847
FXUS62 KKEY 011001
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
601 AM EDT WED JUL 1 2026
..NEW DISCUSSION, MARINE, AVIATION
KEY MESSAGES
- CONDITIONS WILL BE FAVORABLE FOR ISLAND CLOUD LINE FORMATION
NEAR PORTIONS OF THE FLORIDA KEYS TODAY. CLOUD LINE DEVELOPMENT
WILL CARRY THE RISK OF WATERSPOUTS.
- A CHANCE OF SHOWERS WITH A SLIGHT CHANCE OF THUNDERSTORMS WILL
PERSIST THROUGH TONIGHT.
- LIGHT TO GENTLE EAST TO SOUTHEASTERLY BREEZES WILL OCCASIONALLY
BECOME VARIABLE THROUGH WEDNESDAY EVENING.
DISCUSSION
ISSUED AT 600 AM EDT WED JUL 1 2026
WEATHER CONDITIONS DURING THE OVERNIGHT SHIFT HAVE REMAINED MOSTLY
UNREMARKABLE OUTSIDE OF A FEW ISOLATED SHOWERS AND THUNDERSTORMS,
MAINLY ACROSS THE FLORIDA STRAITS. ONLY A HANDFUL OF LIGHTNING
STRIKES WERE DETECTED BY THE GOES-19 SATELLITE, ESPECIALLY BEFORE
MIDNIGHT. ALONG THE ISLAND CHAIN, TEMPERATURES HAVE SAT IN THE
LOWER TO MID 80S WITH DEW POINTS IN THE MID TO UPPER 70S. THE
EXCEPTION, SIMILAR TO YESTERDAY MORNING, IS ON BIG PINE KEY WHERE
RADIATIONAL COOLING BROUGHT TEMPERATURES DOWN TO THE UPPER 70S.
AMPLIFIED RIDGING ACROSS THE EASTERN U.S., CENTERED SOMEWHERE
AROUND WESTERN VIRGINIA, WILL CONTINUE TO KEEP SENSIBLE WEATHER
MOSTLY BENIGN. FORECASTING WHEN, AND WHERE, SHOWERS AND
THUNDERSTORMS WILL POP UP FEELS ALMOST IMPOSSIBLE, BECAUSE WE HAVE
TWO DIFFERENT MECHANISMS WE ARE DEPENDING ON THE TRIGGER ACTIVITY.
THE LIGHT AND VARIABLE WIND FIELD OPENS THE DOOR FOR POSSIBLE
CLOUD LINE DEVELOPMENT EITHER OVER, OR ADJACENT TO, PORTIONS OF
THE ISLAND CHAIN DURING THE AFTERNOON. THIS WOULD RESULT IN VERY
LOCALIZED POCKETS OF SHOWERS AND THUNDERSTORMS, AS WELL AS A
POSSIBILITY FOR WATERSPOUTS. THE SECOND TRIGGER FOR ACTIVITY COMES
FROM THE AFTERNOON THUNDERSTORMS OVER THE MAINLAND THAT STEM FROM
SEA BREEZE CONVERGENCE. THIS ACTIVITY CAN EITHER DRIFT INTO OUR
FORECAST AREA, OR OUTFLOW BOUNDARIES CAN COLLIDE AND TRIGGER NEW
ACTIVITY, WHICH IS ESSENTIALLY WHAT WE SAW YESTERDAY. ALL OF THIS
IS TO SAY THAT THE INGREDIENTS FOR SOME SHOWERS AND THUNDERSTORMS
ARE THERE AS IS PRETTY TYPICAL FOR JULY IN FLORIDA. THE QUESTION
IS SIMPLY WHERE AND WHEN DOES THIS ACTIVITY POP UP.
AFTER TODAY, THE RIDGING WILL NUDGE TOWARD THE ATLANTIC
COASTLINE. WHILE THIS HAPPENS, A PULSE OR TWO OF VORTICITY WILL
UNDERCUT THE RIDGE AND CLIP THE AREA, WHICH WILL NURTURE AN
ENVIRONMENT CONDUCIVE TO AN INCREASE IN SHOWERS AND THUNDERSTORMS.
THIS ISN'T A PATTERN EVOLUTION THAT WOULD FAVOR A WIDESPREAD
WASHOUT OVER THE HOLIDAY WEEKEND, BUT BOTH DETERMINISTIC AND
ENSEMBLE GUIDANCE SHOW SOME DEEPER MOISTURE AND BETTER INSTABILITY
THAT WOULD TRANSLATE TO AN INCREASE IN THE AMOUNT OF ACTIVITY
SOMEWHERE WITHIN THE BOUNDARY OF OUR CWA. PROBABILISTIC GUIDANCE
FAVORS ACTIVITY DURING THE DAY ON INDEPENDENCE DAY, AND IF WE CAN
WORK OVER THE ENVIRONMENT, THAT MAY GIVE US A WINDOW OF DRIER
CONDITIONS FOR ANYONE CELEBRATING OUTDOORS. HOWEVER, THAT
HYPERLOCAL SCALE IS UNREALISTIC TO TRY AND FORECAST FOR THREE DAYS
OUT, SO THE PATTERN WILL CONTINUE TO BE MONITORED.
MARINE
ISSUED AT 600 AM EDT WED JUL 1 2026
THERE ARE NO WATCHES, WARNINGS, OR ADVISORIES IN EFFECT FOR THE
FLORIDA KEYS WATERS. FROM SYNOPSIS, GENERALLY EAST TO SOUTHEAST
BREEZES WILL BECOME VARIABLE AT TIMES TODAY OUTSIDE OF ANY SHOWERS
OR THUNDERSTORMS THAT MAY DEVELOPMENT. ACTIVE WEATHER WILL DEPEND
ON IF, OR WHEN, A CLOUD LINE CAN DEVELOP ALONG OR NEAR THE ISLAND
CHAIN. CLOUD LINE DEVELOPMENT WILL ALSO INCREASE THE CHANCES FOR
WATERSPOUTS. AFTERNOON SHOWERS AND THUNDERSTORMS OVER THE MAINLAND
MAY ALSO DRIFT INTO OUR LOCAL WATERS. HIGH PRESSURE GRADUALLY
BUILDS BACK ACROSS THE AREA THURSDAY WITH PEAKS AND LULLS IN THE
WIND FIELD RESUMING AT THAT TIME.
AVIATION
(06Z TAFS)
ISSUED AT 600 AM EDT WED JUL 1 2026
WHILE VFR CONDITIONS WILL PREVAIL AT BOTH ISLAND TERMINALS, THERE
IS A LOW CHANCE, AROUND 20 PERCENT, OF SHOWERS AND THUNDERSTORMS
AFTER 15Z. OPTING TO LEAVE A BROADBRUSHED VCSH IN THE TAFS, AND
WILL TRY TO NARROW THE TIMING ONCE SHOWERS INITIATE. IF ANY OF
THIS ACTIVITY MOVES OVER EITHER TERMINAL, THE MOST LIKELY IMPACT
WILL BE LOWERED CIGS. SURFACE WINDS WILL GENERALLY BE LIGHT AND
VARIABLE, BUT ARE EXPECTED TO RESUME A UNIFORM SOUTHEASTERLY
DIRECTION AT 5 TO 10 KNOTS.
OF NOTE IN KEYS WEATHER HISTORY
ON THIS DAY IN 1957, THE KEY WEST WEATHER BUREAU MOVED TO THE
AIRPORT.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 92 83 92 83 / 20 30 20 10
MARATHON 89 82 89 83 / 20 20 20 10
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...DP
AVIATION/NOWCASTS....DP
DATA ACQUISITION.....BT/RG
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