908
FXUS62 KKEY 011840
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
240 PM EDT THU MAY 1 2025
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 154 PM EDT THU MAY 1 2025
MAY DAY BROUGHT ANOTHER DRY, NEARLY BREEZY DAY TO THE FLORIDA
KEYS. TEMPERATURES ACROSS THE ISLAND CHAIN ARE IN THE LOW TO MID
80S WITH DEW POINTS IN THE UPPER 60S. WINDS ARE SLOWLY SHIFTING
EAST TO SOUTHEAST, BUT REMAIN AT OR JUST BELOW BREEZY CRITERIA. ON
THE KBYX RADAR, SHORT LIVED NON-PRECIPITATING CLOUDS ARE SEEN
OVER THE EASTERN FLORIDA STRAITS. GOES-19 OBSERVATIONS IDENTIFY
PATCHES OF DEEPER CUMULUS CLOUDS NEAR THE UPPER KEYS. OVERALL
CONDITIONS ARE VERY QUIESCENT. PERSISTENCE CONTINUES TO BE THE
NAME OF THE GAME, AT LEAST ONE MORE NIGHT OF WINDS JUST BELOW
SMALL CRAFT ADVISORY CRITERIA WITH MINIMAL CLOUD COVER.
PULLING BACK TO THE LARGER ENVIRONMENT, THE BERMUDA HIGH REMAINS
PARKED OFF THE EASTERN SEABOARD. OVER THE GREAT LAKES, A MATURE
LOW PRESSURE SYSTEM IS MAKING ITS WAY TOWARDS EASTERN CANADA.
NOTABLY, OVER THE PAST FEW DAYS THE BERMUDA HIGH WEAKENED TO ITS
CURRENT MAGNITUDE OF 1023 MB. TONIGHT, THE GREAT LAKES LOW WILL
SUPPRESS THE HIGH AND ALLOW IT TO FURTHER WEAKEN AND SHIFT
EASTWARD. SYNOPTIC SCALE TROUGHING WILL DEVELOP OVER THE EASTERN
CONUS AND SLACKEN BREEZES TO GENTLE OVER THE CWA.
PAST SATURDAY, THE FORECAST UNCERTAINTY INCREASES RATHER QUICKLY.
WHILE TROUGHING DEVELOPS ON SATURDAY TO SUNDAY OVER THE MIDWEST,
MODEL ENSEMBLES SHOW A RIDGE BUILDING OVER THE NORTHERN PLAINS AND
LIFTING NORTHWESTWARD TO BE DIRECTLY NORTH OF A CUTOFF LOW. THESE
PATTERNS ARE REFERRED TO AS REX BLOCKS, AND ARE FREQUENTLY A
CHALLENGE FOR NUMERICAL MODELS AND FORECASTERS BOTH. THE KEYS, IN
RESPONSE, MAY OBSERVE ANYWHERE FROM GENTLE TO MODERATE BREEZES
NEXT WEEK. SHOWER CHANCES ARE ALSO VARIABLE. THE LOW HALF OF THE
POSSIBLE REX BLOCK COULD DIRECT A PLUME OF DEEP LAYER MOISTURE ON
SUNDAY TO MONDAY, OR IT MAY BE DELAYED UNTIL TUESDAY, OR NOT
APPEAR AT ALL. THE FURTHER QUESTION OF THUNDERSTORMS ALSO DEPENDS
ON HOW FAR SOUTH THE CUTOFF LOW MOVES, IF THE JET WILL BE ORIENTED
TO SUPPORT TROPOSPHERE-DEEP LIFTING AIR, AND IF THAT WOULD ALIGN
WITH THE MOISTURE PLUME. POINT BEING, UNCERTAINTY IN THE EXTENDED
FORECAST IS HIGH, AND AS WE BECOME CLOSER IN TIME TO THIS POSSIBLE
EVENT CONFIDENCE WILL INCREASE. AFTER THE POSSIBLE PERIOD OF
SHOWERS AT THE START OF NEXT WEEK, DRY WEATHER IS FORECAST TO
RETURN, ALBEIT WITH LIGHTER WINDS THAN THE PAST WEEK.
MARINE
ISSUED AT 154 PM EDT THU MAY 1 2025
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL WINDS DECREASE FOR ALL
FLORIDA KEYS COASTAL WATERS. FROM SYNOPSIS, A BROAD, THOUGH
WEAKENING, BERMUDA HIGH WILL SUSTAIN FRESH BREEZES ACROSS THE
WATERS SURROUNDING THE FLORIDA KEYS TONIGHT. BRIEF SLACKENING WILL
OCCUR TOMORROW AS BREEZES OSCILLATE BETWEEN STRONGER IN THE
EVENING AND WEAKER DURING THE DAY. A LOW PRESSURE SYSTEM MOVING
FROM THE GREAT LAKES INTO ONTARIO AND QUEBEC WILL WEAKEN THE
AFOREMENTIONED HIGH AND ALLOW WINDS TO DIMINISH TO GENTLE TO
MODERATE BREEZES LATE THIS WEEKEND.
AVIATION
(18Z TAFS)
ISSUED AT 154 PM EDT THU MAY 1 2025
VFR CONDITIONS WILL CONTINUE AT BOTH EYW AND MTH THROUGH THE TAF
PERIOD EVEN WITH FEW TO SCT SKIES BETWEEN FL035 AND FL050. ANY
LATE SHOWER ACTIVITY THAT MAY DEVELOP IS EXPECTED TO STAY FAR
ENOUGH AWAY FOR BOTH TERMINALS, SO TAFS WILL CONTINUE TO REFLECT
DRY WEATHER. BOTH TERMINALS WILL ALSO SEE SUSTAINED EASTERLY WINDS
10 TO 15 KNOTS, BUT GUSTS NEAR 20 KNOTS REMAIN IN EYW TAFS UNTIL
0100Z. AT MTH, GUSTS HAVE BECOME INFREQUENT, SO THEY HAVE BEEN
REMOVED FROM THE TAF PACKAGE.
CLIMATE
ON THIS DAY IN 1999, THE KEY WEST WFO MOVED INTO THE ADAM ARNOLD
ANNEX AT THE AIRPORT.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 75 84 75 85 / 10 10 10 10
MARATHON 75 82 75 84 / 10 10 10 10
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...AJP
AVIATION/NOWCASTS....DP
DATA ACQUISITION.....DP
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