763
FXUS62 KKEY 190912
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
512 AM EDT TUE AUG 19 2025
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 339 AM EDT TUE AUG 19 2025
THE OVERNIGHT SHIFT STARTED OFF WITH A LITTLE BIT OF ACTIVITY ON
OUR KBYX RADAR AS SOME RESIDUAL SHOWERS AND THUNDERSTORMS FROM
EARLIER IN THE EVENING WERE PUSHING SOUTHWESTWARD ACROSS OUR AREA.
THESE CONTINUED TO DIMINISH INTO THE MIDDLE OF THE NIGHT, BUT WE
ARE CURRENTLY SEEING A SMALL RESURGENCE IN ACTIVITY ACROSS THE
FORECAST AREA. THIS JUST MEANS THAT WE MAY BE SET UP FOR A
BEAUTIFUL SUNRISE THIS MORNING, WITH A FEW ISLAND COMMUNITIES
POSSIBLY SEEING SOME LIGHT SHOWERS WHEN ITS TIME TO HEAD TO WORK
OR SCHOOL. OVERALL BREEZES ARE STILL LIGHT TO GENTLE OUT OF THE
NORTH, BUT ANY COLLAPSING SHOWERS OR THUNDERSTORMS WILL RESULT IN
SOME VARIABILITY.
THE FORECAST OVER THE NEXT FEW DAYS IS A LITTLE MESSY TO SORT OUT,
COURTESY OF MAJOR HURRICANE ERIN. AS OF 5 AM EDT, ERIN WAS
LOCATED ROUGHLY 630 MILES TO THE ENE OF KEY WEST. THE SYSTEM LOOKS
PRETTY LARGE ON SATELLITE, AND WE CAN SEE SOME OF THE HIGHER
CIRRUS CLOUDS ACROSS OUR FORECAST AREA ARE FROM THE "EXHAUST" OF
ERIN. THE CURRENT FORECAST HAS THE SYSTEM TURNING TO THE NORTH
TODAY. AS ERIN PASSES WELL TO OUR EAST, MOISTURE WILL ADVECT FROM
THE NORTH AND SHOWERS AND THUNDERSTORMS COULD BE MORE EFFICIENT AT
PRODUCING HEAVIER SHOWERS. WITH THE FAIRLY SLOW MOVEMENT THE
SYSTEM HAS, MOISTURE WILL BE ABLE TO SORT OF "BUILD UP" IN THE
VERTICAL PROFILE, AND IT IS POSSIBLE THAT THE 30 PERCENT CHANCE OF
RAINFALL WE HAVE ADVERTISED, SPECIFICALLY FOR WEDNESDAY, MAY BE A
LITTLE TOO LOW. REGARDLESS, THE NEXT COUPLE OF DAYS HAVE THE
OPPORTUNITY TO BE A LITTLE WETTER AND A LITTLE CLOUDIER THAN WE
THINK RIGHT NOW, IT JUST DEPENDS ON ERIN'S MOTION.
ONCE ERIN PUSHES FAR ENOUGH NORTHWARD, POSSIBLY FROM THURSDAY
AFTERNOON AND ONWARD, RIDGING WILL BE ABLE TO BUILD BACK IN.
GUIDANCE IS SUGGESTING SUBSTANTIALLY DRY AIR ABOVE 850MB, SO OUR
MOISTURE SOURCE FOR ANY ACTIVITY WILL BE VERY SHALLOW. EVEN THOUGH
SHOWERS WILL STILL BE POSSIBLE, SINCE IT IS AUGUST IN FLORIDA, A
SHALLOW MOISTURE SOURCE MEANS THEY WILL LIKELY BE SHORT LIVED AND
UNABLE TO BUILD INTO THUNDERSTORMS. THE BOTTOM LINE IS THAT
WEATHER CONDITIONS SHOULD FEEL MORE NORMAL ONCE ERIN PUSHES AWAY,
BUT YOU MAY WANT TO KEEP AN UMBRELLA CLOSE UNTIL THEN.
MARINE
ISSUED AT 339 AM EDT TUE AUG 19 2025
THERE ARE NO WATCHES, WARNINGS, OR ADVISORIES IN EFFECT FOR THE
FLORIDA KEYS LOCAL WATERS. FROM SYNOPSIS, MAJOR HURRICANE ERIN
WILL TURN DUE NORTHWARD OVER THE OPEN ATLANTIC OVER THE COURSE OF
TODAY. THE INCREASINGLY EXPANSIVE CIRCULATION OF ERIN WILL RESULT
IN A TRANSITION FROM LIGHT TO GENTLE NORTHERLY BREEZES ACROSS
FLORIDA KEYS COASTAL WATERS OVERNIGHT, TO GENTLE TO MODERATE
NORTHWEST BREEZES TUESDAY AND MODERATE TO FRESH WESTERLY BREEZES
ON WEDNESDAY. A SLIGHT SWELL FROM THE NORTH WILL LEAD TO ELEVATED
SEAS IN NORTHERN PORTIONS OF THE FLORIDA STRAITS. AS HURRICANE
ERIN MIGRATES FARTHER AWAY TOWARD THE NORTH AND NORTHEAST, A WEAK
SUBTROPICAL HIGH PRESSURE RIDGE WILL SETTLE OVER FLORIDA KEYS
COASTAL WATERS, RESULTING IN A LIGHTER WIND PATTERN THURSDAY
THROUGH SATURDAY.
AVIATION
(06Z TAFS)
ISSUED AT 339 AM EDT TUE AUG 19 2025
VFR CONDITIONS WILL PREVAIL AT BOTH ISLAND TERMINALS THROUGH THE TAF
PERIOD. A SIMILAR REGIME TO WHAT OCCURRED YESTERDAY MAY OCCUR TODAY.
CONVECTION IS ANTICIPATED TO FLARE OVER THE MAINLAND AND THEN
POTENTIALLY MOVE SOUTH TO SOUTHWESTWARD OFF THE MAINLAND. AS A
RESULT, WE CANNOT RULE OUT A SHOWER OR THUNDERSTORM TO EITHER
TERMINAL LATE IN THE DAY TO THE EVENING HOURS. DUE TO THE
UNCERTAINTY AND LOW TO AVERAGE CONFIDENCE, VCSH WAS LEFT OUT OF THE
TAF FOR NOW. NEAR SURFACE WINDS WILL REMAIN NORTHERLY THIS MORNING
BETWEEN 3 TO 8 KNOTS BEFORE BECOMING MORE NORTHWESTERLY FOR THE
AFTERNOON AND EVENING.
CLIMATE
ON THIS DAY IN KEYS WEATHER HISTORY, IN 2022, THE DAILY RECORD WARM
LOW TEMPERATURE OF 84F WAS LAST RECORDED IN KEY WEST. TEMPERATURE
RECORDS FOR KEY WEST DATE BACK TO 1872.
ALSO, IN 2024, THE DAILY RECORD WARM LOW TEMPERATURE OF 84F WAS LAST
RECORDED IN MARATHON. TEMPERATURE RECORDS FOR MARATHON DATE BACK TO
1950.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 93 83 93 82 / 30 30 30 30
MARATHON 91 82 91 83 / 30 30 30 30
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...DP
AVIATION/NOWCASTS....MJV
DATA ACQUISITION.....MJV
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