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000
FXUS62 KKEY 230835
AFDKEY

AREA FORECAST DISCUSSION FOR THE FLORIDA KEYS
NATIONAL WEATHER SERVICE KEY WEST FL
330 AM EST SUN NOV 23 2014

.DISCUSSION...IN THE MID AND UPPER LEVELS...700-200 MB...LATEST
AVAILABLE IR IMAGERY AS OF 300 AM...OVERLAID WITH AVAILABLE MODEL
STREAMLINE ANALYSIS DETAILS LARGE SCALE TROUGHING REMAINS IN PLACE
ACROSS THE BREADTH OF THE CONUS INCLUDING NORTHERN OLD MEXICO AND
THE GULF OF MEXICO...WITH SOME SPLITTING OF THE DEEPER MAIN TROUGH
AXIS ACROSS THE LENGTH OF THE PLAINS DOWN TO TEXAS. THE CENTER OF A
REGIONAL SCALE MID AND UPPER ANTICYCLONE IS FIXED OVER THE WESTERN
CARIBBEAN SEA.

AT THE SURFACE AND IN THE LOWER TO MID LEVELS...SURFACE TO 700 MB.
LATEST AVAILABLE IR IMAGERY AS OF 300 AM DEPICT THE CENTER OF A 1030
MB SURFACE ANTICYCLONE RESPONSIBLE FOR BREEZY TO WINDY CONDITIONS
ACROSS THE KEYS DURING THE PAST SEVERAL DAYS HAS SHIFTED TO ABOUT 65
WEST 35 NORTH. A WEAK SURFACE/LOW LEVEL WARM FRONT HAS LIFTED
NORTHWARD INTO SOUTHEASTERN FLORIDA...SO WINDS ARE NOW
SOUTHEASTERLY. AS A RESULT...LAST EVENINGS 00Z SOUNDING STILL
ILLUSTRATED A FRESH TO STRONG AND MOIST EAST TO SOUTHEAST FLOW FROM
OFF THE SURFACE TO 5 KFT...WITH PWAT NEAR 2.00 INCHES.

.CURRENTLY...AS OF 300 AM...SKIES ARE PARTLY CLOUDY ACROSS THE
ISLANDS AND SURROUNDING WATERS. RADAR ONLY DETECTS A COUPLE TINY
SHOWERS IN THE STRAITS. C-MAN STATIONS ALONG THE REEF ARE SOUTHEAST
AT 15 TO 20 KNOTS. ISLAND SENSORS ARE SOUTHEAST NEAR 15 MPH.
TEMPERATURES ACROSS THE ISLANDS ARE IN THE MID TO UPPER 70S WITH
DEWPOINTS IN THE MIDDLE 70S.

.FORECASTS...A DRIER...WARMER...MORE HUMID...AND LESS WINDY WEATHER
PATTERN BEGINS TODAY AND CONTINUES THROUGH TUESDAY NIGHT. CAN EXPECT
SUNSHINE TO RETURN IN ABUNDANCE AS WELL. AS THE WESTERN ATLANTIC
CONTINUES TO PULL EASTWARD TODAY...LOCAL WINDS WINDS WILL VEER MORE
SOUTHEAST...DIMINISHING TO 10 TO 15 KNOTS ON ALL WATERS BY AFTERNOON
AND TONIGHT. WINDS BECOME SOUTHERLY AND LIGHT TO GENTLE ON MONDAY
AND THEN VARIABLE ON MONDAY NIGHT. DESPITE THE MOSTLY SUNNY
CONDITIONS EACH DAY AND CLEAR SKIES AT NIGHT...LATEST AVAILABLE
MODEL FORECAST SOUNDINGS STILL ILLUSTRATED COLUMNAR PWAT
(PRECIPITABLE WATER) IS AROUND 1.50 INCHES THRU MONDAY. THEREFORE
SOME LIGHT SHOWERS MAY WANDER ACROSS THE KEYS LATER AT NIGHT AND
TOWARDS MORNING...ERGO WILL STILL KEEP A DIME POP IN THE GRIDS
THROUGH MONDAY.

MONDAY NIGHT AND TUESDAY...MODELS CONSISTENT WITH INDICATIONS THE
NEXT SHORTWAVE DIVING OUT OF THE PLAINS CARVES OUT A NARROW YET
SHARP LONGWAVE TROUGH THAT SWEEPS ACROSS THE PLAINS MONDAY
NIGHT...THEN ACROSS THE GULF OF MEXICO TUESDAY AND REACHES THE
FLORIDA PENINSULA AND THE KEYS BY WEDNESDAY. THE SYSTEM SWEEPS A
COLD FRONT SOUTHEASTWARD ACROSS THE NORTHERN GULF MONDAY...REACHING
NORTHERN AND CENTRAL FLORIDA TUESDAY...SOUTHERN FLORIDA TUESDAY
NIGHT...THEN BLASTS THROUGH THE KEYS WEDNESDAY MORNING AS STRONG AND
CHILLY SURFACE HIGH PRESSURE BUILDS ACROSS THE NORTHWESTERN GULF
COAST AND EAST TEXAS. MODEL FORECAST SOUNDINGS BEGIN TO INCREASE
LOWER TO MID LEVEL MOISTURE AS EARLY AS MONDAY NIGHT AND TUESDAY
WELL AHEAD OF THE FALLING MID LEVEL HEIGHT...WITH SOME ISENTROPIC
LIFT AND COLUMNAR PWAT INDICATED AND PWAT CLIMBING TO BETWEEN 1.75
AND 2.00 INCHES MONDAY NIGHT AND TUESDAY. POPS ARE LOW TO MID CHANCE
FOR THESE TWO PERIODS.

FOR TUESDAY NIGHT AND WEDNESDAY INCREASED PREFRONTAL MOISTURE
AND SOME UPPER DYNAMICS IN THE REAR QUADRANT OF THE APPROACHING
TROUGH OVER THE GULF WILL PROVIDE BETTER CHANCES FOR SHOWERS AND
THUNDERSTORMS. FOR NOW WILL MAINTAIN JUST ISOLATED THUNDERSTORMS IN
THE GRIDS...BUT SLIGHTLY BETTER DYNAMICS ARE FAVORED BY THE ECMWF
AND COVERAGE OF THUNDERSTORMS MAY NEED TO BE INCREASED IF THIS
SCENARIO BECOMES CONSISTENT WITH SUBSEQUENT RUNS. GIVEN DEEPER
MOISTURE AND INSTABILITY PRESENT...HIGH CHANCE POPS ARE ALREADY IN
THE GRIDS FOR THESE TWO PERIODS. HIGH TEMPERATURES TODAY THROUGH
TUESDAY WILL REACH THE LOWER TO MID 80S WITH OVERNIGHT LOWS IN THE
LOWER TO MID 70S AND HIGH LEVELS OF HUMIDITY.

BY WEDNESDAY AFTERNOON MODEL FORECAST SOUNDINGS DELINEATE WELL THAT
THE SURFACE FRONT WILL MOVE ACROSS THE KEYS...BUT DEEPER MOISTURE
REMAINING IN THE COLUMN ABOVE IN ASSOCIATION WITH ANOTHER GOOD
FRONTAL INVERSION...AND ASSOCIATED OVERRUNNING HEAVY SHOWERS/AND OR
RAINFALL EXPECTED THROUGH LATE WEDNESDAY. ALL PRECIPITATION SHOULD
CLEAR OUT AFTER SUNSET AS VERY DRY AIR FILTER IN RAPIDLY AND GOOD
1000-850 MB COLD THICKNESS ADVECTION ENSUES WEDNESDAY NIGHT.
TEMPERATURES SHOULD HOLD IN THE 70S DURING WEDNESDAY...FALLING INTO
THE UPPER 50S LATE WEDNESDAY NIGHT WITH THE ONSET OF THE STRONGER
COOL AIR ADVECTION BEHIND THE FRONT.

THANKSGIVING DAY THROUGH SATURDAY...COOL NEAR 1030 MB HIGH PRESSURE
OVER THE GULF COAST STATES ON THANKSGIVING CONDITIONS WILL LEAD TO
CLEAR...WINDY...DRY...AND COOL CONDITIONS ACROSS THE KEYS THROUGH
THESE PERIODS. MARINE CONDITIONS WILL LIKELY BE GREATLY IMPEDED FOR
RECREATIONAL BOATERS AND SOME TRANSITING. HIGH TEMPERATURES WILL BE
ONLY IN THE HIGH 60S TURKEY DAY...REACHING THE LOWER TO MID 70S
FRIDAY AND SATURDAY...WITH LOWS IN THE 50S AGAIN THURSDAY
NIGHT...AND 60 OR BETWEEN FRIDAY NIGHT.

&&

.MARINE...A SMALL CRAFT ADVISORY WILL BE RETAINED THIS MORNING
ACROSS THE FLORIDA STRAITS GIVEN DEVELOPED SEAS AND SOUTHEAST WINDS
NEAR 20 KNOTS...WITH CAUTIONARY HEADLINES ACROSS ALL OTHER WATERS IN
THE MARINE DISTRICT. A CAUTIONARY HEADLINE MAY STILL BE REQUIRED
ACROSS THE FLORIDA STRAITS THIS AFTERNOON. WINDS AND SEAS WILL LET
DOWN TONIGHT THROUGH TUESDAY NIGHT...AND HEADLINES AND ADVISORIES
ARE NOT ANTICIPATED ANYWHERE MONDAY THRU TUESDAY NIGHT. SMALL CRAFT
APPEAR LIKELY ON ALL WATERS BY LATE WEDNESDAY AFTERNOON OR
EVENING...WITH OCCASIONAL GUSTS BETWEEN 30 AND 35 KNOTS WEDNESDAY
NIGHT AND THURSDAY. SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE
THRU THE REST OF THE WEEK ON ALL WATERS.

&&

.AVIATION...VFR CONDITIONS WILL PREVAIL AT BOTH THE KEY WEST AND
MARATHON TERMINALS THROUGH SUNDAY AFTERNOON. THERE IS A SLIGHT
CHANCE OF A PASSING SHOWER...BUT THE PROBABILITY OF SUCH AN EVENT
RESULTING IN PROLONGED FLIGHT RESTRICTIONS IS TOO LOW TO INCLUDE IN
THE TERMINAL FORECAST. SURFACE WINDS WILL BE FROM THE SOUTHEAST
BETWEEN 5 AND 10 KNOTS.

&&

.PRELIM POINT TEMPS/POPS...
KEY WEST  84  75  84  75  / -  10  10  10
MARATHON  84  76  85  76  / -  10  10  10

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GM...SMALL CRAFT ADVISORY THROUGH 22Z
GMZ042-044&GMZ055-054&GMZ072-075&GMZ033-034

&&

$$

PUBLIC/MARINE/GRIDS.........FUTTERMAN
AVIATION/NOWCASTS...........DEVANAS

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