734
FXUS62 KKEY 301441
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1041 AM EDT TUE JUN 30 2026
..NEW DISCUSSION, MARINE, AVIATION
KEY MESSAGES
- CONDITIONS ARE FAVORABLE TODAY FOR CLOUD LINE DEVELOPMENT OVER,
OR ADJACENT TO, THE FLORIDA KEYS. CLOUD LINE DEVELOPMENT WILL
CARRY THE RISK OF WATERSPOUTS.
- SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH THE MIDDLE OF THE WEEK.
- LIGHT TO GENTLE EAST TO SOUTHEASTERLY BREEZES WILL OCCASIONALLY
BECOME VARIABLE OVER THE NEXT COUPLE OF DAYS.
DISCUSSION
ISSUED AT 1041 AM EDT TUE JUN 30 2026
OVERNIGHT CONVECTION QUICKLY SIMMERED DOWN SHORTLY AFTER SUNRISE
AND WE ARE LEFT WITH A FEW VERY ISOLATED SHOWERS ACROSS THE
STRAITS OF FLORIDA. THIS LULL, HOWEVER, IS A DECEPTIVE LULL. THIS
IS PRIMARILY DUE TO A FRONTAL BOUNDARY THAT IS SLOWLY PUSHING
SOUTH ACROSS THE SOUTHEAST U.S. AND INTO THE SUNSHINE STATE. AS IT
HAS MOVED SOUTHWARD, IT HAS FLATTENED AND WEAKENED THE WESTERN
PERIPHERY OF A RIDGE THAT IS CENTERED OUT ACROSS THE ATLANTIC.
THIS IN TURN IS RESULTING IN WINDS ACTIVELY BECOMING LIGHT AND
VARIABLE. MEANWHILE, BETWEEN 925-700 MB, A LOW-LEVEL RIDGE REMAINS
IN PLACE. THIS FEATURE IS PROVIDING A NORTHEAST TO EAST WIND JUST
ABOVE THE BOUNDARY LAYER. THIS IS POTENTIALLY SETTING UP FOR A
CLOUD LINE TO DEVELOP ACROSS THE KEYS DURING THE LATE MORNING AND
AFTERNOON HOURS. THE ONLY CAVEAT IS THAT WE'RE DRY ABOVE THE
BOUNDARY LAYER. THIS MEANS AS CONVECTION TRIES TO BECOME MORE
VERTICAL IT WILL HAVE TO CONTEND WITH THIS DRIER LAYER.
IF ENOUGH LOWER LEVEL MOISTURE IS ABLE TO BE LIFTED UP, WE COULD
SEE A WELL-DEVELOPED CLOUD LINE TODAY. THE MAIN RISK WILL BE THE
POTENTIAL FOR WATERSPOUTS TO DEVELOP. A WATERSPOUT WOULD MOST
LIKELY APPEAR BENEATH A DARK, FLAT BOTTOM OF A BUILDING CUMULUS
LINE, JUST AT THE HINT OF RAIN. IF YOU SEE A WATERSPOUT, STAY
AWAY, AND CALL IN THE REPORT TO YOUR FLORIDA KEYS NATIONAL WEATHER
SERVICE, AT 3 0 5 2 9 5 1 3 1 6 EXTENSION 3. IF YOU SEE A SPOUT,
GIVE US A SHOUT! WE'D GREATLY APPRECIATE IT!
LASTLY, NO CHANGES WERE NEEDED OR MADE TO THIS FORECAST CYCLE.
MARINE
ISSUED AT 1041 AM EDT TUE JUN 30 2026
BREEZES WILL BE LIGHT AND VARIABLE FOR THE REMAINDER OF THE DAY
ACROSS A MAJORITY OF THE COASTAL WATERS. THE EXCEPTION WILL BE
ACROSS THE EXTREME SOUTHEAST GULF WATERS WHERE A LATE AFTERNOON
SURGE WILL DEVELOP ALONG THE WEST COAST OF FLORIDA AND SPILL IN
OUR WATERS. EXPECT BREEZES TO CLOCK AROUND FROM THE NORTHWEST AND
FRESHEN TO GENTLE BREEZES ACROSS THE SE GULF IN THE LATE
AFTERNOON. THEN TOWARDS AND JUST AFTER SUNSET, WE EXPECT A SURGE
TO COME OFF THE MAINLAND. THIS SECONDARY SURGE WILL EFFECT THE SE
GULF AS WELL AS THE ADJACENT WATERS NORTH OF THE ISLAND CHAIN.
EXPECT A QUICK FRESHENING OF GENTLE TO BRIEFLY MODERATE NORTH TO
NORTHEAST BREEZES DURING THE EVENING AND EARLY PORTIONS OF THE
OVERNIGHT. BY THE LATE OVERNIGHT AND EARLY PRE-DAWN HOURS, BREEZES
WILL CLOCK AROUND BACK FROM THE EAST TO SOUTHEAST AND SLACKEN
APPRECIABLY ONCE AGAIN.
AVIATION
(15Z TAFS)
ISSUED AT 1041 AM EDT TUE JUN 30 2026
VFR CONDITIONS WILL CONTINUE IN THE SHORT-TERM. KEEPING AN EYE OUT
FOR A CLOUD LINE TO DEVELOP WITHIN THE NEXT COUPLE OF HOURS AND
PERSIST INTO THE EVENING. SHOULD A FULLY MATURED CLOUD LINE
DEVELOP, WE COULD SEE ISOLATED SHOWERS AND THUNDERSTORMS DEVELOP
OVER THE ISLAND TERMINALS. EXACT TIMING IS HIGHLY UNCERTAIN AT
THIS TIME AND WILL ADD MENTIONS OF VCSH/TS AS NEEDED IF CONDITIONS
EVOLVE.
PREV DISCUSSION
ISSUED AT 538 AM EDT TUE JUN 30 2026
AN AREA OF CONVERGENCE ACROSS OUR SOUTHEASTERN GULF WATERS KEPT
OUR KBYX RADAR BUSY DURING THIS OVERNIGHT SHIFT! A FEW HOURS AGO,
A LINE OF SHOWERS AND THUNDERSTORMS DEVELOPED JUST NORTH OF THE
LOWER KEYS, AND EXTENDED TO THE WEST SOUTHWEST PAST DRY TORTUGAS
NATIONAL PARK. WHILE THIS ACTIVITY OCCURRED FAR AWAY FROM ANY
OBSERVATION PLATFORMS, THE PRESENCE OF PERSISTENT POCKETS OF
LIGHTING SUGGEST THAT SOME OF THESE STORMS WERE ON THE STRONGER
SIDE OF THINGS. AS WE ARE TYPING OUT THIS DISCUSSION, MOST OF THIS
ACTIVITY HAS ALREADY WANED. HOWEVER, THERE ARE RESIDUAL SHOWERS
JUST EAST OF MARATHON, AND WELL AS IN THE VICINITY OF KEY LARGO.
AMPLIFIED RIDGING ACROSS THE EASTERN U.S. WILL NUDGE CLOSER TO
THE ATLANTIC COAST, BUT A SLOWLY-MOBING FRONTAL BOUNDARY DRAGGING
DOWN THE PENINSULA IS INDICATIVE OF AN AREA OF "WEAKNESS" IN THIS
RIDGE. THE FRONTAL BOUNDARY ITSELF DOESN'T MEAN MUCH FOR US HERE,
BUT SHOWERS AND THUNDERSTORMS OVER THE PENINSULA TODAY MAY PRODUCE
OUTFLOW BOUNDARIES THAT ENCROACH ON OUR WATERS, AND MAY TRIGGER
NEW ACTIVITY. IN ADDITION TO THIS, THE NEBULOUS FLOW IN THE LOWER
LEVELS COULD RESULT IN CLOUDLINE DEVELOPMENT LATER THIS
AFTERNOON. IF A CLOUDLINE DOES DEVELOP EITHER OVER, OR ADJACENT
TO, THE ISLAND CHAIN, THESE COULD LEAD TO LOCALIZED MODERATE
RAINFALL AND POSSIBLY A FEW WATERSPOUTS. CONSIDERING THESE
VARIABLES AT PLAY, WE WILL CONTINUE TO ADVERTISE A SLIGHT CHANCE
(20%) OF SHOWERS AND THUNDERSTORMS.
THE HEFTY RIDGING WILL ALSO ENCOURAGE TOASTY AND MUGGY CONDITIONS.
AFTERNOON HIGHS WILL REMAIN IN THE LOWER 90S WITH LITTLE RECOVERY
TO THE LOWER AND MID 80S OVERNIGHT. AS LONG AS SKIES CAN CLEAR OUT
FROM ANY AFTERNOON SHOWERS, THE LIGHT WIND FIELD WILL HELP TO
RADIATE OUR USUAL SUSPECTS (WE'RE LOOKING AT YOU, BIG PINE). EVEN
THOUGH MOST OF OUR AUTOMATED OBSERVATION SITES REMAINED WARM
OVERNIGHT WITH TEMPERATURES CURRENTLY READING IN THE LOWER TO MID
80S, BIG PINE KEY WAS ABLE TO HIT 77F JUST BEFORE 6 AM COURTESY OF
RADIATIONAL COOLING.
WITH THE RIDGING ANCHORED IN PLACE OVER THE EASTERN U.S. THE
GENERAL DAY TO DAY PATTERN SHOULD NOT SEE ANY MEANINGFUL CHANGES.
SOME GUIDANCE SUGGESTS THAT SOME MOISTURE INFLUXES WILL COME
THROUGH LATER THIS WEEK, AND THIS WILL LEAD TO AN INCREASE IN RAIN
AND THUNDERSTORM CHANCES. OVERALL, A VERY NORMAL SUMMERTIME
PATTERN IS IN PLACE.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 92 83 92 83 / 20 20 20 20
MARATHON 90 82 89 83 / 20 20 20 20
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...LIW
AVIATION/NOWCASTS....LIW
DATA ACQUISITION.....LIW
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