITAL...........MR
AVIATION/NOWCASTS...............D. FELTGEN