854
FXUS62 KKEY 281520
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1120 AM EDT FRI AUG 28 2026
..NEW DISCUSSION, MARINE, AVIATION, PREV DISCUSSION
KEY MESSAGES
- CHANCE OF SHOWERS AND THUNDERSTORMS EXPECTED TODAY AND TONIGHT.
- MAINLY LIGHT TO GENTLE EAST TO SOUTHEAST BREEZES WILL CONTINUE
INTO THE WEEKEND, THOUGH OCCASIONAL PERIODS OF MODERATE BREEZES
WILL OCCUR, ESPECIALLY SOUTH OF THE ISLAND CHAIN.
DISCUSSION
ISSUED AT 1052 AM EDT FRI AUG 28 2026
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO DRIFT
TOWARDS THE WEST TO NORTHWEST ACROSS THE FLORIDA KEYS COASTAL
WATERS, ESPECIALLY IN THE STRAITS OF FLORIDA. COVERAGE HAS BEGUN
TO DWINDLE OVER THE LAST HOUR, AND AN OUTFLOW BOUNDARY IS EVIDENT
ON VIS SATELLITE IMAGERY MOVING NORTHWARD THROUGH THE HAWK
CHANNEL AND NEAR AND PARALLEL TO THE LOWER TO MIDDLE KEYS. THIS
BOUNDARY IS WELL NORTH OF THE EARLIER CONVECTION IT SPAWNED FROM
IN THE STRAITS, WHICH HAS NOW MOSTLY DISSIPATED, AND A FEW OF THE
MARINE OBSERVATIONS IN THE HAWK CHANNEL ARE ONLY REPORTING WIND
GUSTS AROUND 10 TO 15 KNOTS. THE MAIN THING TO WATCH IS WHETHER OR
NOT ADDITIONAL THUNDERSTORMS WILL INITIATE ALONG THE BOUNDARY,
BUT RIGHT NOW VERTICAL CLOUD DEPTH ALONG THE BOUNDARY IS RATHER
SHALLOW. NEARLY 2" PWATS WERE MEASURED ON THE 12Z KKEY RAOB, SO IF
NOTHING ELSE, THE ELEVATED MOISTURE CONTENT WILL SUPPORT SLIGHT
CHANCE TO CHANCE POPS ACROSS THE AREA THIS AFTERNOON WITH
ADDITIONAL DEVELOPMENT DRIVEN PRIMARILY BY MESOSCALE BOUNDARIES.
LATEST HI-RES GUIDANCE DOES SUPPORT ADDITIONAL DEVELOPMENT
OVERNIGHT IN THE SURROUNDING COASTAL WATERS, SO WILL MAINTAIN
CHANCE POPS IN THE FORECAST FOR TONIGHT.
MARINE
ISSUED AT 1052 AM EDT FRI AUG 28 2026
THE INFLUENCE OF PERSISTENT CENTRAL ATLANTIC RIDGING IS EVIDENT
BY CURRENT MARINE OBSERVATIONS WHICH ARE REPORTING EAST TO
SOUTHEAST LIGHT TO GENTLE BREEZES. ISOLATED SHOWERS AND A FEW
THUNDERSTORMS ARE ONGOING ACROSS THE FLORIDA KEYS COASTAL WATERS,
BUT PRIMARILY IN THE STRAITS OF FLORIDA. COVERAGE HAS BEGUN TO
DWINDLE OVER THE LAST HOUR OR SO. MARINERS ENCOUNTERING THIS
ACTIVITY CAN EXPECT REDUCED VISIBILITY FROM HEAVY DOWNPOURS, WIND
GUSTS NEAR 25 KNOTS, AND OCCASIONAL LIGHTNING STRIKES. FROM
SYNOPSIS, THE WESTERN PERIPHERY OF AN ATLANTIC HIGH IS EXPECTED
TO MAINTAIN CONTROL OF THE KEYS FOR THE NEXT SEVERAL DAYS. THIS
WILL CONTINUE TO PROMOTE PEAKING AND LULLING EAST TO SOUTHEAST
BREEZES. BREEZES WILL PEAK IN THE EVENING THROUGH EARLY MORNING
HOURS AND LULL IN THE AFTERNOONS. IN ADDITION, THE SOUTHEASTERLY
FLOW WILL ALSO KEEP DEEP MOISTURE IN PLACE ACROSS THE REGION WITH
DAILY CHANCES OF SHOWERS AND THUNDERSTORMS. LOCALLY HAZARDOUS
WINDS AND SEAS ARE EXPECTED IN THE VICINITY OF THUNDERSTORM
ACTIVITY.
AVIATION
(15Z TAFS)
ISSUED AT 1052 AM EDT FRI AUG 28 2026
ISOLATED SHOWERS AND A THUNDERSTORM OR TWO WILL PERSIST NEAR KMTH
AND KEYW THROUGH AT LEAST 19Z WITH COVERAGE EXPECTED TO DECREASE
THEREAFTER. DUE TO LIMITED COVERAGE, WILL MAINTAIN VICINITY
MENTION IN THE TAF, BUT WILL AMEND IF NEEDED. PREVAILING VFR
CONDITIONS ARE EXPECTED FOR MUCH OF THE AFTERNOON AND THROUGH THE
REMAINING TAF PERIOD. THE FLORIDA KEYS REMAINS UNDER THE
PERSISTENT INFLUENCE OF AN ATLANTIC RIDGE WHICH WILL SUPPORT
EAST-SOUTHEASTERLY SFC WINDS OF 5 TO 8 KTS.
PREV DISCUSSION
ISSUED AT 437 AM EDT FRI AUG 28 2026
CIMSS PRODUCTS CONTINUES TO SHOW THE SPLIT RIDGE PATTERN THAT HAS
DOMINATED FOR MUCH OF THE PAST WEEK REMAINING IN PLACE. THE MAIN
CHANGES HAVE BEEN INTENSITY WITH THE RIDGE JUST SOUTH OF THE FOUR
CORNERS REGION WHICH IS STRONGER THAN IT WAS THIS TIME YESTERDAY.
THE OTHER RIDGE REMAINS OVER THE ATLANTIC JUST SOUTHWEST OF THE
AZORES. IN BETWEEN THE TWO RIDGES, MEAN LAYER TROUGHING REMAINS
ACROSS MUCH OF THE EASTERN UNITED STATES, THOUGH, THIS TROUGH HAS
DUG A BIT FURTHER SOUTH INTO THE GULF EARLY THIS MORNING. AT THE
SURFACE, THE WESTERN PERIPHERY OF THE ATLANTIC RIDGE NUDGES INTO
THE KEYS. MARINE OBSERVATION PLATFORMS SURROUNDING THE ISLAND
CHAIN ARE RECORDING EAST TO SOUTHEAST BREEZES OF 5 TO 10 KNOTS AS
A RESULT. GOES 19 TOTAL PRECIPITABLE WATER (TPW) PRODUCTS SHOWS
ESTIMATED PWATS OF 1.8 TO 2 INCHES IN PLACE THROUGHOUT THE KEYS.
ONE WOULD THINK THIS WOULD BE ENOUGH TO MUSTER UP A BUNCH OF
SHOWERS AND THUNDERSTORMS. KBYX RADAR HAS ONLY DETECTED A COUPLE
BABY SHOWERS AND A TINY THUNDERSTORM EARLIER IN THE FLORIDA BAY
WHICH LASTED ALL BUT 5 MINUTES, THOUGH BETWEEN 3-4AM, WE NOTICED
ACTIVITY STARTING TO INCREASE, ESPECIALLY OVER THE MARINE AREA.
TEMPERATURES ALONG THE ISLAND CHAIN ARE IN THE MID 80S AND DEW
POINTS ARE IN THE MID TO UPPER 70S.
FORECAST
THE FORECAST FOR TODAY IS TRICKY TO SAY THE LEAST. MULTIPLE CAMS-
CONVECTIVE ALLOWING MESOSCALE SYSTEM MODELS SHOW QUITE THE RAMP UP
IN ACTIVITY SHORTLY AFTER DAYBREAK, ESPECIALLY IN THE VICINITY OF
THE UPPER KEYS. ANY ACTIVITY THAT FORMS, IF THEY DO, ARE
ANTICIPATED TO MOVE SOUTHWEST TO WEST THROUGH THE KEYS WITH THE
THREAT ENDING BY THE EARLY AFTERNOON. NEARLY ALL THE GUIDANCE
SHOWS A SHOWER/STORM FREE LATE AFTERNOON THROUGH EVENING AND INTO
THE OVERNIGHT HOURS. HOWEVER, WITH THAT SAID, A SHOWER OR STORM
OR TWO STILL CANNOT BE COMPLETELY RULED OUT. DUE TO THE NATURE OF
THE PAST FEW DAYS, RAIN CHANCES HAVE BEEN NUDGED DOWN ACROSS THE
BOARD FOR TODAY AND TONIGHT WITH 30% FOR TODAY AND 20% TONIGHT.
GUIDANCE SUGGESTS THIS PATTERN ONCE AGAIN SHOWING MORE MOISTURE
AND EVEN SOME ADDED UPPER LEVEL SUPPORT AS WE HEAD THROUGH THE
WEEKEND. THEREFORE, THE RAIN CHANCES RETURN TO 40% FOR SATURDAY
AND SATURDAY NIGHT WITH 50% FOR SUNDAY. GRANTED WITH THE WAY THIS
PATTERN HAS BEEN PLAYING OUT, ADJUSTMENTS TO THE RAIN CHANCES ARE
PLAUSIBLE. OUTSIDE OF THE MOISTURE, EAST TO SOUTHEAST BREEZES WILL
CONTINUE TO BE ON A PEAKING AND LULLING REGIME. PEAK BREEZES WILL
CONTINUE TO BE DURING THE EVENING AND OVERNIGHT WITH LULLS DURING
THE AFTERNOONS AS THE WESTERN PERIPHERY OF THE ATLANTIC HIGH
MAINTAINS CONTROL. DAYTIME HIGHS NEAR 90 DEGREES WITH OVERNIGHT
LOWS IN THE LOWER TO MID 80S.
GLOBAL AND NUMERICAL MODEL GUIDANCE SUGGESTS THIS PATTERN
REMAINING INTO THE MIDDLE OF NEXT WEEK WITH ELEVATED RAIN CHANCES
CONTINUING AND BREEZES PEAKING AND LULLING THROUGH THE PERIOD.
HOWEVER, RAIN CHANCES WILL BE SUBJECT TO CHANGE AS WE HAVE SEEN IN
RECENT DAYS. A COMPLICATED PATTERN TO SAY THE LEAST ESPECIALLY
SINCE WE HAVE ALL THIS MOISTURE IN PLACE BUT IT HAS BEEN A
STRUGGLE AT TIMES TO KEEP SHOWERS AND THUNDERSTORMS ONGOING. ALSO,
SEPTEMBER IS 4 DAYS AWAY AND ALSO THE TIME WHEN AVERAGE RAIN
CHANCES PEAK (35%). THEREFORE, DAILY SHOWERS AND THUNDERSTORMS ARE
PERFECTLY NORMAL FOR THIS TIME OF THE YEAR.
TROPICS: THE NATIONAL HURRICANE CENTER (NHC) IS CONTINUING
ADVISORIES ON TROPICAL STORM DOLLY ACROSS THE CENTRAL TROPICAL
ATLANTIC AND THIS SYSTEM DOES NOT POSE A THREAT TO THE FLORIDA
KEYS.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 90 83 91 83 / 20 10 30 40
MARATHON 90 83 90 83 / 30 20 40 40
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...DM/MJV
AVIATION/NOWCASTS....DM
DATA ACQUISITION.....DM
VISIT US ON THE WEB AT WEATHER.GOV/KEY
FOLLOW US ON FACEBOOK AND X AT:
WWW.FACEBOOK.COM/NWSKEYWEST
WWW.X.COM/NWSKEYWEST
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page