508
FXUS62 KKEY 140832
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
432 AM EDT MON JUL 14 2025
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 430 AM EDT MON JUL 14 2025
KBYX RADAR HAS BEEN ACTIVE OVERNIGHT. MULTIPLE MESOSCALE
BOUNDARIES CONTINUE TO MEANDER ABOUT THE FLORIDA KEYS. THESE
BOUNDARIES HAVE BEEN RESPONSIBLE FOR WAXING AND WANING ISOLATED
SHOWERS AND THUNDERSTORMS THROUGHOUT THE OVERNIGHT HOURS. MOST OF
THE ACTIVITY HAS REMAINED OUT OVER THE STRAITS OF FLORIDA WITH THE
MOST RECENT ACTIVITY BEING A FAIRLY ROBUST THUNDERSTORM WHICH
DEVELOPED RIGHT OVER BIG PINE KEY AND NO NAME KEY. THIS CELL
PROMPTED A MARINE WEATHER STATEMENT FOR WIND GUSTS TO NEAR 30
KNOTS THROUGH AROUND 400 AM EARLIER THIS MORNING. GOES EAST
NIGHTTIME MICROPHYSICS IMAGERY SHOWS CUMULUS CONGESTUS CLOUDS
ALONG WITH SOME HIGH LEVEL CIRRUS THROUGHOUT THE AREA. THE ONLY
CUMULONIMBUS IS ASSOCIATED WITH THE THUNDERSTORM OVER BIG PINE
KEY. MRMS DATA SHOWS ESTIMATED RAINFALL AMOUNTS OF A HALF TO ONE
INCH FOR BIG PINE KEY. TEMPERATURES ALONG THE ISLAND CHAIN ARE IN
THE LOWER 80S WITH DEW POINTS IN THE MID TO UPPER 70S. HOWEVER,
BIG PINE KEY HAS DROPPED TO A COOL 72 DEGREES WITH A DEW POINT OF
67 DEGREES AS A RESULT OF A THUNDERSTORM THAT RECENTLY AFFECTED
THE AREA. HIGH PRESSURE REMAINS OVER THE AREA WITH LOW PRESSURE
CENTERED OFF THE NORTH FLORIDA/GEORGIA COASTLINE. THE PRESSURE
GRADIENT BETWEEN THESE TWO SYSTEMS IS ACTUALLY RATHER WEAK WITH
ONLY A FEW MILLIBARS SEPARATING HIGH AND LOW PRESSURE. DUE TO
THIS, MARINE PLATFORMS AROUND THE KEYS ARE OBSERVING MAINLY
VARIABLE BREEZES OF 5 KNOTS OR LESS, ESPECIALLY OUTSIDE OF ANY
CONVECTION. ISLAND CHAIN COMMUNITIES ARE ALSO OBSERVING VARIABLE
BREEZES OF NEAR 5 MPH OR LESS.
FORECAST
TODAY THROUGH WEDNESDAY, THE FOCUS WILL MAINLY BE ON THE 30% AREA
FOR TROPICAL DEVELOPMENT WITHIN THE NEXT 7 DAYS THAT THE NHC-
NATIONAL HURRICANE CENTER HAS HIGHLIGHTED ACROSS THE NORTHERN
GULF. AT MOST, A WEAK AREA OF LOW PRESSURE IS EXPECTED TO CONTINUE
MEANDERING SLOWLY SOUTHWARD FROM OFF THE GEORGIA COASTLINE AND
THEN RETROGRADE BACK TO THE WEST THROUGH MID WEEK. AS A RESULT,
BOUTS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE INITIATED
EACH DAY AS THE SYSTEM SLOWLY MOVES THROUGH THE AREA. MOST OF THE
ACTIVITY THE KEYS COULD SEE MAY INITIALLY FORM ON THE MAINLAND AND
THEN DRIFT SOUTHWARD THROUGH THE KEYS. ANY STORMS WILL BE CAPABLE
OF PRODUCING STRONG GUSTY WINDS, LOCALLY HEAVY RAINFALL, AND
FREQUENT LIGHTNING. THE FORECAST WAS SPLIT FOR THE TODAY PERIOD
FOR THE UPPER KEYS (70%) AND THEN THE MIDDLE AND LOWER KEYS (50%).
CONFIDENCE REMAINS HIGHER IN THE UPPER KEYS BEING THE MORE
FAVORABLE REGION FOR SHOWERS AND THUNDERSTORMS TODAY AS STORMS
ROLL OFF THE MAINLAND. AS WE PROGRESS INTO TONIGHT, THE CHANCE FOR
RAIN GOES UP TO ABOUT THE SAME EVERYWHERE WITH 70% FOR THE ISLAND
CHAIN. THE WEATHER PREDICTION CENTER (WPC) HAS THE KEYS
HIGHLIGHTED IN A MARGINAL RISK (LEVEL 1 OUT OF 4) FOR THE TODAY
THROUGH TUESDAY TIME PERIOD.
A MORE TYPICAL SUMMER TIME PATTERN RETURNS FOR THE SECOND HALF OF
THE WEEK AND INTO THE WEEKEND. HIGH PRESSURE OVER THE ATLANTIC
BUILDS INTO FLORIDA BRINGING A RETURN TO THE EAST TO
SOUTHEASTERLIES AND MOISTURE UNDULATIONS AROUND THE WESTERN
PERIPHERY OF THE HIGH. AS A RESULT, EXPECT DECREASING RAIN CHANCES
WITH 40% FOR WEDNESDAY NIGHT AND THURSDAY BEFORE RAIN CHANCES
RETURN TO AROUND NORMAL FOR THE REMAINDER OF THE EXTENDED WHICH IS
NEAR 30%. ALSO, IT WILL FOR SURE BE SUMMER WITH HIGHS IN THE LOWER
90S AND OVERNIGHT LOWS IN THE LOWER 80S. HEAT INDEX VALUES ARE
EXPECTED TO RANGE FROM 102-107 DEGREES THROUGH THIS PERIOD WHICH
IS JUST UNDER HEAT ADVISORY CRITERIA. WE WILL CONTINUE TO MONITOR.
MARINE
ISSUED AT 430 AM EDT MON JUL 14 2025
THERE ARE CURRENTLY NO WATCHES, WARNINGS, OR ADVISORIES IN EFFECT
ACROSS THE FLORIDA KEYS COASTAL WATERS. FROM SYNOPSIS, WEAK LOW
PRESSURE TRIES TO DEVELOP IN THE VICINITY OF FLORIDA HEADING
THROUGH THE FIRST HALF OF THE WEEK. INITIALLY, THE KEYS WILL BE ON
THE SOUTHERN FRINGE IN A COL REGION RESULTING IN MAINLY VARIABLE
BREEZES THROUGH TONIGHT. AS THE WEAK LOW PRESSURE AREA SHIFTS TO
THE WEST AND HIGH PRESSURE BUILDS IN BEHIND, BREEZES WILL FRESHEN
BECOMING SOUTHEAST TO SOUTH AT FIRST, BEFORE BECOMING EAST TO
SOUTHEAST FOR MID TO LATE WEEK. ALSO, EXPECT INCREASING COVERAGE
OF SHOWERS AND THUNDERSTORMS THROUGH THE MIDDLE PART OF THE WEEK.
AVIATION
(06Z TAFS)
ISSUED AT 430 AM EDT MON JUL 14 2025
VFR CONDITIONS ARE EXPECTED TO LARGELY PREVAIL AT EYW AND MTH
THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE THE LIKELIHOOD OF
PASSING SHOWERS AND THUNDERSTORMS THROUGHOUT THE DAY PRODUCING
MVFR OR LOWER CONDITIONS , THOUGH TIMING AND COVERAGE CARRIES
ENOUGH UNCERTAINTY TO LEAVE MENTION OF THIS FOR LATER TAF
AMENDMENTS AND ROUTINE ISSUANCES. WINDS WILL REMAIN VARIABLE AT
NEAR 5 KNOTS. HIGHER GUSTS WILL BE POSSIBLE WITH PASSING SHOWER
AND THUNDERSTORM ACTIVITY.
CLIMATE
ON THIS DAY IN 2023, THE DAILY RECORD HIGH TEMPERATURE OF 98F AND
THE DAILY RECORD WARM LOW TEMPERATURE OF 86F WERE RECORDED AT
MARATHON. TEMPERATURE RECORDS FOR MARATHON DATE BACK TO 1950.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 88 78 85 80 / 50 70 80 60
MARATHON 90 76 86 80 / 50 70 80 60
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...MJV
AVIATION/NOWCASTS....MC
DATA ACQUISITION.....MC
VISIT US ON THE WEB AT WEATHER.GOV/KEY
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSKEYWEST
WWW.TWITTER.COM/NWSKEYWEST
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page