653
FXUS62 KKEY 151536
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1036 AM EST MON DEC 15 2025
..NEW DISCUSSION, MARINE, AVIATION, PREV DISCUSSION
KEY MESSAGES
-A LOW CHANCE OF RAIN (20 TO 30%) STILL EXISTS TODAY AS ACTIVITY
OVER THE LOCAL WATERS MAY GET CLOSE TO THE ISLAND CHAIN.
-SMALL CRAFT ADVISORIES REMAIN IN EFFECT AS A RECENT COLD FRONT
PASSAGE HAS FRESHENED OUR BREEZES.
-AS HIGH PRESSURE BUILDS IN OVER THE SECOND HALF OF THE WEEK,
MILD, MOSTLY DRY CONDITIONS WILL BE EXPECTED WITH GENTLE TO
MODERATE BREEZES.
DISCUSSION
ISSUED AT 1036 AM EST MON DEC 15 2025
THE MOST RECENT COLD FRONT HAS CERTAINLY MADE ITS PRESENCE KNOWN
THIS MORNING. THE FRONT PASSED THROUGH DURING THE EARLY MORNING
HOURS AND THE WINDS QUICKLY FOLLOWED. ALONG THE REEF WE ARE SEEING
20 TO 25 KNOTS WITH NEAR 20 KNOTS ACROSS THE FLORIDA BAY AND
GULFSIDE WATERS. KBYX RADAR SHOWED A FLURRY OF ACTIVITY EARLIER
THIS MORNING AS THE FRONT INITIALLY PUSHED THROUGH BUT COVERAGE
IS DWINDLING. THAT BEING SAID, WHERE THE CONVERGENCE IS STRONGEST,
I.E, THE EASTERN HALF OF THE STRAITS, SHOWERS CONTINUE TO WAX AND
WANE. GIVEN THE ORIENTATION OF THE STEERING FROM (FROM THE
NORTHEAST), A THREAT FOR SHOWERS WILL CONTINUE FOR THE ISLAND
CHAIN. HIGHEST CHANCES WILL BE IN THE UPPER KEYS GIVEN ITS
PROXIMITY TO THE CONVERGENCE ZONE. AS MOISTURE SPILLS FURTHER
DOWNSTREAM THE LOWER AND MIDDLE KEYS MAY SEE SOME ISOLATED
SHOWERS.
MINOR CHANGES WERE MADE TO THE GOING FORECAST. MAINLY TO ADJUST
POPS AND SPLIT OUT THE UPPER KEYS FROM THE REST OF THE ISLAND
CHAIN. FEEL THAT MODELS ARE BEING OVERLY AGGRESSIVE ON HOW MUCH
MOISTURE WILL PIVOT IN TODAY (AS IS THE CASE BEHIND COLD FRONTS).
GIVEN THAN WE ARE NOW POST-FRONTAL, THE MAIN SOURCE FOR LIFT WILL
HAVE TO COME ABOUT FROM WHERE MASS AND MOMENTUM CONVERGE THE
STRONGEST. WITH THAT SAID, KEPT LOW END CHANCE POPS (30 PERCENT)
FOR THE UPPER KEYS, WHILE LOWERING POPS TO 20 PERCENT FOR THE REST
OF THE KEYS. OTHERWISE, NO OTHER CHANGES. EXPECT WINDY CONDITIONS
TO PREVAIL WITH A MINOR LULL THIS AFTERNOON BUT RETURNING BACK TO
CURRENT STRENGTH BY THIS EVENING.
MARINE
ISSUED AT 1036 AM EST MON DEC 15 2025
NO CHANGES MADE TO THE GOING FORECAST. SMALL CRAFT ADVISORY
CONDITIONS WILL CONTINUE ACROSS ALL OF THE FLORIDA KEYS COASTAL
WATERS. WE COULD SEE A BRIEF AND MINOR LULL IN BREEZES ACROSS THE
WATERS NORTH OF THE ISLAND CHAIN AS THE DAYTIME HEATS UP THIS
AFTERNOON. HOWEVER, AS MENTIONED, IT WILL BE BRIEF AS BREEZES WILL
RETURN TO FRESH TO STRONG THIS EVENING AND CONTINUE OVERNIGHT.
SHOWER AND THUNDERSTORM CHANCES WILL BE GREATEST ACROSS THE
STRAITS OF FLORIDA AND EVEN THEN THEY MAY TEND TO FAVOR THE
EASTERN HALF OF THE WATERS THROUGH THE AFTERNOON.
AVIATION
(15Z TAFS)
ISSUED AT 1036 AM EST MON DEC 15 2025
VFR CONDITIONS RETURNED THIS MORNING FOR BOTH ISLAND TERMINALS.
WILL BE KEEPING AN EYE AS ADDITIONAL MOISTURE PIVOTS IN FROM THE
NORTHEAST THIS AFTERNOON. IT COULD BRING BRIEF MVFR CIGS,
ESPECIALLY FOR THE MTH TERMINAL. THEREFORE, WILL INSERT A TEMP TO
COVER THE NEXT SEVERAL HOURS. OTHERWISE, GUSTY NORTHEAST WINDS OF
20 TO 25 KNOTS WILL PREVAIL FOR BOTH EYW AND MTH.
PREV DISCUSSION
ISSUED AT 504 AM EST MON DEC 15 2025
WEATHER CONDITIONS HAVE BEEN MOSTLY QUIET DURING THIS OVERNIGHT
SHIFT, BUT OUR KBYX RADAR HAS BEEN DETECTING POCKETS OF SHOWERS TO
THE EAST AND SOUTHEAST OF THE UPPER KEYS. THE SHOWERS CLOSEST TO
THE KEYS HAVE BEEN FILTERING IN FROM THE AREA JUST OFFSHORE OF
MIAMI, BUT THE NEWEST DEVELOPMENT OVER THE FLORIDA STRAITS SEEMS
TO BE FORMING ALONG SOME KIND OF BOUNDARY. TEMPERATURES ARE IN THE
LOWER 70S, BUT FREQUENT WIND GUSTS NEAR 20 MPH HAVE MADE IT FEEL
A LITTLE CHILLIER THAN THE PAST COUPLE OF NIGHTS. GOES-19 IR
IMAGERY SHOWS PATCHY LOW LEVEL CLOUDS OVER SOME OF OUR MARINE
ZONES, BUT THE ISLAND CHAIN IS STILL EXPERIENCING CLEAR SKIES.
THIS IS GOOD NEWS FOR OUR WARM WEATHER LOVERS, BECAUSE THE MORNING
SUNSHINE MAY TAKE SOME OF THE EDGE OFF OF THE CHILL. HOWEVER,
CLOUD COVER MAY FILL IN AS SHOWERS INCREASE, SO EXPECT ON AND OFF
SUNSHINE THROUGHOUT TODAY.
THE MOST NOTABLE IMPACT FROM THIS COLD FRONT ON OUR SENSIBLE
WEATHER WILL BE IN OUR SURFACE WINDS. BOTH NAEFS AND ECMWF
PERCENTILES SUGGEST THAT LOW LEVEL WINDS ACROSS OUR FORECAST AREA
TODAY WILL BE CLOSE TO A CLIMATOLOGICAL MAXIMUM. THIS IS A SIGNAL
THAT SIMPLY TELLS US THE WINDS IN THE CURRENT FORECAST ARE MUCH
HIGHER THAN WHAT AN "AVERAGE" FORECAST WOULD HOLD FOR THIS TIME OF
YEAR. WHILE THIS DOESN'T OFFER AN INSIGHT TO JUST HOW HIGH THESE
WINDS WILL BE, IT DOES PROVIDE CONFIDENT THAT WE ARE LOOKING AT
BREEZY TO WINDY CONDITIONS TODAY.
AS THE PARENT TROUGH PIVOTS AND LIFTS OVER THE COMING DAYS,
BREEZES WILL START TO SLACKEN OVER THE COURSE OF THE SECOND HALF
OF THE WEEK. MEAN LAYER RIDGING WILL ENCOURAGE A NEW PUSH OF
MOISTURE, BUT GUIDANCE IS STRUGGLING TO DETERMINE JUST HOW
SUBSTANTIAL THIS MOISTURE WILL BE. GFS AND ECMWF ENSEMBLE MEMBERS
POINT TO SOME CHANCES FOR RAINFALL, BUT THE NBM HAS SINGLE DIGIT
POPS. WE LIKELY WON'T SEE THIS WIDE RANGE OF SOLUTIONS COME TO AN
AGREEMENT UNTIL WE CLEAR THIS COLD FRONT, SO WE'LL HAVE TO MONITOR
HOW GUIDANCE TRENDS OVER THE NEXT FEW DAYS.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 77 68 77 70 / 20 20 10 10
MARATHON 76 68 76 70 / 20 20 10 10
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...SMALL CRAFT ADVISORY FOR GMZ031>035-042>044-052>055-072>075.
PUBLIC/MARINE/FIRE...LIW
AVIATION/NOWCASTS....LIW
DATA ACQUISITION.....LIW
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