AFDEYW
FLORIDA KEYS AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1020 AM EDT SAT JUN 12 2004
.DISCUSSION...
.OBSERVATIONS/TRENDS...
THE KEY WEST MORNING SOUNDING REVEALED DEEP-LAYER GEOPOTENTIAL
HEIGHT RISES IN ASSOCIATION WITH A STRENGTHENING UPPER RIDGE FROM
THE SOUTHWEST CARIBBEAN TO THE SOUTHEAST UNITED STATES. MEANWHILE...
A CYCLONIC VORTEX CENTERED OVER THE NORTHWEST TIP OF THE YUCATAN
PENINSULA HAS DEVELOPED DOWNWARD...AND NOW HAS A SURFACE LOW
PRESSURE REFLECTION OVER THE BAY OF CAMPECHE. RECENT GOES-12
INFRARED SATELLITE LOOPS SHOW NEW CONVECTIVE CLUSTERS DEVELOPING
WEST OF MERIDA...MEXICO...NORTHEAST OF THE SURFACE LOW. ALSO...
DIFLUENT FLOW BETWEEN AN UPPER TROUGH OVER THE SOUTHWESTERN GULF OF
MEXICO AND THE UPPER RIDGE OVER THE CARIBBEAN IS ENHANCING
CONVECTIVE CELL COVERAGE OVER WESTERN CUBA AND THE YUCATAN CHANNEL.
THE MORNING SOUNDING ALSO INDICATED AN EXTREMELY MOIST AND UNSTABLY
STRATIFIED AIR MASS OVER THE KEYS...WITH LITTLE CONVECTIVE
INHIBITION. DESPITE THE MOIST AND UNSTABLE AIR MASS...KEY WEST
DOPPLER RADAR IS VOID OF ANY DEEP CONVECTION...SHOWING ONLY AREAS OF
LIGHT RAIN FALLING OUT OF THICK MID/UPPER CLOUD DECKS.
.AFTERNOON FORECASTS...
WINDS THIS MORNING HAVE BEEN QUITE LIGHT...AVERAGING 5-10KT MOST
PLACES. THEREFORE...FIRST PERIOD WINDS WILL BE LOWERED A FEW KNOTS.
WE WILL SEE AN INCREASING CHANCE FOR SHOWERS AND THUNDERSTORMS AS
THE AFTERNOON PROGRESSES...DUE TO NORTHWARD-MOVING CONVECTIVE
CLUSTERS FROM OVER WESTERN CUBA AND ASSOCIATED BOUNDARIES. THERE MAY
BE SOME SPRINKLES OR LIGHT RAIN EARLY THIS AFTERNOON...THANKS TO
THICK MID/UPPER CLOUD DECKS.
&&
.MARINE...
WINDS MAY EVEN SLACKEN A BIT MORE THIS AFTERNOON AS THE ATLANTIC
RIDGE GETS PINCHED BY A PENINSULAR HEAT TROUGH.
&&
.AVIATION...
MAINLY VFR CONDITIONS WILL PERSIST FOR THE KEYW AND KMTH
TERMINALS...AS WELL AS THE KMIA-KEYW AIR ROUTE FOR THE NEXT 24
HOURS. MVFR CONDITIONS CAN BE ANTICIPATED IN DEVELOPING SHOWER
ACTIVITY THIS AFTERNOON...AND IFR CONDITIONS WILL OCCUR IN ISOLATED
THUNDERSTORM ACTIVITY. THE BEST CHANCE FOR THUNDERSTORMS WILL BE
THIS AFTERNOON FOR THE SOUTH FLORIDA MAINLAND...AND THIS EVENING AND
OVERNIGHT FOR THE KEYS AND ADJACENT WATERS.
&&
.EYW WATCHES/WARNINGS/ADVISORIES...NONE.
$$
PUBLIC/MARINE/GRIDS...K. KASPER
AVIATION/NOWCASTS.....L. KASPER
Thoughts and comments welcomed.
Robert





