970
FXUS62 KKEY 261550
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1150 AM EDT SUN JUL 26 2026
..NEW DISCUSSION, MARINE, AVIATION, PREV DISCUSSION
KEY MESSAGES
- A GENERALLY ACTIVE PATTERN WILL REMAIN IN PLACE WITH ABOVE
NORMAL TO WELL ABOVE NORMAL RAIN CHANCES THROUGH MID WEEK,
PEAKING TONIGHT AND MONDAY.
- HEAT INDICES MAY APPROACH 105 TO 110 DEGREES EACH AFTERNOON FOR
SOME FLORIDA KEYS ISLAND COMMUNITIES, ESPECIALLY IN THE UPPER
KEYS.
DISCUSSION
ISSUED AT 1112 AM EDT SUN JUL 26 2026
OUR KBYX RADAR HAS BEEN BUSY DETECTING POCKETS OF SHOWERS AND
THUNDERSTORMS AS THEY HAVE BEEN WAXING AND WANING OVER THE PAST
FEW HOURS ACROSS OUR FORECAST AREA. AROUND 10 AM, A LINE OF
THUNDERSTORMS FROM LOW LEVEL CONVERGENCE OVER THE GULFSIDE WATERS
BRUSHED ACROSS THE LOWER KEYS, BRINGING BOUTS OF LIGHTNING AND
RAINFALL WITH IT. THE ASOS AT KEY WEST INTERNATIONAL AIRPORT
REPORTED 0.13" OF NEW RAINFALL FROM THESE SHOWERS, AND THIS LINES
UP PRETTY WELL WITH THE RADAR- DERIVED ESTIMATE OF 0.05" 0.15"
ACROSS KEY WEST AND STOCK ISLAND. MRMS HIGHLIGHTS A POCKET OF
HIGHER AMOUNTS, 0.30" TO 0.50", OFFSHORE TO THE NORTH OF KEY WEST,
BIG PINE KEY, AND TO THE SOUTH OF MARATHON. SOME ISLAND
COMMUNITIES MAY HAVE SEEN IN THE LOWER AND MIDDLE KEYS MAY HAVE
SEEN RAINFALL AMOUNTS JUST UNDER THE HALF INCH MARK, BUT WE DO NOT
HAVE ANY REPORTS OR OBSERVATIONS TO CONFIRM THAT. TYPICALLY, WE
ASSOCIATE GUSTY CONDITIONS WITH THUNDERSTORMS, BUT WIND
OBSERVATIONS SHOWED SUSTAINED WINDS NEAR 10 MPH WITH THIS LINE.
THIS WAS LIKELY DUE TO A COMBINATION OF SLOW FORWARD SPEED (AROUND
5 MPH) AND TOWERS THAT WERE NOT PARTICULARLY TALL (CLOUD TOPS
AROUND 15,0000 TO 25,0000 FT).
UPSTREAM, TROUGHING LOOKS LIKE IT IS DIGGING INTO THE SOUTH
FLORIDA AREA. THERE IS A GENERAL NORTHWEST TO SOUTHEAST MOTION TO
THE CLOUD FIELD UPSTREAM FROM THE ISLAND CHAIN, BUT A MORE
SOUTHWEST TO NORTHEAST FLOW JUST TO THE EAST OF US. THE BASE OF
THIS TROUGHING IS LIKELY ACROSS OUR AREA, SO WE EXPECT SURFACE
WINDS TO TAKE ON A NORTHWESTERLY DIRECTION HERE ANY MINUTE. RADAR
TRENDS OFFSHORE OF SWFL SHOW THAT POCKETS OF SHOWERS AND
THUNDERSTORMS ARE STILL FIRING, SO EVEN THOUGH WE ARE ENTERING A
LULL HERE, WE CONTINUE TO EXPECT AN UPTICK IN ACTIVITY AGAIN
LATER. HI RES GUIDANCE IS STRUGGLING A LITTLE BIT WITH REGARDS TO
TIMING, BUT HAS DONE WELL SHOWING THE UP-AND-DOWN PATTERN IN TERMS
OF ACTIVITY ON RADAR. THE 12Z KKEY SOUNDING FROM THIS MORNING
SHOWS A PRIMED ENVIRONMENT WITH APPROXIMATELY 2000 J/KG OF ML CAPE
WITH ONLY AROUND -16 J/KG OF CIN TO OVERCOME. THE PROFILE WAS
SUFFICIENTLY MOIST WITH A CALCULATED PWAT OF 2.02", MUCH HIGHER
THAN THE DAILY MEAN OF 1.77", SO THE 40% CHANCE OF RAIN INHERITED
FROM THE MORNING PACKAGE SEEMS REASONABLE. IT JUST LOOKS LIKE THE
40% WILL BE MORE APPLICABLE TO THE SECOND OF THIS AFTERNOON,
RATHER THAN RIGHT NOW. NO CHANGES ARE PROPOSED WITH THIS MORNING
UPDATE.
DISCUSSION
ISSUED AT 428 AM EDT SUN JUL 26 2026
THE KEYS ARE EXPECTED TO REMAIN ON THE SOUTHERN FLANK OF A BROAD
LONGWAVE TROUGH ACROSS THE EASTERN SEABOARD WITH RIDGING ON EITHER
SIDE OF THIS TROUGH. THIS WILL KEEP INCREASED MOISTURE AND
INSTABILITY ACROSS THE REGION FOR THE NEXT SEVERAL DAYS RESULTING
IN ABOVE NORMAL TO WELL ABOVE NORMAL RAIN CHANCES. RAIN CHANCES
PEAK TONIGHT AND MONDAY WHEN THE MOISTURE AND INSTABILITY ACROSS
THE AREA MAXIMIZES. DECREASING RAIN CHANCES ARE EXPECTED
THEREAFTER AS SLIGHTLY DRIER AIR MOVES IN AND THE LONGWAVE TROUGH
SHIFTS OFF TO THE EAST. OUTSIDE OF THE RAIN AND THUNDER CHANCES,
TYPICAL SUMMERTIME HEAT AND HUMIDITY WILL CONTINUE WITH DAYTIME
HIGHS NEAR 90 DEGREES AND OVERNIGHT LOWS IN THE LOWER 80S. DEW
POINTS IN THE MID TO UPPER 70S COMBINED WITH TEMPERATURES NEAR 90
DEGREES WILL KEEP HEAT INDEX VALUES BETWEEN 105 TO 108 DEGREES
WITH ISOLATED LOCATIONS TO 110 DEGREES. SOUTH TO SOUTHWEST LIGHT
BREEZES THIS MORNING WILL GIVE WAY TO LIGHT TO GENTLE BREEZES THIS
AFTERNOON WHILE ALSO SHIFTING TO THE WEST TO NORTHWEST. AT THE
SURFACE, A FRONTAL BOUNDARY IS EXPECTED TO REMAIN DRAPED ACROSS
FLORIDA FOR MUCH OF THE WEEK. THIS WILL RESULT IN MOSTLY GENTLE TO
MODERATE SOUTHWEST BREEZES.
MARINE
ISSUED AT 1112 AM EDT SUN JUL 26 2026
SURFACE TROUGHING WILL CONTINUE TO DIG ACROSS THE AREA
TODAY, CAUSING LIGHT AND VARIABLE BREEZES TO BACK TO THE NORTHWEST
AND BECOMING GENTLE TO MODESTLY MODERATE. POP UP SHOWERS AND
THUNDERSTORMS WILL CRAWL ACROSS THE LOCAL WATERS. SEAS WILL BE
HIGHER AND WATERS WILL BE ROUGHER IN, AND NEAR, SHOWERS AND
THUNDERSTORMS. BREEZES WILL RETURN FROM THE SOUTHWEST AND WEST AS
THE TROUGH MOVES EAST OF THE FLORIDA PENINSULA EARLY THIS WEEK.
THERE IS GROWING CONFIDENCE OF A RETURN TO AN ACTIVE WEATHER
PATTERN STARTING TONIGHT.
AVIATION
(15Z TAFS)
ISSUED AT 1112 AM EDT SUN JUL 26 2026
UNSETTLED WEATHER ACROSS THE AREA WILL KEEP SCT TO BKN CLOUDS NEAR
FL030, SO OBSERVATIONS MAY SHOW FLIGHT CATEGORIES GOING BACK AND
FORTH BETWEEN VFR AND MVFR THROUGHOUT THE TAF PERIOD AT BOTH
ISLAND TERMINALS. THE BEST CHANCES FOR ACTIVITY AT EITHER AIRFIELD
LOOK LIKE THEY WILL BE FROM NOW UNTIL AROUND 22Z, FOLLOWED BY A
BRIEF LULL, AND THEN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
BEGINNING NEAR 06Z. ANY STRONG THUNDERSTORM MAY PRODUCE AN
INSTANCE OF GUSTY CROSSWINDS AND REDUCED VISIBILITY.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 90 82 90 82 / 40 50 60 40
MARATHON 90 82 90 81 / 40 60 60 40
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...DP
AVIATION/NOWCASTS....DP
DATA ACQUISITION.....DP
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