450
FXUS62 KKEY 021859
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
259 PM EDT FRI MAY 2 2025
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 242 PM EDT FRI MAY 2 2025
THE FIRST FRIDAY OF MAY OPENED ACROSS THE FLORIDA KEYS WITH MOSTLY
SUNNY SKIES, CLUSTERS OF SHALLOW SHOWERS OVER THE FAR WESTERN AND
EASTERN WATERS OF THE FLORIDA STRAITS, AND EAST TO SOUTHEASTERLY
MODERATE BREEZES. BREEZES ALONG THE REEF TRACT HAVE SLACKENED TO
THE 10 TO 15 KNOT RANGE AFTER SUNRISE. TEMPERATURES ALONG THE
ISLAND CHAIN ARE IN THE LOWER 80S WITH DEW POINTS STILL IN THE MID
TO UPPER 60S. SO FAR IT'S NOT MUGGY, BUT GIVE THE WEATHER TIME.
WET SEASON WILL BE UPON US SOONER THAN EXPECTED. TONIGHT, THE
GENERAL DIURNAL TREND FROM THE PAST WEEK STILL APPLIES; BREEZES
ARE FORECAST TO FRESHEN SLIGHTLY OVERNIGHT AND ANOTHER ROUND OF
LIGHT SPRINKLES COULD MOVE ACROSS THE KEYS.
SYNOPTIC SCALE FEATURES WILL BECOME MUCH MORE COMPLICATED OVER
THE WEEKEND. A BERMUDA HIGH WILL BOTH WEAKEN AND SHIFT EASTWARD
DURING THE NEXT FEW DAYS, ALLOWING THE PRESSURE GRADIENT TO
SLACKEN. SIMULTANEOUSLY, A MID LEVEL TROUGH WILL DIG INTO THE DEEP
SOUTH AND PHASE TOGETHER WITH WEAK SHORTWAVES BREAKING AWAY FROM
A WEAKENING CUTOFF LOW OVER THE FOUR CORNERS REGION. IN CONCERT
WITH THESE LAST COUPLE OF FEATURES, A PRONOUNCED RIDGE LOCATED
ALONG THE MONTANA AND CANADA BORDER WILL PROPAGATE WESTWARD. THE
RIDGE IS FORECAST TO BE DIRECTLY NORTH OF THE MIDLEVEL TROUGH BY
MONDAY, ESTABLISHING A REX BLOCK PATTERN OVER THE EASTERN HALF OF
THE COUNTRY.
DOWN IN THE FLORIDA KEYS, WE WILL NOT SEE THE MOST ACTIVE WEATHER
FROM THIS LESS COMMON BLOCKING SYSTEM, BUT THE FORECAST WILL BE
MUCH MORE UNCERTAIN. TIMING BLOCKING PATTERN FORMATION AND
CESSATION IS A CHALLENGE FOR BOTH METEOROLOGISTS AND NUMERICAL
MODELS. WHAT THEN, CAN BE SAID WITH CONFIDENCE?
STARTING OUT, WINDS WILL BE SAFELY BELOW SMALL CRAFT THRESHOLDS.
THE EXACT MAGNITUDE WILL VARY FROM MODEL RUN TO MODEL RUN, AND THE
CURRENT UPDATE TRENDED TOWARDS SLACKENING WINDS, AND (EXACT
BREEZES HERE NWPS WHY). SHOWER AND THUNDERSTORM COVERAGE WILL BE
THE MORE IMPORTANT CHALLENGE. THE TROUGH PORTION OF THE REX BLOCK
WILL DIRECT A TROPOSPHERE-DEEP PLUME OF MOISTURE ACROSS THE KEYS
FROM SATURDAY EVENING TO MONDAY MORNING. THE NOSE OF THE
SUBTROPICAL JET WILL BE POINTED AT THE KEYS DURING THIS SAME
PERIOD OF TIME. EXACTLY HOW STRONG THE TROUGH GETS AND HOW FAR
SOUTH IT MOVES WILL DETERMINE THUNDERSTORM COVERAGE.
AFTER MONDAY, DESPITE THE UNCERTAINTIES IN THE SYNOPTIC FORECAST
FOR CONUS, AND THERE ARE MANY, THE FLORIDA KEYS ARE EXPECTED TO
RETURN TO DRY CONDITIONS WITH AN OCCASIONAL GUST OF BREEZY
CONDITIONS. STAY TUNED AND WATCH THE RADAR TOMORROW AND SUNDAY!
MARINE
ISSUED AT 242 PM EDT FRI MAY 2 2025
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL WINDS DECREASE FOR THE
WATERS OF THE STRAITS OF FLORIDA. FROM SYNOPSIS, BREEZES WILL
SLOWLY BEGIN TO SLACKEN ACROSS THE FLORIDA KEYS WATERS THIS
WEEKEND. THE BERMUDA HIGH WILL STEADILY MOVE EAST AND ALLOW FOR
GENTLE TO MODERATE BREEZES FROM SATURDAY TO TUESDAY. A PLUME OF
MOISTURE FROM SUNDAY TO MONDAY SUPPORTS INCREASING SHOWER CHANCES
TO SCATTERED, AND EMBEDDED THUNDERSTORMS ARE LIKELY DURING THE
HEAVIEST RAINFALL. DRY BREEZES AND FRESHENING BREEZES ARE EXPECTED
FROM TUESDAY ONWARDS.
AVIATION
(15Z TAFS)
ISSUED AT 242 PM EDT FRI MAY 2 2025
VFR CONDITIONS WILL PREVAIL AT BOTH EYW AND MTH THROUGH THE TAF
PERIOD. AN OCCASIONAL ISOLATED SHOWER CANNOT BE RULED OUT THIS
AFTERNOON (CHANCE 10%), BUT THIS IS NOT MENTIONED IN THE TAFS DUE TO
THE UNLIKELIHOOD. WINDS WILL PERSIST FROM THE EAST-SOUTHEAST AT 10-
15 KNOTS.
CLIMATE
ON THIS DAY IN 1877 IN KEY WEST, THE DAILY RECORD LOW TEMPERATURE OF
63F WAS RECORDED. THIS IS ALSO TIED AS THE COLDEST TEMPERATURE EVER
RECORDED IN MAY. TEMPERATURE RECORDS FOR KEY WEST DATE BACK TO
1872.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 77 85 76 86 / 10 10 20 20
MARATHON 77 84 77 85 / 10 10 20 30
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...AJP
AVIATION/NOWCASTS....MC
DATA ACQUISITION.....AJP
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