252
FXUS62 KKEY 301040
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
640 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 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.
MARINE
ISSUED AT 538 AM EDT TUE JUN 30 2026
THERE ARE NO WATCHES, WARNINGS, OR ADVISORIES IN EFFECT FOR THE
FLORIDA KEYS LOCAL WATERS. FROM SYNOPSIS, A FRONTAL BOUNDARY WILL
CONTINUE TO NUDGE TOWARD CENTRAL FLORIDA WHERE IT WILL LINGER FOR
THE REST OF THE DAY. THIS WILL LEAD TO FURTHER WEAKENING OF A
BROAD HIGH STREWN ACROSS THE REGION AND ALLOW FOR LIGHT AND
VARIABLE BREEZES. CONDITIONS ARE FAVORABLE FOR A CLOUD LINE TO
DEVELOP OVER, OR ACROSS THE WATERS ADJACENT TO, THE FLORIDA KEYS
ON TUESDAY. THIS MAY SUPPORT THE DEVELOPMENT OF WATERSPOUTS.
AVIATION
(06Z TAFS)
ISSUED AT 538 AM EDT TUE JUN 30 2026
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. HOWEVER,
CONDITIONS ARE FAVORABLE FOR CLOUD LINE DEVELOPMENT EITHER ALONG
,OR ADJACENT TO, THE ISLAND CHAIN. THIS ACTIVITY WOULD BE SHORT
LIVED, BUT COULD LEAD TO PERIODS OF LOWERED FLIGHT CATEGORIES
DEPENDING ON THE INTENSITY OF THE CLOUD LINE. OPTING TO KEEP THE
TAFS FREE OF IMPACTS UNTIL A LINE ACTUALLY DEVELOPS. OTHERWISE,
EAST TO SOUTHEAST SURFACE WINDS OF 5 TO 10 KNOTS WILL BECOME LIGHT
AND VARIABLE, BUT CROSSWIND CONCERNS ARE LOW.
OF NOTE IN KEYS WEATHER HISTORY
MAY & JUNE 2010 COUPLE TOGETHER TO MARK THE WARMEST MAY/JUNE ON RECORD
FOR KEY WEST, WITH AN AVERAGE TEMPERATURE OF 84.0F, FOLLOWING THE COLDEST
JANUARY/FEBRUARY/MARCH ON RECORD FOR KEY WEST. FOR MARATHON, MAY
& JUNE 2019 COUPLE TOGETHER TO MARK THE WARMEST MAY/JUNE ON RECORD,
WITH AN AVERAGE TEMPERATURE OF 86.9F. TEMPERATURE RECORDS FOR KEY
WEST DATE BACK TO 1872, AND FOR MARATHON DATE BACK TO 1951.
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...DP
AVIATION/NOWCASTS....DP
DATA ACQUISITION.....DR
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