Area Forecast Discussion
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000
FXUS62 KKEY 220842
AFDKEY

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
442 AM EDT WED OCT 22 2014

.DISCUSSION...A DEEP AND EXPANSIVE CYCLONIC GYRE PREVAILS ACROSS THE
NORTHEASTERN UNITED STATES...DEFORMING AND PRESSING THE SUBTROPICAL
RIDGE DEEP INTO THE WESTERN ATLANTIC. TO THE WEST OF THE CYCLONE...AN
UPPER LEVEL RIDGE AXIS EXTENDS FROM MEXICO INTO THE CANADIAN
PRAIRIES. WATER VAPOR LOOPS REVEAL SEVERAL SPOKES OF ENERGY ROTATING
AROUND THE CYCLONE...CULMINATING IN A CONFLUENT AND ACCELERATING JET
EAST OF FLORIDA. NESTLED IN THE BAY OF CAMPECHE...RECENTLY FORMED
TROPICAL DEPRESSION (TD) #9 CREEPS EAST AT 6 MPH...SOUTH OF A
DENIGRATED AND BROAD BAROCLINIC ZONE WHICH BISECTS THE GULF OF
MEXICO. MIMIC TPW LOOPS SUMMARIZE OUR FINDINGS...DEEP TROPICAL
MOISTURE ACROSS THE WESTERN CARIBBEAN AND THE SOUTHERN GULF OF
MEXICO...BATTLING THE TRANSGRESSION OF THE CONTINENTAL AIRMASS TO ITS
NORTH. THE SURFACE PATTERN PLACES THE KEYS VERY NEAR A COL
REGION...HENCE THE SQUIRRELY BREEZES. DESPITE ALL THE
VARIABILITY...MEAN SURFACE WINDS ARE FROM THE EAST AT AROUND 10
KNOTS. THE RADAR HAS BEEN SURPRISINGLY QUIET OVERNIGHT.

.SHORT TERM (TODAY THROUGH FRIDAY)...THE CURRENT FORECAST FROM THE
NATIONAL HURRICANE CENTER SLIDES TD 9 SLOWLY EAST ACROSS THE YUCATAN
PENINSULA.

THE BROAD BAROCLINIC ZONE STALLED ACROSS CENTRAL FLORIDA WILL INCH
SOUTHWARD TODAY. A REINFORCING SHOT OF CONTINENTAL AIR WILL SHARPEN
ITS GRADIENT TONIGHT. THROUGH THIS TIME FRAME...FLOW WILL BE WEAKLY
CYCLONIC...MOISTURE WILL BE PLENTIFUL...AND INHIBITION WILL BE
MINIMAL. THE ICING ON THE CAKE WILL BE THE FAVORABLE VENTING ALOFT.
FOR THURSDAY THROUGH FRIDAY...ONE JET-STREAK WILL HAVE MIGRATED EAST
INTO THE WESTERN ATLANTIC...ONLY TO BE REPLACED BY A STRONGER
COUNTERPART. THIS SECOND STREAK WILL BE THE LEADING HALF OF
SHARPENING SHORT WAVE TROUGH WHICH WILL STEER THE BAROCLINIC ZONE
SOUTHWARD. ALL-THE- WHILE...STRENGTHENING LOW LEVEL FLOW WILL BECOME
MORE CYCLONIC...A MISMASH OF THE STRETCHED TD AND THE ENCROACHING
FRONTAL BOUNDARY. TO SUMMARIZE...CATEGORICAL RAIN CHANCES TODAY
THROUGH THURSDAY...FOLLOWED BY LIKELY CHANCES THURSDAY NIGHT AND
FRIDAY. WE DO NOT FEEL CHANCES LOWER THROUGH THE SHORT TERM...BUT
GIVEN THE UNCERTAINTY WITH DAY 3...WILL RETAIN THE INHERITED
FORECAST.

&&

.LONG TERM (FRIDAY NIGHT THROUGH TUESDAY)...A DIGGING SHORT WAVE
WILL HERALD A DRYING WEATHER PATTERN. FRIDAY NIGHT AND SATURDAY WILL
FEATURE A SHARP DROP-OFF IN RAIN CHANCES...ACCOMPANIED BY FRESHENING
NORTH TO NORTHEASTERLY BREEZES. LOWER HUMIDITY...SLIGHTLY COOLER
TEMPERATURES...AND BREEZY CONDITIONS WILL PREVAIL SATURDAY NIGHT
THROUGH SUNDAY NIGHT. A STACKED AND DEEP ANTICYCLONE ACROSS THE
SOUTHEASTERN UNITED STATES WILL SLOWLY MIGRATE EASTWARD MONDAY
THROUGH TUESDAY...ALLOWING MODERATE TO FRESH NORTHEAST BREEZES TO
SLOWLY VEER TO THE EAST.

&&

.MARINE...THE COMBINATION OF A CONTINENTAL HIGH PRESSURE SYSTEM
CENTERED OVER THE EASTERN UNITED STATES AND A TROPICAL LOW PRESSURE
AREA CENTERED NEAR THE YUCATAN WILL MAINTAIN A RICH VEIN OF TROPICAL
MOISTURE INTO THE FLORIDA KEYS TODAY THROUGH FRIDAY. A NEARLY
STATIONARY FRONTAL ZONE JUST NORTH OF THE FLORIDA KEYS WILL PROVIDE
THE FOCUS FOR SEVERAL EPISODES OF HEAVY RAIN OVER SOUTHERN FLORIDA
DURING THE NEXT FEW DAYS. THE FRONTAL ZONE WILL MERGE WITH THE
TROPICAL LOW PRESSURE AREA IN THE VICINITY OF THE FLORIDA KEYS FRIDAY
THROUGH SATURDAY...RESULTING IN FRESHENING NORTHEAST TO EAST BREEZES
ACROSS ALL FLORIDA KEYS COASTAL WATERS.

&&

.AVIATION...A MUCH WETTER THAN NORMAL WEATHER PATTERN HAS SPREAD
ACROSS THE FLORIDA KEYS AND BROADER SURROUNDING AREA. AS A
RESULT...PERIODS OF MVFR/IFR CONDITIONS CAN BE EXPECTED AT THE ISLAND
TERMINALS OVER THE NEXT SEVERAL DAYS. CURRENTLY...A BREAK IN THE
WEATHER IS KEEPING VFR CONDITIONS AT THE TERMINALS...AND THESE
CONDITIONS SHOULD PREVAIL THROUGH MUCH OF THE MORNING HOURS. SURFACE
WINDS WILL BE LIGHT OUT OF THE EAST TO SOUTHEAST...BUT CAN BE STRONG
AND GUSTY NEAR THE STRONGER SHOWERS AND THUNDERSTORMS.

&&

.PRELIMINARY POINT TEMPS/POPS...
KEY WEST  83  75  83  75 / 80 80 80 70
MARATHON  83  75  83  75 / 80 80 80 70

&&

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

$$

PUBLIC/MARINE.........CLR
AVIATION/NOWCASTS.....11
DATA COLLECTION.......FLING

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