Area Forecast Discussion
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000
FXUS62 KKEY 210218
AFDKEY

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
920 PM EST SAT DEC 20 2014

.DISCUSSION...
.CURRENTLY...
KBYX DETECTS NO PRECIPITATION ECHOES. SKIES OVER THE ISLAND CHAIN
ARE VARIABLY CLOUDY. WINDS OVER LAND ARE EAST AT 5 TO 10 MPH. C-MAN
WINDS...ON AVERAGE...ARE EAST TO SOUTHEAST NEAR 10 KNOTS.
TEMPERATURES ARE IN THE LOWER TO MID 70S.

.SHORT TERM (OVERNIGHT)...
IN THE LOW LEVELS OF THE ATMOSPHERE...A BROAD AREA OF LOW PRESSURE
WILL BE CENTERED OVER THE CENTRAL GULF OF MEXICO OVERNIGHT. IN THE
MID LEVELS OF THE ATMOSPHERE...AN ATLANTIC RIDGE OF HIGH PRESSURE
WILL EXTEND ACROSS CUBA TONIGHT. IN THE UPPER LEVELS OF THE
ATMOSPHERE...ZONAL FLOW WILL PREVAIL OVERNIGHT. THE 00Z KKEY
SOUNDING IS MARGINALLY UNSTABLE AND QUITE MOIST FOR THIS TIME OF
YEAR...WITH A PRECIPITABLE WATER (PWAT) VALUE JUST ABOVE ONE AND ONE
HALF OF AN INCH. ATMOSPHERIC MOISTURE WILL INCREASE OVERNIGHT. BY
SUNRISE SUNDAY...PWAT VALUES WILL BE JUST BELOW ONE AND THREE
QUARTERS OF AN INCH...WHICH IS WELL ABOVE NORMAL FOR THE LATTER HALF
OF DECEMBER. DESPITE ADEQUATE ATMOSPHERIC INSTABILITY AND ABUNDANT
MOISTURE IN PLACE TO SUPPORT CONVECTION...LACK OF AN APPARENT
CONVECTIVE TRIGGER WILL BE RESPONSIBLE FOR MEASURABLE RAIN CHANCES
OF NEAR ZERO IN THE FLORIDA KEYS OVERNIGHT.

&&

.MARINE...
GENTLE EAST TO SOUTHEAST BREEZES WILL PREVAIL ON ALL KEYS COASTAL
WATERS OVERNIGHT. NO ADVISORIES OR CAUTIONARY HEADLINES EXPECTED
TONIGHT THROUGH AT LEAST TUESDAY. SUSTAINED SOUTH TO SOUTHWEST
SURFACE WINDS OF 15 TO 20 KNOTS ARE POSSIBLE ON THE COASTAL WATERS
OF THE ATLANTIC AND OFFSHORE GULF OF MEXICO TUESDAY NIGHT AND
WEDNESDAY MORNING. A SMALL CRAFT ADVISORY WILL LIKELY BE REQUIRED
FOR THE COASTAL WATERS OF THE ATLANTIC AND OFFSHORE GULF OF MEXICO
WEDNESDAY AFTERNOON. SMALL CRAFT ARE URGED TO EXERCISE CAUTION ON
THE COASTAL WATERS OF FLORIDA BAY AND NEARSHORE GULF OF MEXICO
WEDNESDAY AFTERNOON DUE TO SUSTAINED SOUTH TO SOUTHWEST SURFACE
WINDS OF 15 TO 20 KNOTS. A SMALL CRAFT ADVISORY WILL LIKELY BE
REQUIRED FOR ALL KEYS COASTAL WATERS WEDNESDAY NIGHT AND THURSDAY
MORNING. SMALL CRAFT ARE URGED TO EXERCISE CAUTION ON THE COASTAL
WATERS OF THE ATLANTIC AND OFFSHORE GULF OF MEXICO THURSDAY
AFTERNOON DUE TO SUSTAINED NORTHEAST SURFACE WINDS OF 15 TO 20
KNOTS. NO ADVISORIES OR CAUTIONARY HEADLINES EXPECTED THURSDAY NIGHT.

&&

.AVIATION...
EXPECT VFR CONDITIONS AT BOTH THE KEY WEST AND MARATHON TERMINALS
THROUGH 21/12Z. THEREAFTER...POTENTIAL MVFR CEILINGS MAY DROP BELOW
2K FEET. WINDS WILL REMAIN OUT OF THE EAST TO SOUTHEAST LESS THAN 10
KNOTS...WHILE VEERING AROUND TO WEST TO NORTHWEST ABOVE 7K FEET.

&&

.CLIMATE...
ON THIS DATE IN FLORIDA KEYS WEATHER HISTORY...IN 1973...2.50 INCHES
OF RAIN FELL AT KEY WEST INTERNATIONAL AIRPORT. THIS SET THE DAILY
RECORD FOR MAXIMUM RAINFALL MEASURED IN KEY WEST ON DECEMBER 20TH...
A RECORD WHICH STILL STANDS 41 YEARS LATER. RAINFALL RECORDS AT KEY
WEST DATE BACK TO 1871.

&&

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

&&

$$

PUBLIC/MARINE/FIRE/DIGITAL...BS
AVIATION/CLIMATE.............BWC

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