665
FXUS62 KKEY 121508
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1108 AM EDT FRI JUN 12 2026
..NEW DISCUSSION, MARINE, AVIATION
KEY MESSAGES
- ISLAND CLOUD LINE FORMATION WILL BE POSSIBLE IN THE LATE MORNING
OR AFTERNOON HOURS THROUGH THE WEEKEND.
- WATERSPOUTS WILL BE POSSIBLE WITH ANY DEVELOPING ISLAND CLOUD
LINE.
- CONDITIONS WILL REMAIN SEASONABLY WARM AND MUGGY, WITH HEAT
INDICES APPROACHING NEAR 100F EACH AFTERNOON THROUGH EARLY NEXT
WEEK.
DISCUSSION
ISSUED AT 1107 AM EDT FRI JUN 12 2026
THE 12Z MORNING SOUNDING AT KEY SAMPLED SEVERAL DISCERNIBLE FEATURES.
A COMPOSITE ANALYSIS OF THESE FEATURES WILL BE THE PRIMARY SOURCE
FOR THIS MORNING'S UPDATE DISCUSSION. IN THE LOW LEVELS, 0-3 KM
MEAN WINDS WERE LIGHT OUT OF THE NORTHEAST TO EAST. THIS IS IN
RESPONSE TO A WEAK, ELONGATED SURFACE HIGH PRESSURE SYSTEM
EXTENDING FROM THE SOUTHEAST EASTWARD TO THE WESTERN NORTH
ATLANTIC. THE SOUNDING DEPICTED SUBSTANTIAL DRY AIR IN THE 900-700
MB ISOBARIC LAYER, CONSISTENT WITH A DECAYING SAHARAN AIR LAYER
(SAL) THAT HAS ADVECTED ACROSS THE FLORIDA KEYS AND THE ADJACENT
MARINE ZONE. FINALLY, ALOFT, THE SOUNDING DEPICTED A GENERALLY
SATURATED LAYER EXTENDING FROM AROUND 600 MB UPWARD TO 550 MB.
THIS IS CONSISTENT WITH THE OUTSKIRTS OF A QUASISTATIONARY CENTRAL
AMERICAN GYRE (CAG) CENTERED IN THE VICINITY OF THE BAY OF
CAMPECHE.
FOR THIS AFTERNOON, THE LIGHT NORTHEAST TO EAST BREEZES WOULD
NORMALLY SUPPORT POTENTIAL ISLAND CLOUD LINE FORMATION. IN FACT,
OUR IN-HOUSE WATERSPOUT INDEX DERIVED FROM THE 12Z KEY SOUNDING IS
AT 18%, SUGGESTING NEARLY A ONE IN FIVE CHANCE FOR AN OBSERVED
WATERSPOUT TO BE REPORTED IN THE FLORIDA KEYS. HOWEVER, ANY CLOUD
LINE WOULD FIGHT THE DRY SAL. FURTHERMORE, THE CIRRUS MAY LIMIT
SURFACE-BASED INSTABILITY OVER THE ISLAND CHAIN. GIVEN ALL THIS,
SLIGHT LEVEL RAIN AND THUNDER CHANCES (10-20%) STILL SEEMS ON
TRACK FOR TODAY. NO CHANCES PROPOSED.
MARINE
ISSUED AT 1107 AM EDT FRI JUN 12 2026
NO WATCHES, WARNINGS, OR ADVISORIES ARE IN EFFECT FOR THE FLORIDA
KEYS COASTAL WATERS. FROM SYNOPSIS, ELONGATED HIGH PRESSURE
EXTENDING FROM THE SOUTHEAST EASTWARD TO THE WESTERN NORTH
ATLANTIC WILL SUPPORT LIGHT TO GENTLE EAST TO SOUTHEAST BREEZES
TODAY THROUGH SATURDAY, GRADUALLY VEERING TO THE SOUTHEAST TO
SOUTH FOR SUNDAY THROUGH EARLY NEXT WEEK. SHOWER COVERAGE ACROSS
THE FLORIDA KEYS COASTAL WATERS WILL REMAIN LOW WHILE A LAYER OF
DRY AIR LINGERS IN THE LOWER ATMOSPHERE.
AVIATION
(15Z TAFS)
ISSUED AT 1107 AM EDT FRI JUN 12 2026
VFR CONDITIONS WILL PREVAIL ACROSS THE TERMINALS THROUGH 12Z
SATURDAY MORNING. THE BEST CHANCES FOR AN ISOLATED SHOWER OR
THUNDERSTORM WILL BE ASSOCIATED WITH POSSIBLE ISLAND CLOUD LINE
FORMATION THIS AFTERNOON. NEAR-SURFACE WINDS WILL LIGHT, GENERALLY
OUT OF THE EAST TO SOUTHEAST, OCCASIONALLY BACKING TO THE
NORTHEAST TO EAST.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 89 81 89 81 / 20 10 20 10
MARATHON 89 81 90 81 / 20 10 20 10
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...BT
AVIATION/NOWCASTS....BT
DATA ACQUISITION.....BT
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