679
FXUS62 KKEY 011821
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
221 PM EDT TUE JUL 1 2025
..NEW DISCUSSION, MARINE, AVIATION, PREV DISCUSSION
AVIATION
(18Z TAFS)
ISSUED AT 214 PM EDT TUE JUL 1 2025
VFR CONDITIONS WILL PREVAIL AT BOTH ISLAND TERMINALS THROUGH 18Z
WEDNESDAY AFTERNOON. AFTER A LULL IN SCATTERED SHOWER AND
ISOLATED THUNDERSTORM ACTIVITY CONTINUING THROUGH 00Z, ADDITIONAL
CONVECTIVE DEVELOPMENT IS POSSIBLE THEREAFTER THROUGH AROUND 06Z.
CONFIDENCE IN TIMING AND EVOLUTION IS TOO LOW TO INCLUDE MENTION
IN THE TAFS AT THIS TIME, ALTHOUGH THIS WILL CONTINUE TO BE
REEVALUATED. ANOTHER WAVE OF SAHARAN DUST WILL LIKELY LIMIT
ADDITIONAL CONVECTIVE ACTIVITY AFTER 06Z THROUGH THE REST OF THE
TAF PERIOD.
MARINE
ISSUED AT 1142 AM EDT TUE JUL 1 2025
NO WATCHES, WARNINGS, OR ADVISORIES ARE IN EFFECT FOR FLORIDA KEYS
COASTAL WATERS ZONES. 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 NORTH OF THE
BAHAMAS WILL CONTINUE TO MOVE SLOWLY NORTHWESTWARD TOWARDS THE
FLORIDA EAST COAST EARLY THIS WEEK, SUPPORTING SLIGHTLY ENHANCED
RAIN AND THUNDER CHANCES. RAIN CHANCES WILL BRIEFLY TAPER BACK
MID-WEEK BEFORE INCREASING AGAIN LATE THIS WEEK DUE TO A NEW
WEATHER DISTURBANCE SLIDING INTO THE SOUTHEAST UNITED STATES.
PREV DISCUSSION
ISSUED AT 1142 AM EDT TUE JUL 1 2025
CIMSS SATELLITE-DERIVED VORTICITY ANALYSIS PLACES AN EXPANSIVE
CYCLONIC UPPER-LEVEL GYRE EXTENDING FROM THE EASTERN GULF
EASTWARD TO WELL EAST OF THE BAHAMAS. THIS FORCING FOR UPPER-
LEVEL VENTILATION, COMBINED WITH A MOISTURE SURGE IN THE WAKE OF A
WAVE OF SAHARAN DUST, AS WELL AS COPIOUS OUTFLOW BOUNDARIES FROM
THE MAINLAND AND CUBA SUPPORTED SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS FOR LAST NIGHT'S OVERNIGHT PERIOD THROUGH AROUND
SUNRISE. CONVECTIVE AVAILABLE POTENTIAL ENERGY (CAPE) HAS SINCE
BEEN EXHAUSTED, WITH RECENT GOES VISIBLE SATELLITE TRENDS
HIGHLIGHTING MOSTLY SUNNY SKIES ACROSS THE KEYS AND THE ADJACENT
NEARSHORE AND OFFSHORE MARINE ZONES. TEMPERATURES ARE FINALLY
RISING INTO THE UPPER 80S AT THIS LATE MORNING HOUR.
FOR THIS AFTERNOON, COUPLED WITH THE NEED FOR RECHARGING OF CAPE,
SOUTHEAST TO SOUTH LOW- LEVEL STEERING FLOW WILL SUPPORT SOME
TEMPORARY MOISTURE PROFILE DRYING, WITH LOW RAIN AND THUNDER
CHANCES EXPECTED. THEREAFTER, WITH THE UPPER-LEVEL CYCLONIC FLOW
STILL IN THE VICINITY OF THE FLORIDA KEYS, WE WILL NEED TO WATCH
FOR ADDITIONAL CONVECTION OVER THE MAINLAND TO INTERACT WITH ANY
DEVELOPING STORMS OVER CUBA TO SEE IF/WHEN ADDITIONAL REDEVELOPMENT
OCCURS THIS EVENING AND THROUGH AT LEAST THE EARLY OVERNIGHT
HOURS. OVERALL, THIS FORECAST REASONING IS CONSISTENT WITH THE
INHERITED ONCE-PER-DAY FULL FORECAST PACKAGE CRAFTED OVERNIGHT. NO
CHANGES PROPOSED.
FORECAST
ISSUED AT 505 AM EDT TUE JUL 1 2025
IT HAS CERTAINLY BEEN A TUMULTUOUS OVERNIGHT ACROSS MOST OF THE
FLORIDA KEYS. A SLEW OF BOUNDARIES FROM ALL DIRECTION CONVERGED
AND COLLIDED ACROSS THE FLORIDA KEYS AND SURROUNDING COASTAL
WATERS. BUT EVEN WITH ALL THE ACTIVITY THAT HAS OCCURRED AND
REMAINS ONGOING, THE MIDDLE KEYS HAVE MISSED OUT ON MOST OF THE
PRECIPITATION. THE UPPER KEYS PICKED UP 1 TO 3 INCHES, WITH THE
LOWER KEYS PICKING UP A HALF TO ONE INCH THUS FAR. THE MIDDLE KEYS
HAVE SEEN AT MOST AROUND A TENTH OF AN INCH. THERE REMAINS A
HEALTHY CLUSTER STILL ACROSS THE STRAITS OF FLORIDA BUT WE ARE
OBSERVING A NOTICEABLE DOWNWARD TREND ON RADAR. WHERE IT HAS
RAINED, TEMPERATURES TOOK A TUMBLE DOWN INTO THE MID 70S, A NICE
REPRIEVE FROM THE MILDER LOWER 80S.
GOING FORWARD TODAY, MOST OF OUR RAIN CHANCES WILL BE LIMITED TO
THIS MORNING. AS WE GO INTO THE AFTERNOON, A TUTT CELL LOCATED OFF
THE EAST COAST OF FLORIDA WILL CONTINUE A NORTHWARD TREK. AS THIS
FEATURE PULLS FURTHER AWAY FROM THE KEYS, THE LOW LEVEL STEERING
FLOW WILL GO MORE SOUTHERLY. THIS COUPLED WITH RELATIVELY DRIER
AIR PIVOTING AROUND THE PERIPHERY OF A SPRAWLING ATLANTIC RIDGE,
WILL PROVIDE LOWER RAIN CHANCES THIS AFTERNOON INTO THE EVENING.
MEANWHILE, LURKING ALONG THE ENTIRE EASTERN SEABOARD IS A QUASI-
STALLED TROUGH AND ASSOCIATED SURFACE BOUNDARY THAT STRETCHES
INTO THE NORTHEASTERN GULF. THESE FEATURES WILL VERY SLOWLY SLIDE
SOUTHEAST AND ACROSS THE FLORIDA PENINSULA THROUGH SATURDAY. GIVEN
THE SLOW PROGRESSION, IT WILL TAKE TIME FOR THE FLORIDA KEYS TO
SEE MUCH IN THE WAY OF INCREASED RAIN CHANCES. AS OF RIGHT NOW,
BETTER RAIN CHANCES RETURN FRIDAY, PEAKING FRIDAY NIGHT INTO
SATURDAY.
THEREAFTER, A POTENT UPPER LEVEL SHORTWAVE DIVING SOUTHWARD WILL
MOVE INTO THE BASE OF THIS TROUGH AND STRENGTHEN INTO POTENTIALLY
A CLOSED-OFF LOW. THIS WILL INTERACT WITH THE LINGERING SURFACE
BOUNDARY. THAT BEING SAID, THERE REMAINS A LOT OF UNCERTAINTY AS
TO WHAT THIS INTERACTION WILL ULTIMATELY PRODUCE. GFS HAS A
SURFACE LOW DEVELOP OFF THE GEORGIA/CAROLINA COAST, WHILE THE
ECMWF HAS AN INVERTED TROUGH IN THE SAME REGION. REGARDLESS, THIS
POSES NO IMMEDIATE THREAT TO THE KEYS AT THIS TIME.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 91 82 90 81 / 60 30 20 10
MARATHON 88 82 88 82 / 50 30 20 10
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...BT
AVIATION/NOWCASTS....BT
DATA ACQUISITION.....BT
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