336
FXUS62 KKEY 030851
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
451 AM EDT WED SEP 3 2025
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 450 AM EDT WED SEP 3 2025
CONVECTION HAS ALREADY STARTED TO DEVELOP AROUND THE KEYS AND ITS
COASTAL WATERS THIS MORNING WITH WET WEATHER ON TAP FOR THE NEXT
FEW DAYS. FOR THE LAST FEW HOURS, SCATTERED SHOWERS WITH SOME
EMBEDDED THUNDERSTORMS WERE PERCOLATING IN THE WESTERN STRAITS OF
FLORIDA SOUTH OF THE DRY TORTUGAS AND LOWER KEYS. WHILE INDIVIDUAL
CELLS WERE NOT VERY IMPRESSIVE, A FEW WERE ABLE TO BUILD UP TO
THROW SOME LIGHTNING BOLTS. MORE RECENTLY, KAMX RADAR DETECTED A
NEW CLUSTER OF CONVECTION PULSING IN THE NEARSHORE WATERS OF THE
UPPER AND MIDDLE KEYS SHOWING THAT THE ATMOSPHERIC PROFILE IS
STILL UNSTABLE AND JUICED EVEN IN THE WEE HOURS OF THE MORNING.
ALL OVERNIGHT ACTIVITY HAS BEEN MOVING EAST AT 10 TO 15 KNOTS OR
SO FOLLOWING THE SAME DIRECTION AS THE GENTLE TO MODERATE WESTERLY
FLOW OBSERVED ACROSS THE REEF. MEANWHILE ON LAND, TEMPERATURES
HAVE FALLEN TO THE EXPECTED LOWS IN THE LOWER 80S AND HOLD STRONG
TO MOIST DEWPOINTS IN THE UPPER 70S.
THIS WET WEATHER PATTERN HAS BEEN IN PLACE ACROSS THE KEYS FOR
SEVERAL DAYS NOW AND THAT DOES NOT LOOK TO CHANGE ANYTIME SOON. A
STATIONARY FRONT FINDS ITSELF PARKED OVER SOUTH FLORIDA AND THE
FLORIDA KEYS THIS MORNING WITH A BROAD ASSOCIATED SURFACE LOW
ANALYZED SOMEWHERE NORTH OF THE BAHAMAS. MID TO UPPER LEVEL TROUGHING
ACROSS EASTERN CONUS ALONG WITH THIS SURFACE LOW WILL CONTINUE TO
PROMOTE WESTERLY BREEZES ACROSS MUCH OF OUR VERTICAL WIND PROFILE
SIMILAR TO WHAT WAS RECORDED IN YESTERDAY EVENING'S 00Z KKEY
BALLOON SOUNDING. LOOKING AT THE GULF IN CIMSS MIMIC TPW, HIGH PW
VALUES INDICATING ROBUST MOISTURE ARE FOUND NOT ONLY OVER OUR
AREA, BUT ALSO UPSTREAM IN THE GULF WATERS. THIS WILL HELP KEEP PW
VALUES CLOSE TO IF NOT BREACHING THE 90TH PERCENTILE OVER THE
NEXT FEW DAYS OR SO. WARM TEMPERATURES PROMOTING SEASONAL
INSTABILITY WITH A HIGH RESERVE OF MOISTURE ADVECTING OVER A
SYNOPTIC BOUNDARY IS A SLAM DUNK FOR HIGH RAIN CHANCES ALONG WITH
A MARGINAL RISK (LEVEL 1 OF 4) FOR EXCESSIVE RAINFALL (VIA THE
WEATHER PREDICTION CENTER) THROUGHOUT THE SHORT TERM.
UNFORTUNATELY, THIS PATTERN WILL LINGER AROUND INTO THE END OF THE
WEEK RESULTING IN MULTIPLE DAYS IN AN ENVIRONMENT CAPABLE OF
PRODUCING POTENTIALLY HEAVY, FLOODING RAINS AT TIMES. THE WIND
FORECAST IS A LITTLE MORE MURKY AS THE FUTURE LOCATION OF THE
BROAD SURFACE LOW IS SOMEWHAT UNCERTAIN. RECENT GUIDANCE HAS IT
OPENING UP INTO A BROAD TROUGH AS IT SHIFTS NORTHEAST THROUGHOUT
TODAY, THUS RESULTING IN A SOMEWHAT LIGHTER FLOW THAN PREVIOUS
RUNS. THAT BEING SAID, A MODERATE TO FRESH WESTERLY SURGE WILL
STILL BE IN THE CARDS ON THE DAILY DEPENDING ON THE ALLOWANCE OF
DAYTIME HEATING ON MAINLAND AND BEHAVIOR OF THE LOW.
WE LOOK TO FINALLY BREAK FREE OF THIS PATTERN SATURDAY AS THE MID
TO UPPER LEVEL TROUGHING AND THE SURFACE LOW EXIT TO THE
NORTHEAST. THIS WILL ALLOW WEAK RIDGING TO SLIDE BACK INTO THE
AREA WITH WINDS GRADUALLY FLIPPING BACK AROUND TO A CLOSER TO
NORMAL SOUTHEASTERLY WIND DIRECTION. WHILE THE BIG PLAYERS FOR
HEAVY RAINFALL WILL BE OUT OF THE PICTURE, ANOTHER UNDULATION OF
MOISTURE LOOKS TO SETTLE IN FROM THE EAST KEEPING RAIN CHANCES
JUST ABOVE NORMAL INTO NEXT WEEK.
MARINE
ISSUED AT 450 AM EDT WED SEP 3 2025
NO WATCHES, WARNINGS, OR ADVISORIES ARE CURRENTLY IN EFFECT FOR
THE COASTAL WATERS OF THE FLORIDA KEYS. FROM SYNOPSIS, A BROAD
SURFACE LOW ALONG A STATIONARY FRONT STRETCHING FROM THE GULF
EASTWARD TO THE FLORIDA PENINSULA WILL MAINTAIN WEST TO NORTHWEST
WINDS ACROSS THE KEYS MARINE ZONES TONIGHT. THE FRONT WILL REMAIN
ROOTED IN PLACE THROUGH THE NEXT FEW DAYS, WHILE THE LOW MEANDERS
NORTHEAST INTO THE WESTERN NORTH ATLANTIC PROMOTING SOUTHWEST TO
WEST BREEZES THROUGHOUT THE WEEK. ABUNDANT MOISTURE WILL PROMOTE
ABOVE NORMAL RAIN AND THUNDER CHANCES THROUGH THE END OF THE WORK
WEEK.
AVIATION
(06Z TAFS)
ISSUED AT 450 AM EDT WED SEP 3 2025
TAFS CONTINUE TO REFLECT A PROLONGED PERIOD OF VCSH DUE TO SHOWER
ACTIVITY GRADUALLY INCREASING THIS MORNING, AND REMAINING IN PLACE
VIRTUALLY ALL DAY TO SOME DEGREE. RECENT TRENDS SUGGEST THAT THE
NEXT OPPORTUNITY FOR REDUCED FLIGHT CATEGORIES MAY BE LATER THIS
AFTERNOON. WILL HOLD OFF ON TEMPO GROUPS FOR THIS PACKAGE DUE TO THE
UNCERTAINTY RELATED TO TIMING AND THE DEGREE OF IMPACT. FUTURE TAF
AMENDMENTS WILL ULTIMATELY BE NEEDED. OUTSIDE OF ANY ACTIVITY,
SURFACE WINDS WILL GENERALLY BE OUT OF THE WEST AT NEAR 10 KNOTS.
CLIMATE
ON THIS DAY IN KEYS WEATHER HISTORY IN 2007, THE DAILY RECORD HIGH
TEMPERATURE OF 95F WAS RECORDED IN KEY WEST. THIS IS ALSO TIED FOR
THE WARMEST TEMPERATURE EVER RECORDED IN SEPTEMBER. TEMPERATURE
RECORDS FOR KEY WEST DATE BACK TO 1872.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 91 79 91 80 / 80 80 80 70
MARATHON 90 79 89 80 / 80 80 80 80
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...JAM
AVIATION/NOWCASTS....DP/MC
DATA ACQUISITION.....JAM
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