506
FXUS62 KKEY 310833
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
433 AM EDT MON AUG 31 2026
..NEW DISCUSSION, MARINE, AVIATION
KEY MESSAGES
- CHANCE OF SHOWERS AND THUNDERSTORMS EXPECTED TODAY AND TONIGHT.
THERE IS ALSO THE LOW RISK FOR A CLOUD LINE THIS AFTERNOON.
- MAINLY LIGHT TO GENTLE BROADLY EASTERLY BREEZES WILL CONTINUE
THROUGH THE FIRST HALF OF THE WEEK.
- THE REMNANTS OF DOLLY REMAIN NEAR PUERTO RICO AND THE VIRGIN
ISLANDS AND MAY BRING A PERIOD OF MUCH HIGHER RAIN CHANCES BY
THE MIDDLE OF THE WEEK.
DISCUSSION
ISSUED AT 433 AM EDT MON AUG 31 2026
CIMSS PRODUCTS CONTINUES TO SHOW MEAN LAYER RIDGING DOMINATING
MUCH OF THE ATLANTIC AS WELL AS THE ARK-LA-TEX REGION EASTWARD
THROUGH THE SOUTHEAST U.S. TROUGHING CONTINUES FOR THE WEST COAST
WITH MORE OF A ZONAL FLOW RIDING OVER THE TOP OF THE RIDGE ACROSS
THE GREAT LAKES AND THE NORTHEAST U.S. AT THE SURFACE, THE WESTERN
SIDE OF THE HIGH OVER THE ATLANTIC MAINTAINS CONTROL ACROSS THE
KEYS. MARINE OBSERVATION PLATFORMS SURROUNDING THE ISLAND CHAIN
ARE RECORDING MAINLY EAST BREEZES OF 5 TO 10 KNOTS AS A RESULT.
GOES 19 TOTAL PRECIPITABLE WATER (TPW) PRODUCTS SHOWS ABUNDANT
MOISTURE ACROSS THE AREA WITH ESTIMATED PWATS RANGING FROM 1.85 TO
2.4 INCHES. KBYX RADAR HAS REMAINED SOMEWHAT ACTIVE OVERNIGHT
WITH A FEW SHOWERS INITIALLY ACROSS THE UPPER KEYS AND THE STRAITS
OF FLORIDA TO THE SOUTH OF THE LOWER KEYS. HOWEVER, OVER THE LAST
HOUR OR TWO, ADDITIONAL SHOWERS DEVELOPED IN THE VICINITY OF THE
DRY TORTUGAS ACROSS THE SE GULF WHILE THE EARLIER ACTIVITY ACROSS
THE UPPER KEYS AND STRAITS FIZZLED OUT. TEMPERATURES ALONG THE
ISLAND CHAIN ARE IN THE LOWER TO MID 80S AND DEW POINTS ARE IN THE
UPPER 70S TO NEAR 80 DEGREES.
FORECAST
EVER SO SLIGHTLY DRIER AIR HAS MOVED INTO THE KEYS EARLY THIS
MORNING. THEREFORE, WHILE WE STILL EXPECT SHOWERS AND
THUNDERSTORMS, WE DON'T EXPECT THE ACTIVITY TO BE AS WIDESPREAD
FOR TODAY AND TONIGHT. THEREFORE, POPS WERE LOWERED SLIGHTLY TO
30% FOR THIS FRAME. THE THEME REMAINS THE OVERALL SAME THOUGH WITH
AN ATLANTIC RIDGE CONTINUING TO EXTEND ITS WESTERN PERIPHERY INTO
THE KEYS. GLOBAL AND NUMERICAL MODEL GUIDANCE REMAIN IN AGREEMENT
THROUGH AT LEAST TUESDAY NIGHT FOR A SLIGHTLY DRIER PERIOD FROM
TODAY THROUGH TUESDAY NIGHT. THE POPS ARE AS FOLLOWS 30% TONIGHT,
40% TUESDAY, AND 30% FOR TUESDAY NIGHT. ALSO, WITH A SLIGHTLY
LIGHTER WIND REGIME TODAY, THERE IS THE POTENTIAL THAT A CLOUD
LINE MAY TRY TO DEVELOP DURING THE AFTERNOON, THOUGH, THIS IS LOW
CONFIDENCE AT THIS TIME. IT MAY HAPPEN AGAIN TUESDAY AFTERNOON AS
WELL.
WITH THAT SAID, THE FORECAST FOR MID TO LATE WEEK WHILE STILL
LOOKING INTERESTING ISN'T LOOKING AS FAVORABLE AS IT DID BEFORE.
GLOBAL AND NUMERICAL GUIDANCE VIRTUALLY SHOW THE REMNANTS OF DOLLY
TOTALLY FIZZLING OUT AS IT MOVES INTO CUBA. HOWEVER, THE NORTHERN
FRINGE OF THE MOISTURE ASSOCIATED WITH IT MAY GRAZE THE KEYS
WEDNESDAY/THURSDAY TIME FRAME. THE REMNANTS AND ITS MOISTURE WILL
CONTINUE MOVING WEST NORTHWEST GLIDING ALONG THE NORTHERN FRINGE
OF HISPANIOLA AND EVENTUALLY MOVING RIGHT INTO THE EASTERN SIDE OF
CUBA. IT APPEARS THAT THE NORTHERN FRINGE OF THE MOISTURE
ASSOCIATED WITH DOLLY REACHES THE KEYS SOMETIME WEDNESDAY AND
CONTINUES TO AFFECT THE REGION THROUGH THURSDAY/THURSDAY NIGHT
BEFORE CONTINUING NORTHWESTWARD INTO THE GULF. THEREFORE, LIKELY
POPS ARE IN THE FORECAST FOR THIS TIME FRAME AT 60%. IT TURNS OUT
THE MAIN TAKEAWAY FOR THIS TIME FRAME WILL BE TO POTENTIALLY
EXPECT SLIGHTLY FRISKIER SHOWERS AND THUNDERSTORMS AND AN
INCREASE IN CLOUD COVER.
BEHIND THE REMNANTS OF DOLLY, MOISTURE WILL REMAIN, JUST NOT AS
DEEP AS THE MID TO LATE WEEK TIME FRAME. RAIN CHANCES RETURN BACK
TO CHANCES (40-50%), THOUGH, STILL REMAIN ELEVATED FOR LATE WEEK
AND INTO THE HOLIDAY WEEKEND. AFTER ALL, IT IS SEPTEMBER AT THIS
POINT.
THE KEYS REMAIN ON THE WESTERN PERIPHERY OF THE ATLANTIC RIDGE
THROUGH MUCH OF THE WEEK. THIS WILL CONTINUE TO YIELD TO PEAKING
AND LULLING BREEZES THROUGH THE MIDDLE PART OF THIS WEEK. HOWEVER,
THE WIND DIRECTION WILL ALSO FOLLOW SUIT WITH EAST TO SOUTHEAST
BREEZES DURING THE EARLY MORNING TO EARLY AFTERNOON HOURS FOLLOWED
BY NORTHEAST TO EAST BREEZES IN THE MID TO LATE AFTERNOON INTO
THE EARLY OVERNIGHT HOURS. BREEZES WILL STABILIZE A LITTLE BIT
MORE TOWARDS THE END OF THE WEEK WITH MAINLY EAST TO SOUTHEAST
LIGHT TO GENTLE BREEZES ANTICIPATED. DAYTIME HIGHS WILL CONTINUE
TO BE NEAR 90 DEGREES WITH OVERNIGHT LOWS IN THE LOWER TO MID 80S,
COOLER IN AND NEAR SHOWER AND STORMS. DEW POINTS WILL REMAIN
SOUPY IN THE MID TO UPPER 70S. SEPTEMBER STARTS IN LESS THAN 24
HOURS AND FLORIDA WILL CONTINUE TO LIVE UP TO ITS NAME FOR THIS
TIME OF YEAR WITH DAILY RAIN CHANCES.
TROPICS: THE NATIONAL HURRICANE CENTER (NHC) CONTINUES TO MONITOR
TWO AREAS FOR POTENTIAL TROPICAL CYCLONE DEVELOPMENT. THE FIRST
IS NEAR PUERTO RICO AND THE VIRGIN ISLANDS (REMNANTS OF DOLLY)
WHICH HAS A LOW OR NEAR 0 PERCENT CHANCE OF DEVELOPMENT THROUGH 48
HOURS AND A LOW OR 20 PERCENT CHANCE OF DEVELOPMENT THROUGH THE
NEXT 7 DAYS. THE SECOND AREA BEING WATCHED FOR TROPICAL CYCLONE
DEVELOPMENT IS CURRENTLY IN THE NORTHERN GULF OF AMERICA (INVEST
97L). THIS SYSTEM HAS A HIGH OR 705 CHANCE OF TROPICAL DEVELOPMENT
THROUGH BOTH THE NEXT 48 HOURS AND 7 DAYS. BOTH OF THESE SYSTEMS
CURRENTLY POSE NO THREAT TO THE FLORIDA KEYS, THOUGH, DOLLY'S
REMNANTS MAY VERY WELL BRING AN INCREASE IN RAIN CHANCES TO THE
KEYS.
MARINE
ISSUED AT 433 AM EDT MON AUG 31 2026
THERE ARE CURRENTLY NO WATCHES, WARNINGS, OR ADVISORIES IN EFFECT
ACROSS THE FLORIDA KEYS COASTAL WATERS. FROM SYNOPSIS, THE
WESTERN PERIPHERY OF AN ATLANTIC HIGH REMAINS IN CONTROL OF THE
KEYS FOR THE NEXT SEVERAL DAYS. THEREFORE, EXPECT CONTINUED
PEAKING AND LULLING BREEZES. THE DIRECTION WILL ALSO SHIFT OVER
THE NEXT FEW DAYS WITH EAST TO SOUTHEASTERLY BREEZES OVERNIGHT AND
IN THE MORNING WITH NORTHEAST TO EAST BREEZES LATE AFTERNOON AND
EVENING. IN ADDITION, THE OVERALL FLOW WILL 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
(06Z TAFS)
ISSUED AT 433 AM EDT MON AUG 31 2026
VFR CONDITIONS ARE EXPECTED TO PERSIST AT BOTH EYW AND MTH
TERMINALS THROUGH THE TAF PERIOD. NEAR SURFACE WINDS WILL REMAIN
EAST TO SOUTHEAST INTO THE EARLY TO MID AFTERNOON HOURS BEFORE
SHIFTING TO THE NORTHEAST TO EAST FOR THE LATE AFTERNOON THROUGH
EARLY OVERNIGHT HOURS. CHANCES OF SHOWERS AND THUNDERSTORMS REMAIN
FOR TODAY, THOUGH NOT NEARLY AS WIDESPREAD AS PREVIOUS DAYS. THERE
IS ALSO THE LOW RISK FOR A POTENTIAL CLOUD LINE THIS AFTERNOON.
CLIMATE
ON THIS DAY IN 1872, THE DAILY RECORD RAINFALL OF 1.54" WAS
RECORDED IN KEY WEST. RAINFALL RECORDS FOR KEY WEST DATE BACK TO
1871.
ON THIS DAY IN 1962, THE DAILY RECORD RAINFALL OF 2.24" WAS
RECORDED IN MARATHON. RAINFALL RECORDS FOR MARATHON DATE BACK TO
JUNE 1950.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 90 83 90 83 / 30 30 40 30
MARATHON 90 82 90 82 / 30 30 40 30
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...MJV
AVIATION/NOWCASTS....MJV
DATA ACQUISITION.....MJV
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