Coastal Flood Statement 2, NWS Key West, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
320 AM EDT SAT SEP 26 2015

.DISCUSSION...IN THE MID AND UPPER LEVEL...(700-200 MB)...LATEST
AVAILABLE IR IMAGERY OVERLAID WITH MODEL STREAMLINE ANALYSIS AS 300
AM...ILLUSTRATE A EXPANSIVE DEEP MIDDLE AND UPPER TROUGH SITUATED
FROM THE OHIO VALLEY WESTWARD TO THE CENTRAL PLANS THENCE SOUTHWARDS
TO THE SOUTHERN MEXICAN GULF COAST. SOUTHEAST OF THAT...AN UPPER
RIDGE IS IN PLACE AT 250 MB OVER THE WESTERN CARIBBEAN SEA...BUT
WITH TROUGHING IN THE MIDDLE LEVELS REMAINING ACROSS SOUTH
FLORIDA...THE KEYS...DOWN TO CUBA AND THE CARIBBEAN SEA.

AT THE SURFACE AND THE THE LOWER TO MIDDLE LEVELS...AS OF 300 AM...A
STATIONARY TROUGH EXTENDS FROM A FEW HUNDRED MILES EAST OF THE
CAROLINAS WESTWARD TO GEORGIA. BROAD LOWER PRESSURE IS LOCATED FROM
THE YUCATAN PENINSULA INTO THE WESTERN CARIBBEAN SEA. LAST EVENINGS
00Z SOUNDING ILLUSTRATED A GENTLE AND VERY MOIST LOWER TO MID
TROPOSPHERE WITH EAST WINDS VEERING TO SOUTHWEST ABOVE 700 MB.

.CURRENTLY...SKIES ARE PARTLY CLOUDY ACROSS THE ISLANDS AND
ADJOINING WATERS OWING TO SOME MID AND UPPER CLOUDINESS. RADAR
DETECTS ONLY ISOLATED SHOWERS AND A FEW THUNDERSTORMS SURROUNDING
THE KEYS ISLAND CHAIN...WITH THE BULK OF THE ACTIVITY ACROSS THE
GULF WATERS AND WESTERN FLORIDA STRAITS. TEMPERATURES ACROSS THE
ISLANDS REMAIN IN THE LOWER 80S WITH DEWPOINTS IN THE UPPER 70S. C-
MAN STATIONS ALONG THE REEF ARE REGISTERING EAST TO SOUTHEAST WINDS
NEAR 10 KNOTS...BUT AN EARLIER ASCAT PASS REGISTERED 10 TO 15 KNOTS
IN THE CENTRAL AND WESTERN FLORIDA STRAITS.

.SHORT TERM...TODAY THROUGH MONDAY NIGHT...WEAK RIDGING TO THE NORTH
OF THE KEYS WILL BE RESPONSIBLE FOR GENTLE EAST TO SOUTHEAST WINDS.
ALTHOUGH THE LOWER TO MID TROPOSPHERE REMAINS QUITE MOIST...WITH
MODEL FORECAST SOUNDINGS ILLUSTRATING PWAT BETWEEN 1.75 AND 2.00
INCHES...LITTLE LARGE SCALE FORCING IS AVAILABLE TO GENERATE LOW
CHANCE FOR POPS...AND THE LOWER TO MID LEVEL SOUTHEAST FLOW IS NOT
CONDUCIVE FOR THE MESOSCALE SHOWER MACHINE...SO ONLY ISOLATED POPS
WILL BE INSERTED IN THE GRIDS. BY TONIGHT AND DURING SUNDAY WINDS
WILL BEGINNING TO PICK UP IN RESPONSE TO MOVEMENT FARTHER NORTH OF
THE AFOREMENTIONED SURFACE TROUGH OVER THE WESTERN CARIBBEAN SEA.

THE SURFACE REFLECTION WILL DEEPEN A FEW MILLIBARS AS IT FORMS WELL
SOUTHWEST OF THE KEYS TONIGHT AND SUNDAY...WHICH WILL KEEP SLIGHTLY
ELEVATED CONFLUENT FLOW...DESPITE RIDGING TO THE NORTH OF THE KEYS.
THE TROUGH WILL DEVELOP INTO A LOW PRESSURE AS IT MOVE NORTHWARD
ACROSS THE SOUTHERN...THEN CENTRAL AND NORTHERN GULF DURING SUNDAY
NIGHT THRU MONDAY NIGHT. WINDS AND SEAS MAY BE HIGHER ACROSS THE
WESTERN WATERS...AND THE OFFSHORE GULF 20 TO 60 NM WEST OF MAINLAND
MONROE COUNTY. FOR NOW HAVE JUST INCREASED WIND TO NEAR 15
KNOTS...AS THE MODELS TEND TO UNDERDO THE SYNOPTIC GRADIENT WITH
THESE TYPE OF SYSTEMS. WILL MAINTAIN LOW CHANCES FOR SHOWERS AND
THUNDERSTORMS GIVEN THE THE LOWER LEVEL CONFLUENT FLOW INTO THIS
SYSTEM WILL BE COUNTERING SOME MIDDLE LEVEL DRYER AIR ASSOCIATED
WITH THE RIDGING WELL TO THE NORTH. DAYTIME HIGH TEMPERATURES WILL
REACH INTO THE UPPER 80S AND LOWS NEAR 80...EXCEPT 75 TO 80 IN
RAINSHOWERS AND STORMS.

THERE REMAINS A SET OF ASTRONOMICAL CIRCUMSTANCES ASSOCIATED WITH A
SUPERMOON EXPECTED BY SUNDAY EVENING...WHICH WILL CONTINUE TO LEAD
TO ELEVATED TIDES THROUGH THE REST OF THIS WEEKEND AND EARLY NEXT
WEEK. THEREFORE...RESIDENTS IN LOW LYING AREAS PRONE TO TIDAL
FLOODING WILL CONTINUE TO SEE WATER BUILDUP WHICH WILL OCCUR DURING
THE HIGHER HIGH TIDE OVER THE NEXT COUPLE OF DAYS.

&&

.LONG TERM...TUESDAY THROUGH FRIDAY...WEAK SURFACE TO MIDDLE LEVEL
RIDGING WILL SET UP OVER AND NORTH OF THE KEYS FOR THE BALANCE OF
THE WEEK. NEVERTHELESS THE LOWER TO MID TROPOSPHERE WILL REMAIN
QUITE MOIST AND BACKING LOWER TO MID TROPOSPHERIC WINDS WILL STILL
BE MORE FAVORABLE FOR MESOSCALE CLOUD LINES...AND SHOWERS AND
THUNDERSTORMS. FOR NOW WILL MAINTAIN LOW CHANCES FOR POPS AS WE
ENTER THE CLIMATOLOGICAL LAST FULL MONTH OF THE WET SEASON.

&&

.MARINE...GENTLE EAST TO SOUTHEAST WINDS WILL CONTINUE TODAY AND
TONIGHT. WINDS WILL INCREASE A BIT MORE AND SEAS WILL BUILD IN
RESPONSE TO LOWER PRESSURE MOVING BY TO THE WEST OF THE KEY BETWEEN
SUNDAY AND MONDAY NIGHT. MODERATE BREEZES WILL BE LIKELY ACROSS A
GOOD PORTION OF THE WATERS...HOWEVER...MODERATE TO FRESH OR EVEN
FRESH BREEZES MAY DEVELOP ACROSS THE FLORIDA STRAITS AND OFFSHORE
GULF WATERS IN RESPONSE TO AN INCREASED GRADIENT. NOT ENOUGH
CONFIDENCE YET FOR THE STRONGER WINDS TO INCLUDE CAUTIONARY WORDING
YET FOR THESE PERIODS SO WILL NEED TO MONITOR MORE CLOSELY. MARINERS
SHOULD FOLLOW THE MARINE FORECAST MORE CLOSELY SUNDAY THRU MONDAY IF
THEY HAVE PLANS TO VENTURE OUT. ANY ELEVATED SEAS ON MONDAY NIGHT
WOULD LET DOWN APPRECIABLY BY TUESDAY.

&&

.AVIATION...UNTIL 00Z/27TH...OUTSIDE OF A BRIEF MVFR ENCOUNTER...VFR
CONDITIONS WILL PREDOMINATE AT THE KEY WEST AND MARATHON TERMINALS.
EAST TO SOUTHEAST WINDS OF 10 KNOTS OR LESS CAN BE EXPECTED AT THE
ISLAND AIRPORTS.

&&

.PRELIMINARY POINT TEMPS/POPS...
KEY WEST  88  80  88  82 / 30 30 30 30
MARATHON  90  80  90  82 / 30 30 30 30

&&

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

PUBLIC/MARINE.........FUTTERMAN
AVIATION/NOWCASTS.....APA

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HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE KEY WEST FL
529 AM EDT FRI SEP 25 2015

FLZ076>078-GMZ031>035-042>044-052>055-072>075-261000-
MONROE UPPER KEYS-MONROE MIDDLE KEYS-MONROE LOWER KEYS-
FLORIDA BAY INCLUDING BLACKWATER SOUND, BUTTONWOOD SOUND, AND
BARNES SOUND-
BAYSIDE AND GULFSIDE FROM CRAIG KEY TO WEST END OF SEVEN MILE
BRIDGE-
GULF WATERS FROM EAST CAPE SABLE TO CHOKOLOSKEE 20 TO 60 NM OUT
AND BEYOND 5 FATHOMS-
GULF OF MEXICO INCLUDING DRY TORTUGAS AND REBECCA SHOAL CHANNEL-
GULF OF MEXICO FROM WEST END OF SEVEN MILE BRIDGE TO HALFMOON
SHOAL OUT TO 5 FATHOMS-
HAWK CHANNEL FROM OCEAN REEF TO CRAIG KEY OUT TO THE REEF-
HAWK CHANNEL FROM CRAIG KEY TO WEST END OF SEVEN MILE BRIDGE OUT
TO THE REEF-
HAWK CHANNEL FROM WEST END OF SEVEN MILE BRIDGE TO HALFMOON SHOAL
OUT TO THE REEF-
STRAITS OF FLORIDA FROM OCEAN REEF TO CRAIG KEY OUT 20 NM-
STRAITS OF FLORIDA FROM CRAIG KEY TO WEST END OF SEVEN MILE
BRIDGE OUT 20 NM-
STRAITS OF FLORIDA FROM WEST END OF SEVEN MILE BRIDGE TO SOUTH OF
HALFMOON SHOAL OUT 20 NM-
STRAITS OF FLORIDA FROM HALFMOON SHOAL TO 20 NM WEST OF DRY
TORTUGAS OUT 20 NM-
STRAITS OF FLORIDA FROM OCEAN REEF TO CRAIG KEY 20 TO 60 NM OUT-
STRAITS OF FLORIDA FROM CRAIG KEY TO WEST END OF SEVEN MILE
BRIDGE 20 TO 60 NM OUT-
STRAITS OF FLORIDA FROM WEST END OF SEVEN MILE BRIDGE TO SOUTH OF
HALFMOON SHOAL 20 TO 60 NM OUT-
STRAITS OF FLORIDA FROM HALFMOON SHOAL TO 20 NM WEST OF DRY
TORTUGAS 20 TO 60 NM OUT-
529 AM EDT FRI SEP 25 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE FLORIDA KEYS AND
ADJACENT COASTAL WATERS.

.DAY ONE...TODAY AND TONIGHT

MINOR COASTAL FLOODING IS EXPECTED THIS MORNING IN LOW LYING AREAS
ACROSS THE FLORIDA KEYS.

SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS THE FLORIDA KEYS AND
ADJACENT COASTAL WATERS. THE PRIMARY THUNDERSTORM HAZARD WILL BE
LIGHTNING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

MINOR COASTAL FLOODING IS POSSIBLE AGAIN IN LOW LYING AREAS
THROUGHOUT THE KEYS ISLAND CHAIN SATURDAY THROUGH TUESDAY.

SCATTERED THUNDERSTORMS ARE EXPECTED ACROSS THE FLORIDA KEYS AND
ADJACENT COASTAL WATERS. THE PRIMARY THUNDERSTORM HAZARD WILL BE
LIGHTNING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED.

FUTTERMAN