308
FXUS62 KKEY 291858
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
258 PM EDT SUN JUN 29 2025
..NEW AVIATION AND MARINE
AVIATION
(18Z TAFS)
ISSUED AT 243 PM EDT SUN JUN 29 2025
DESPITE BOUTS OF BKN180 CEILINGS, VFR CONDITIONS WILL PREVAIL AT
BOTH ISLAND TERMINALS THROUGH 18Z MONDAY AFTERNOON. SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE, MAINLY AFTER
12Z MONDAY, ALTHOUGH CONFIDENCE IN INITIATION TIME AND EVOLUTION
BARS INCLUSION IN THE TAFS AT THIS TIME. NEAR- SURFACE WINDS WILL
REMAIN OUT OF THE EAST TO SOUTHEAST AT 9 TO 11 KNOTS
MARINE
ISSUED AT 243 PM EDT SUN JUN 29 2025
NO WATCHES, WARNINGS, OR ADVISORIES ARE CURRENTLY IN EFFECT FOR
THE COASTAL WATERS OF THE FLORIDA KEYS. FROM SYNOPSIS, BROAD LOW-
LEVEL RIDGING WILL CONTINUE TO REBUILD OVER THE NORTH ATLANTIC AND
SUPPORT GENTLE TO MODERATE EAST TO SOUTHEASTERLY BREEZES ACROSS
FLORIDA KEYS COASTAL WATERS, VEERING TO THE SOUTHEAST TO SOUTH AND
MODESTLY SLACKENING THROUGHOUT THE WEEK. AN UPPER- LEVEL LOW EAST
OF THE BAHAMAS WILL SLIDE SLOWLY NORTHWESTWARD TOWARDS THE
FLORIDA EAST COAST EARLY THIS WEEK, SUPPORTING SLIGHTLY ENHANCED
RAIN AND THUNDER CHANCES. A RETURN TO NEAR- NORMAL RAIN AND
THUNDER CHANCES IS EXPECTED FOR WEDNESDAY THROUGH THE END OF THE
WORK WEEK.
PREV DISCUSSION
ISSUED AT 1136 AM EDT SUN JUN 29 2025
COMPOSITE REGIONAL SATELLITE ANALYSIS HIGHLIGHTS POCKETS OF LOW
CUMULUS CLOUDS STREAMING TOWARDS THE FLORIDA KEYS IN THE MEAN
BOUNDARY LAYER EAST TO SOUTHEASTERLIES. MEANWHILE, FURTHER ALOFT,
A PRETTY THICK DECK OF CIRRUS CLOUDS ARE DIVING SOUTHWESTWARD
ASSOCIATED WITH A TROPICAL UPPER TROPOSPHERIC TROUGH (TUTT) CELL
CENTERED EAST OF THE BAHAMAS. THE 12Z MORNING SOUNDING AT KEY
CONTINUED TO SAMPLE A WELL-DEFINED SAHARAN AIR LAYER (SAL)
SIGNATURE, WITH VERY DRY AIR EMBEDDED IN THE 500-900 MB ISOBARIC
LAYER. THE CIRRUS DECK IS DOING LITTLE TO HOLD TEMPERATURES IN
CHECK, WITH SURFACE OBSERVATIONS ALONG THE ISLAND CHAIN REPORTING
TEMPERATURES IN THE UPPER 80S ON THIS LATE JUNE MORNING. KBYX
RADAR IS VOID OF ANY METEOROLOGICAL ECHO RETURNS.
GIVEN THE IMMENSE SAL-INDUCED DRY AIR, AS WELL AS THE DENSE
CIRRUS DECK SATELLITE TRENDS AND UPSTREAM, ELECTED TO LOWER POPS
AND NUDGE SKY COVER UPWARD FOR THE FIRST PERIOD. OTHER THAN THAT,
NO CHANGES PROPOSED FOR THIS LATE MORNING UPDATE ITERATION.
200
FORECAST
ISSUED AT 440 AM EDT SUN JUN 29 2025
A QUIET START TO THE WEEKEND IS UNDERWAY FOR THE FLORIDA KEYS
THIS MORNING. KBYX RADAR IS CLEAR OF ANY PRECIPITABLE ECHOES AS
SHOWERS FROM YESTERDAY EVENING HAVE LONG SINCE DISPERSED. GOES-19
NIGHTTIME MICROPHYSICS RGB IMAGERY DEPICTS LINES OF SHALLOW
CUMULUS DRIFTING TOWARDS THE KEYS WITH SOME HIGH CIRRUS BUBBLING
IN FROM THE SOUTH. SENSIBLE WEATHER CONDITIONS ARE QUITE SIMILAR
TO 24 HOURS AGO WITH TEMPERATURES ALONG THE ISLAND CHAIN IN THE
LOWER TO MID 80S AND DEWPOINTS IN THE UPPER 70S. MODERATE EAST TO
SOUTHEAST BREEZES PREVAIL ON THE REEF TRACT REINFORCED BY HIGH
PRESSURE NOSED OVER MAINLAND FLORIDA. A FEW MORE SHALLOW LINES OF
LOW CLOUDS APPEAR UPSTREAM BUT LOOKS NOTABLY DRIER THAN THIS TIME
YESTERDAY.
THE BIG WEATHER STORY TODAY FOR THE KEYS IS THE SAHARAN AIR LAYER
(SAL) CURRENTLY ADVECTING INTO OUR AREA. WITH THE MID TO UPPER
LEVEL TROUGH FROM LAST WEEK LOSING ITS INFLUENCE TO RIDGING
BUILDING BACK INTO THE AREA, THE SAL RIDING ALONG THE PERIPHERY
OF THE PREVIOUSLY MENTIONED RIDGE FINALLY MAKES ITS PASS ACROSS
THE KEYS THIS WEEKEND. WHILE OUR 00Z BALLOON SOUNDING FROM
YESTERDAY EVENING WAS TOO EARLY TO CAPTURE THE DRY AIR FILTERING
IN ALOFT, CIMSS MIMIC TPW SHOWS DRIER VALUES PRESENT OVER THE
FLORIDA KEYS THIS MORNING. THIS IS ALSO SUPPORTED BY A LACK OF
PRECIPITATION IN OUR CWA. WHILE THIS FORECAST IS ABOUT AS DRY AS
IT CAN GET FOR THIS TIME OF YEAR, WET SEASON LIKES TO BE SOMEWHAT
UNRULY WHEN IT COMES TO CONVECTIVE DEVELOPMENT SO HAVE OPTED TO
GO WITH DIME POPS WITH A SLIGHT CHANCE OF THUNDER OVER THE NEXT 24
HOURS OR SO TO COVER POSSIBLE ISOLATED INCIDENTS OF SHOWERS
POPPING UP BRIEFLY.
RAIN CHANCES WILL RETURN TO NEAR NORMAL SUNDAY AS THE SAL PUSHES
WEST PAST THE KEYS. POPS WILL FURTHER INCREASE AT THE START OF THE
WEEK AS YET ANOTHER UPPER LEVEL TROUGH CYCLES ITS WAY TOWARDS THE
KEYS. GUIDANCE LOOKS TO PLACE THIS FEATURE ON OUR DOORSTEP
SOMETIME MONDAY ALONG WITH BOTH A SURFACE REFLECTION AND A FRESH
UNDULATION OF TROPICAL MOISTURE. OF COURSE, THERE IS STILL
UNCERTAINTY IN BOTH THE EXACT PLACEMENT OF SYNOPTIC PLAYERS HERE
ALONG WITH MOISTURE AVAILABLE FOR CONVECTION, SO POPS HAVE BEEN
MERELY NUDGED UP FOR MONDAY AND MONDAY NIGHT TO NOTE THE PERIOD
MOST LIKELY TO SEE RAIN ACCORDING TO RECENT MODEL RUNS. THIS
TIMING WILL CONTINUE TO BE REFINED AS WE APPROACH THE START OF THE
WEEK. AS FOR THE REST OF THE FORECAST PERIOD, SEASONAL
TEMPERATURES AND POPS ARE CURRENTLY ON TAP.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 88 81 89 81 / 10 20 30 40
MARATHON 89 81 90 81 / 10 20 40 40
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...BT
AVIATION/NOWCASTS....BT
DATA ACQUISITION.....BT
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