Area Forecast Discussion
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000
FXUS62 KKEY 181336
AFDKEY

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
936 AM EDT THU SEP 18 2014

.DISCUSSION...
.CURRENTLY...
A LONG WAVE TROUGH IS DIGGING THROUGH THE MID ATLANTIC AND OFF THE
FLORIDA EAST COAST THIS MORNING. SATELLITE SHOWS THE WEAKENING TROUGH
TO OUR NORTH WHILE THE KBYX RADAR IS PICKING UP SCATTERED SHOWERS
WITH A FEW THUNDERSTORMS ON THE GULF WATERS NORTH OF THE ISLAND
CHAIN. THE MORNING SOUNDING IS QUITE WET WITH TWO AND ONE QUARTER
INCHES OF PWAT. SKIES ARE MOSTLY CLOUDY DUE TO THE MID TO HIGH LEVEL
CLOUDINESS. THE NEARBY TROUGH HAS WEAKENED THE PRESSURE FIELD AROUND
THE KEYS CONSIDERABLY...RESULTING IN LIGHT AND VARIABLE WINDS OUTSIDE
OF SHOWERS PRODUCING GUSTS TO AROUND 15 KNOTS.

.FORECAST...
THE TROUGH WILL SLIDE TO THE EAST LEAVING THE WEAK PRESSURE REGIME
OVER THE KEYS AREA. HIGH MOISTURE...COOLING IN THE LOW TO MID
LEVELS...AND A MODERATELY UNSTABLE MORNING SOUNDING WOULD SUGGEST
ALL THAT IS NEEDED IS A KICKER. HEATING WILL BE LIMITED DUE TO THE
MID TO HIGH LEVEL CLOUDINESS SO THIS KICKER WILL NEED TO COME FROM
MORE MESO SCALE AND DYNAMICAL PROCESSES....WHICH MAY BE IN THE FORM
OF OUTFLOW BOUNDARIES OFF THE ACTIVITY TO THE NORTH. THE LOW LEVEL
FLOW...ALTHOUGH LIGHT...IS SLIGHTLY CONFLUENT BELOW 700 MB AND
CONCENTRATED SLIGHTLY NORTH OF THE KEYS...AND MAY HELP TRIGGER
ADDITIONAL SHOWERS AND THUNDERSTORMS THERE. HAVE LOWER COVERAGE OVER
THE STRAITS BUT WILL KEEP CHANCE SHOWERS AND SLIGHT CHANCE
THUNDERSTORMS FOR THE ISLAND CHAIN WITH SCATTERED SHOWERS AND
THUNDERSTORMS OVER THE MARINE ENVIRONMENT TO THE NORTH.

&&

.MARINE...
WEAKNESS IN THE PRESSURE FIELD WILL CONTINUE THROUGH AT LEAST
SATURDAY RESULTING IN LIGHT WINDS WITH A FOCUS FROM THE
WEST...SOUTH TO SOUTHWEST TO NORTHWEST TO NORTH. A RIDGE WILL BUILD
IN NORTH OF THE AREA LATE IN THE WEEKEND SHIFTING WINDS BACK TO AN
EAST TO SOUTHEAST DIRECTION.

&&

.AVIATION...
UNTIL 00Z/19TH...OUTSIDE OF A SUB-VFR EPISODE OR TWO...VFR CONDITIONS
WILL PREVAIL AT THE KEY WEST AND MARATHON TERMINALS. SOUTHWEST TO
WEST WINDS OF AROUND 5 KNOTS WILL BECOME WEST NORTHWEST AT LESS THAN
10 KNOTS THIS AFTERNOON.

&&

.CLIMATE...
ON THIS DATE IN KEYS WEATHER HISTORY...1926...THE GREAT MIAMI
HURRICANE MADE LANDFALL ON MIAMI BEACH EARLY MORNING SEPTEMBER 18TH.
MAXIMUM SUSTAINED WINDS IN MIAMI WERE REPORTED AROUND 145 MPH WITH A
MINIMUM CENTRAL PRESSURE OF 930 MB OR 27.46 INCHES OF MERCURY. IN KEY
WEST THE PEAK WIND WAS 52 MPH WITH A MINIMUM PRESSURE 998 MB OR
29.48 INCHES OF MERCURY.

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...NONE.
&&

$$

PUBLIC/MARINE.........BWC
AVIATION/NOWCASTS.....APA
DATA COLLECTION.......VICKERY

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