836
FXUS62 KKEY 301756
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
156 PM EDT MON JUN 30 2025
..NEW DISCUSSION, MARINE, AVIATION, PREV DISCUSSION
AVIATION
(18Z TAFS)
ISSUED AT 149 PM EDT MON JUN 30 2025
VFR CONDITIONS WILL PREVAIL AT BOTH ISLAND TERMINALS THROUGH 18Z
TUESDAY AFTERNOON, WITH EAST TO SOUTHEAST WINDS GENERALLY 8 TO 10
KNOTS. ADDITIONAL SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS
MAY FORM THIS EVENING AND OVERNIGHT, ALTHOUGH CONFIDENCE IN
TIMING AND EVOLUTION BARS FROM INCLUSION IN THE TAFS FOR NOW.
DISCUSSION
ISSUED AT 1130 AM EDT MON JUN 30 2025
SATELLITE-DERIVED PRODUCTS CONTINUE TO DETECT THE BEGINNING OF THE
END FOR THE LATEST SAHARAN AIR LAYER (SAL) EVENT. THE VAST
MAJORITY OF THE DETECTED AEROSOLS HAVE ADVECTED WEST OF THE ISLAND
CHAIN, WITH THE 12Z MORNING SOUNDING AT KEY ALSO SUPPORTIVE OF
THIS EVOLUTION. CIMSS MID- AND UPPER-LEVEL VORTICITY PRODUCTS
HIGHLIGHT CYCLONIC FLOW ASSOCIATED WITH A WELL-DEFINED TROPICAL
UPPER TROPOSPHERIC TROUGH (TUTT) CELL NOW CENTERED NORTH OF THE
BAHAMAS CONTINUE TO GRADUALLY SLIDE WESTWARD TOWARDS THE FLORIDA
SPACE COAST. MEANWHILE, A SECOND AREA OF CYCLONIC FLOW ASSOCIATED
WITH A WEAK TROUGHING FEATURE IS LOCATED NEAR THE BIG BEND REGION
OF FLORIDA. THE FLORIDA KEYS ARE SANDWICHED BETWEEN THESE TWO
FEATURES. EARLY MORNING SHOWERS AND THUNDERSTORMS ALONG A WEAK
BOUNDARY SLID THROUGH THE COASTAL WATERS SOUTH OF THE ISLAND
CHAIN AROUND SUNRISE, REACHED PORTIONS OF THE MIDDLE AND UPPER
KEYS, THEN EVENTUALLY DISSIPATED BEFORE BEING ABLE TO AFFECT MOST
OF THE LOWER KEYS. KBYX RADAR IS CURRENTLY DETECTING LITTLE IN
THE WAY OF SHOWERS DELIVERING MEASURABLE RAINFALL NOW AT THIS LATE
MORNING HOUR.
FOR THE REST OF TODAY, WHILE THERE IS LIKELY SOME SUBSIDENCE
ACROSS THE KEYS CWA (OWED TO BEING ON THE PERIPHERY OF THESE TWO
CYCLONIC FEATURES), SOMEWHAT SUPPRESSED UPPER-LEVEL HEIGHTS, ALONG
WITH A LARGELY UNINHIBITED ENVIRONMENT SHOULD SUPPORT ADDITIONAL
SCATTERED SHOWER AND ISOLATED THUNDERSTORM DEVELOPMENT, INCLUDING
ANY ACTIVITY DEVELOPING OVER SOUTH FLORIDA POSSIBLY NUDGING
SOUTHWESTWARD. MID-LEVEL CHANCE RAIN AND SLIGHT THUNDER CHANCES
STILL SEEMS APPROPRIATE. OUTSIDE OF THE EARLIER INCREASES TO POPS
FOR THE FIRST PERIOD DUE TO EARLY MORNING RADAR TRENDS, NO CHANGES
PROPOSED TO THE INHERITED CURRENT ONCE-PER-DAY OVERNIGHT FULL
FORECAST PACKAGE.
MARINE
ISSUED AT 1130 AM EDT MON JUN 30 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. RAIN CHANCES BRIEFLY TAPER BACK MID-WEEK
BEFORE INCREASING AGAIN LATE THIS WEEK DUE TO A NEW WEATHER
DISTURBANCE SLIDING INTO THE SOUTHEAST US.
FORECAST
ISSUED AT 351 AM EDT MON JUN 30 2025
THE TWO FEATURES MENTIONED ABOVE WILL BE QUITE THE HEADACHE FOR
OUR FORECAST THROUGH THE END OF THE WEEK. DESPITE A HEALTHY AND
LARGE TUTT, THERE IS NOT REALLY A SURFACE REFLECTION TO SPEAK OF.
THIS IN COMBINATION WITH SOME RESIDUAL LOW LEVEL DRY AIR IS LIKELY
CONTRIBUTING TO A LACK OF RAINFALL. IN ADDITION, WE WILL BE GOING
SOUTHERLY JUST OFF THE SURFACE THROUGH THE DAY, WHICH TENDS TO
HAVE A DRYING EFFECT. THAT BEING SAID, IF BOUNDARIES WERE TO
COLLIDE WITH ENOUGH FORCE, THE UPPER LEVEL SUPPORT WOULD AID IN AT
LEAST SUSTAINING BRIEF OUTBURSTS OF CONVECTION. AS A RESULT,
DROPPED RAIN CHANCES AS COVERAGE LOOKS TO BE LIMITED AND NOT ALL
ISLAND COMMUNITIES WILL BE AFFECTED TODAY. TONIGHT AS THE LOW
LEVEL STEERING FLOW REMAINS SOUTHERLY, WE COULD SEE RESIDUAL
SHOWERS AND THUNDERSTORMS COME OFF CUBA AND MOVE NORTHWARD OVER
THE ISLAND CHAIN.
MEANWHILE, THE TUTT WILL SLOWLY MOVE NORTHWEST, THEN NORTH ALONG
THE EAST COAST OF FLORIDA TUESDAY THROUGH WEDNESDAY. AS IT PULLS
FURTHER AWAY FROM THE KEYS, IT WILL PULL THE MOISTURE WITH IT.
THIS WILL LEAD TO A GRADUAL DECLINE IN RAIN CHANCES THROUGH MID-
WEEK. HOWEVER, THIS IS WHERE THE HEADACHE CONTINUES. IF YOU RECALL
THE AFOREMENTIONED WEAK TROUGH, THIS FEATURE WILL GRADUALLY
STRENGTHEN AND PUSH SOUTHWARD ALONG THE FLORIDA PENINSULA AS A
SMALL UPPER LEVEL LOW. AS IT DOES, MOISTURE WILL ONCE AGAIN SURGE
IN ACROSS THE AREA. AT THE SAME TIME, RIDGING ACROSS THE
ATLANTIC, WILL FORCE THIS LOW TO RETROGRADE AND BRIEFLY SLIDE
SOUTHWEST INTO THE GULF LATE FRIDAY INTO SATURDAY. THEN IT WILL
SLOWLY LIFT BACK NORTHWARD OVER THE WEEKEND. THIS WILL KEEP THE
FEATURE CLOSE ENOUGH THAT ACTIVE WEATHER LOOKS MORE LIKELY THIS
WEEKEND. HAVE BEGUN THE UPWARD TREND IN POPS FOR THE UPCOMING
HOLIDAY WEEKEND. IT REMAINS TOO EARLY TO TELL WHAT MAY COME ABOUT
THIS WEATHER DISTURBANCE IF AT ALL. REGARDLESS OF FUTURE
DEVELOPMENT, THIS WILL REMAIN RELATIVELY WELL TO OUR NORTH. FOR
NOW, IMPACTS TO THE FLORIDA KEYS WILL BE LIMITED TO HIGHER RAIN
CHANCES.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 88 81 89 81 / 40 30 20 20
MARATHON 90 82 91 82 / 40 30 20 20
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...BT
AVIATION/NOWCASTS....BT
DATA ACQUISITION.....BT
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