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000
FXUS62 KKEY 271959
AFDKEY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
300 PM EST FRI FEB 27 2015

.DISCUSSION...IN THE MID AND UPPER LEVELS...(700-200 MB)LATEST
AVAILABLE IR IMAGERY OVERLAID WITH MODEL STREAMLINE ANALYSIS AS OF
200 PM STILL DETAILS A LARGELY CYCLONIC MID AND UPPER FLOW PATTERN
IN PLACE ACROSS THE ENTIRE CONUS...WITH 75 TO 100 KNOT
SOUTHWESTERLIES AT 250 MB RIDING ACROSS FLORIDA AND THE KEYS FROM
CENTRAL MEXICO.

AT THE SURFACE AND IN THE LOWER TO MIDDLE LEVELS...SURFACE TO 700
MB...LATEST IR IMAGERY OVERLAID WITH AVAILABLE MARINE AND LAND
SURFACE OBSERVATIONS AND ANALYSIS DETAIL A 1040 MB CENTER OF A LATE
WINTER ARCTIC AIRMASS CENTERED NEAR THE QUAD CITIES. LOCALLY...A
STATIONARY SURFACE FRONT REMAINS IN THE FLORIDA STRAITS SOUTHEAST OF
THE KEYS.

.CURRENTLY...AS OF 200 PM...SKIES HAVE BECOME PARTLY CLOUDY TO
MOSTLY SUNNY ACROSS THE KEYS AND ADJOINING WATERS...EXCEPT MIDDLE
AND UPPER CLOUDINESS HAS REMAINED ACROSS THE OFFSHORE GULF WATERS
AND WESTERN STRAITS. FOR THAT REASON TEMPERATURES HAVE REACHED INTO
THE MIDDLE AND UPPER 70S...WITH DEWPOINTS IN THE UPPER 60S. C-MAN
STATIONS ALONG THE REEF REMAIN NORTHEAST  10 TO 15 KNOTS FROM SOMBRERO
KEY NORTHEAST...BUT NEAR 15 KNOTS AND GUSTY OUT TO THE DRY TORTUGAS.

.SHORT TERM...WEAKLY CYCLONIC MID AND UPPER FLOW PATTERN AT 500 WILL
BECOME WEAKLY ANTICYCLONIC BY SATURDAY THROUGH EARLY NEXT WEEK AS
MODELS BUILD 500 MB HEIGHTS NORTHWARD OUT OF THE CARIBBEAN SEA AND
SOUTHERN GULF...SUNDAY THROUGH WEDNESDAY. STRONG 1040 MB ARCTIC
RIDGING NOW OVER THE UPPER MIDWEST WILL RACE TO NEAR NEW JERSEY BY
SUNDAY...THEN MOVE INTO THE WESTERN ATLANTIC AS A 1035 MB HIGH
SUNDAY NIGHT. 1030 MB HIGH OVER GIORGIA BUILDS IN SUNDAY NIGHT BUT
IS REINFORCED BY YET ANOTHER STRONGER 1035 MB PLUS HIGH OVER THE
MIDWEST WHICH ASSERTS CONTROL AND BUILDS SOUTHEASTWARDS TO THE NORTH
CAROLINA COAST BY WEDNESDAY. BOTH GFS AND ECMWF MODEL FORECAST
SOUNDINGS HAVE BEEN MORE MOIST IN THE BOUNDARY LAYER AND SINCE MID
LEVELS WILL BE WARMING AND DRYING OUT...BUT WITH LOWER LEVEL
CONVERGENCE/LATE NIGHT AND EARLY MORNING WILL BE THE PRIMARY
MECHANISM TO GENERATE ISOLATED SHOWERS. SO KEPT IN 20 PERCENT FOR
TONIGHT FOR ISOLATED SHOWERS...BUT THEREAFTER BELIEVE IN LESSER
BOUNDARY LAYER MOISTURE AND STRONGER LOWER LEVEL CONVERGENCE SO WILL
MAINTAIN A 10 POP IN THE GRIDS THROUGH THE PERIOD GIVEN BREEZY
CONDITIONS BEGINNING LATE TONIGHT AND LASTING THROUGH THE MIDDLE OF
NEXT WEEK. HIGH TEMPERATURES AROUND 80 CAN BE EXPECTED WITH
OVERNIGHT LOWER NEAR OR ABOVE 70 DEGREES THRU ENTIRE PERIOD.

WEDNESDAY NIGHT THRU FRIDAY...LOOKS LIKE ANOTHER FRONT WILL APPROACH
SOUTH FLORIDA AND THE KEYS...AND EXPECT WINDS TO CLOCK MORE
SOUTHEASTERLY AND DECREASE. TEMPERATURES WILL BE A FEW DEGREES
WARMER WITH HIGHS IN THE LOWER 80S AND LOWS IN THE LOWER TO MID 70S.

&&

.MARINE...HAVE KEPT A SPLIT GIVEN THE SLOWER INCREASE IN MAGNITUDE
OF THE WINDS THANKS TO A DYING TROUGH TO THE IMMEDIATE SOUTHEAST OF
THE KEYS. THEN SMALL CRAFT WILL NEED TO EXERCISE CAUTION ACROSS ALL
WATERS BY TOMORROW MORNING...WITH SMALL CRAFT ADVISORY CONDITIONS
EXPECTED BY SUNDAY ACROSS THE FLORIDA STRAITS CONTINUING THROUGH AT
LEAST MONDAY. ITS POSSIBLE THAT SCA CONDITIONS WILL BE REQUIRED
ACROSS HAWK CHANNEL AND THE OFFSHORE GULF WATERS AS WELL. WINDS AND
SEAS SHOULD COME DOWN SLIGHTLY BY WED AND WED NIGHT.

.AVIATION...
VFR CONDITIONS ARE EXPECTED AT THE KEY WEST AND MARATHON TERMINALS
THROUGH LATE THIS EVENING. MVFR CEILINGS ARE POSSIBLE BRIEFLY
THROUGH THAT TIME AT KEY WEST. MVFR AND POSSIBLE IFR CEILINGS MAY
REDEVELOP MORE SUBSTANTIALLY LATER IN THE OVERNIGHT PERIOD AT BOTH
LOCATIONS AS NORTHERLY WINDS TIP MORE TO THE EAST/NORTHEAST AND
RANGE FROM 10 TO 15 KNOTS.

&&

.CLIMATE... ON THIS DATE IN KEYS WEATHER HISTORY...IN 1989...THE
TEMPERATURE IN KEY WEST DIPPED TO 46 DEGREES. THIS SET THE DAILY LOW
TEMPERATURE RECORD FOR FEBRUARY 27 IN KEY WEST. TEMPERATURE RECORDS
FOR KEY WEST DATE BACK TO 1872.

&&

.PRELIMINARY POINT TEMPS/POPS...
KEY WEST  69  78  73  78 / 20 10 10 10
MARATHON  71  79  73  79 / 20 10 10 10

&&

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

$$

PUBLIC/MARINE.........FUTTERMAN
AVIATION/NOWCASTS.....04
DATA COLLECTION.......PARKE

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