965
FXUS62 KKEY 301453
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1053 AM EDT WED SEP 30 2026
..NEW DISCUSSION, MARINE, AVIATION, PREV DISCUSSION
KEY MESSAGES
- MINOR TO MODERATE SALTWATER FLOODING OF LOW ELEVATION STREETS
AND LOTS IS LIKELY TO CONTINUE OVER THE NEXT FEW DAY OR SO DUE
TO KING TIDE. DON'T DRIVE THROUGH FLOODED ROADWAYS. BOATERS CAN
EXPECT LESS CLEARANCE UNDER FIXED BRIDGES.
- A COASTAL FLOOD ADVISORY IS IN EFFECT FOR ALL OF THE FLORIDA KEYS.
- A WET PATTERN IS EXPECTED FOR THE NEXT SEVERAL DAYS ACROSS THE
KEYS. THIS WILL MAINTAIN ABOVE NORMAL RAIN AND THUNDER CHANCES
THROUGH AT LEAST FRIDAY.
DISCUSSION
ISSUED AT 1050 AM EDT WED SEP 30 2026
ROUND ONE OF SHOWERS AND THUNDERSTORMS ALREADY SPREAD THROUGH THE
LOWER AND MIDDLE KEYS ACCOMPANIED BY WIND GUSTS AROUND 35 MPH AND
RAINFALL RANGING FROM AROUND ONE HALF TO ONE INCH. ALOFT, THE
MID-UPPER LEVEL TROUGH CONTINUES TO SHARPEN WITH MILD HEIGHT RISES
NOTED AT UPPER AIR STATIONS ON OTHER SIDE, WITH THE MEAN DEEP
LAYER RIDGE OVER THE WESTERN NORTH ATLANTIC NOT READY TO BUDGE AT
THIS TIME, AND SOME UPPER RIDGING AMPLIFYING OVER THE EXTREME
WESTERN GULF AS AN UPPER LOW TRANSITS EASTWARD OVER THE FOUR
CORNERS REGION. THIS WILL CONTINUE THE NORTHERLY TRANSPORT OF
TROPICAL MOISTURE FROM THE WESTERN CARIBBEAN WITH PRECIPITATION
WATER 2 TO 2.25 INCHES. THE MORNING SOUNDING FEATURED A NARROW
INVERTED-V THERMAL/MOISTURE PROFILE, WHICH WAS CERTAINLY ERASED IN
THE RECENT ROUND OF CONVECTION. THE POSITIONING OF THE LOWER
TROPOSPHERIC RIDGE AXIS FAVORS AN EAST TO SOUTHEAST FLOW THIS
AFTERNOON, AND WITH THE UPPER TROUGH POSITION PROMOTES A BROAD
VEERING PROFILE. WHILE TEMPORARILY STABILIZATION WILL FOLLOW THIS
MORNING'S CONVECTION, VARIOUS CAMS AND THE THINNING UPPER OVERCAST
WILL PROMOTE QUICK INCREASES IN THE SKINNY CONVECTIVE AVAILABLE
POTENTIAL ENERGY THIS AFTERNOON, WITH ADDITIONAL CONVECTIVE ROUNDS
EXPECTED FEATURING HEAVY DOWNPOURS. NO CHANGES TO THE PUBLIC
FORECASTS ARE ANTICIPATED AT THIS TIME.
MARINE
ISSUED AT 1050 AM EDT WED SEP 30 2026
THERE ARE NO WATCHES, WARNINGS, OR ADVISORIES IN EFFECT ACROSS
THE FLORIDA KEYS COASTAL WATERS AT THIS TIME. SQUALLY SHOWERS AND
THUNDERSTORMS HAD PASSED THROUGH THE LOWER AND MIDDLE KEYS COAST
WATERS EARLIER THIS MORNING, LEAVING WINDS TEMPORARILY LIGHT AND
CONFUSED. SEAS MEASURED AT SATAN SHOAL WERE RUNNING 3 FEET WITH A
4 SECOND PERIOD. FROM SYNOPSIS: A HIGH PRESSURE SYSTEM ALONG THE
EASTERN SEABOARD WILL SHIFT FURTHER OFFSHORE AND MERGE WITH AN
EXISTING HIGH PRESSURE ACROSS THE SUBTROPICAL ATLANTIC AND
SUBSEQUENTLY BUILD THROUGH THE REMAINDER OF THE WEEK. THIS WILL
PROMOTE FRESHENING BREEZES WITH AN INCREASING LIKELIHOOD OF
MODERATE TO FRESH BREEZES BEGINNING WEDNESDAY, CONTINUING THROUGH
LATE WEEK. THERE IS A GOOD CHANCE THAT MARINE CAUTIONS MAY BE
REQUIRED FOR PORTIONS OF KEYS WATERS AT THAT TIME, AND ADVISORIES
CANNOT BE RULED OUT. IN ADDITION, A VERY WET PATTERN WILL REMAIN
ACROSS THE KEYS OVER THE NEXT FEW DAYS, RESULTING IN PERIODS OF
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS.
AVIATION
(15Z TAFS)
ISSUED AT 1050 AM EDT WED SEP 30 2026
WHILE VFR CONDITIONS WILL PREVAIL AT BOTH EYW AND MTH, BATCHES OF
SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCASIONALLY PUSH THROUGH
IN THE VICINITY OF THE TERMINALS. CONFIDENCE IS QUITE LOW IN TERMS
OF TIMING AND COULD REALLY OCCUR AT ANY TIME THROUGHOUT THE TAF
PERIOD, WITH SUB-VFR CEILINGS AND VISIBILITIES AS WELL AS CROSSWIND
GUSTS POSSIBLE WITH ANY STRONGER STORM. HAVE INCLUDED A GENERAL
MENTION OF VCSH AT EYW AND A PREVAILING PERIOD OF SHRA FOR NOW AT
MTH, ALONG WITH A PROB30 GROUP. THIS WILL BE REEVALUATED WITH THE
18Z TAF ISSUANCE.
PREV DISCUSSION
ISSUED AT 417 AM EDT WED SEP 30 2026
THE FLORIDA KEYS ARE IN A MOMENTARY LULL WITH THE KBYX RADAR
SURPRISINGLY QUIET ALL ACROSS OUR CWA. NEAREST AREA OF CONVECTION
IS MOVING OFF THE NORTH COAST OF CUBA AND BEGINNING TO ENTER OPEN
WATERS. TIME WILL TELL IF THIS ACTIVITY LINGERS INTO OUR WATERS.
OTHERWISE, WE ARE IN THE THICK OF IT SO TO SPEAK. AN UPPER LEVEL
TROUGH LIES TO OUR WEST ACROSS THE CENTRAL GULF BASIN, EXTENDING
WELL INTO THE YUCATAN PENINSULA. THIS HAS PLACED THE KEYS UNDER A
DEEP SOUTHERLY FLOW THAT CONTINUES TO TRANSPORT TROPICAL MOISTURE
FROM THE WESTERN CARIBBEAN. IN FACT, WE'RE MONITORING THE NEARLY
WEST TO EAST LINE OF CONVECTION THAT HAS BEEN STEADILY MOVING
NORTH AND IS CURRENTLY REACHING CUBA. THIS LINE IS ON PACE TO
REACH THE KEYS BETWEEN 0900-1200 TODAY. GIVEN THIS TRAJECTORY
PLUS THE DEEP TROPICAL MOISTURE INFLUX AND THE PRESENCE OF THE
NEARBY UPPER LEVEL TROUGH, LIKELY POPS CAN BE EXPECTED TODAY. IN
ADDITION, WE CONTINUE TO BE UNDER THE INFLUENCE OF KING TIDES,
THEREFORE, SHOULD HEAVY RAIN COINCIDE WITH TIMES OF HIGH TIDE, WE
COULD SEE BRIEF PERIODS OF ENHANCED FLOODING.
MEANWHILE, TO OUR NORTH, A SURFACE HIGH PRESSURE SITS ALONG THE
EASTERN SEABOARD. THIS FEATURE WILL SLOWLY MEANDER OFFSHORE
THROUGHOUT THE DAY AND MERGE WITH AN EXISTING ATLANTIC RIDGE AND
SUBSEQUENTLY BUILD. THIS WILL LEAD TO FRESHENING EAST TO SOUTHEAST
BREEZES ACROSS THE REGION. IT IS BECOMING INCREASINGLY LIKELY THAT
WE WILL SEE A PERIOD OF BREEZY CONDITIONS WITH MARINE CAUTION
HEADLINES LIKELY ACROSS THE SURROUNDING COASTAL WATERS. THERE IS A
CHANCE THAT GIVEN THE EARLY NATURE OF THIS BUILDING HIGH THAT
MODELS MAY BE SLIGHTLY UNDERPLAYING THE STRENGTH OF THE WINDS.
NONETHELESS, WE CAN EXPECT A PERIOD OF MODERATE TO FRESH BREEZES
AT LEAST THROUGH FRIDAY. THEREAFTER, THE RIDGE WILL GRADUALLY EASE
AND ALLOW FOR BREEZES TO SLOWLY SLACKEN BACK TO GENTLE TO
OCCASIONALLY MODERATE OVER THE WEEKEND. AS THE HIGH EASES, WE
SHOULD SEE RAIN CHANCES RETURN CLOSER TO NORMAL FOR WHAT WILL BE
THE FIRST WEEKEND OF OCTOBER.
KEY WATCHES/WARNINGS/ADVISORIES
FL...COASTAL FLOOD ADVISORY FOR FLZ076>078.
GM...NONE.
PUBLIC/MARINE/FIRE...JR
AVIATION/NOWCASTS....BT
DATA ACQUISITION.....BT
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