392
FXUS62 KKEY 030818
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
418 AM EDT SAT MAY 3 2025
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 418 AM EDT SAT MAY 3 2025
A SUBTLE MOISTURE INCREASE WE HAVE BEEN WATCHING ACROSS THE
SOUTHWESTERN NORTH ATLANTIC HAS FINALLY BEGUN CREEPING INTO OUR
EASTERNMOST CWA. THERE IS ENOUGH MOISTURE THAT SOME LIGHT SHOWERS
RESIDE IN THE EAST TO SOUTHEAST FLOW THIS MORNING. MOST OF THESE
SHOWERS ARE CURRENTLY AIMED AT THE UPPER KEYS AND PORTIONS OF THE
MIDDLE KEYS. MEANWHILE, A BROAD AREA OF HIGH PRESSURE HAS MOVED
SLIGHTLY FURTHER EAST ACROSS THE ATLANTIC OVERNIGHT. THIS HAS LEAD
TO A WINDS BECOMING MORE SOUTHEASTERLY. OTHERWISE, TEMPERATURES
CURRENTLY ARE IN THE MID 70S AND DEW POINTS CONTINUE TO HOLD IN
THE MID 60S FOR NOW.
MOISTURE INITIALLY WILL BE CONFINED TO OUR EASTERN AREAS THIS
MORNING. AS THE 850-700 MB FLOW BECOMES MORE SOUTHERLY, WE COULD
SEE MOISTURE ADVECT FROM OUR SOUTH. HOWEVER, THAT WIND CAN ALSO
WORK AGAINST US AND KEEP RAIN CHANCES NEAR NIL. WITH THAT BEING
SAID, HAVE ELECTED TO KEEP RAIN CHANCES AT SLIGHT (10 PERCENT)
FOR TODAY. IF CUBA CAN FIRE OFF SHOWERS AND THUNDERSTORMS TODAY,
THEY COULD DRIFT INTO THE OUTER STRAITS OF FLORIDA WATERS. GIVEN
THE LIGHT STEERING FLOW AND THE DEEP LAYER SUBSIDENCE IN PLACE, IT
WILL BE HARD TO SUSTAIN THUNDERSTORMS ONCE THEY MOVE AWAY FROM
THEIR SOURCE REGION.
MEANWHILE, MOISTURE WILL BEGIN ADVECTING IN FROM THE WEST AND
NORTHWEST ALONG A DECAYING FRONTAL BOUNDARY. SAID BOUNDARY IS
ASSOCIATED WITH A QUASI CUT- OFF LOW THAT IS MOVING THROUGH THE
LOWER OHIO VALLEY. AS THE BOUNDARY SAGS SOUTHEAST IT WILL FURTHER
DECAY AND THERE ARE INDICATIONS THAT THE MOISTURE WILL GRADUALLY
ERODE WITH IT. THIS IS REALLY THROWING A WRENCH INTO THE FORECAST.
WHILE LOW LEVEL MOISTURE (850 MB AND BELOW) WILL POOL ACROSS THE
AREA, THE DRYING IN THE 700-500 MB LAYER IS CONCERNING. IN
ADDITION, THE INSTABILITY NOTED ON YESTERDAY'S FORECAST SOUNDING
HAS BACKED OFF. THERE APPEARS TO BE A WEAK SHORTWAVE RIPPLING
THROUGH THE FLOW BUT IT REMAINS TO BE SEEN WHAT INFLUENCE IT WILL
HAVE ON OUR SENSIBLE WEATHER. FOR NOW WILL KEEP RAIN CHANCES
SLIGHTLY BELOW GUIDANCE GIVEN THE HIGHER THAN USUAL UNCERTAINTY.
OTHERWISE, WE ARE NOT EXPECTING ANY PATTERN CHANGES. THE
AFOREMENTIONED FRONTAL BOUNDARY WILL STAY TO OUR NORTH. THE ONLY
INFLUENCE IT WILL HAVE WILL BE TO WEAKEN THE RIDGE AXIS ACROSS OUR
AREA. THIS WILL LEAD TO A BRIEF PERIOD OF LIGHTER WINDS SUNDAY
INTO MONDAY. THE RIDGE WILL THEN RESTRENGTHEN WITH THE RIDGE AXIS
LIFTING NORTHWARD ACROSS THE KEYS AND INTO SOUTH FLORIDA. THIS
WILL SEE THE RETURN OF FRESHENING EASTERLY BREEZES. IN ADDITION,
WE CAN EXPECT DEW POINTS TO BEING CLIMBING INTO THE LOWER 70S WITH
MUGGY CONDITIONS LIKELY TO RETURN.
MARINE
ISSUED AT 418 AM EDT SAT MAY 3 2025
BREEZES WILL SLOWLY BEGIN TO SLACKEN ACROSS THE FLORIDA KEYS
WATERS LATER THIS MORNING. A BERMUDA HIGH WILL STEADILY MOVE
EAST, ALLOWING FOR A BRIEF PERIOD OF LIGHT TO GENTLE BREEZES
SUNDAY THROUGH MONDAY AFTERNOON. MOISTURE WILL STEADILY CLIMB,
SUPPORTING AN INCREASED THREAT FOR SHOWERS AS WELL AS AN ISOLATED
THREAT FOR THUNDERSTORMS BEGINNING TONIGHT AND CONTINUING INTO
MONDAY. FRESHENING EASTERLY BREEZES RETURN TUESDAY ALONG WITH
DRIER CONDITIONS.
AVIATION
(12Z TAFS) ISSUED AT 418 AM EDT SAT MAY 3 2025
VFR CONDITIONS WILL PREVAIL AT THE ISLAND TERMINALS TODAY. BRIEF
SPELLS OF SUB VFR CONDITIONS WILL BE POSSIBLE DUE TO SCATTERED
STRATOCUMULUS WITH EMBEDDED ISOLATED SHOWERS. SURFACE WINDS WILL BE
GENTLE OUT OF THE EAST TO SOUTHEAST.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 84 76 84 76 / 10 20 20 20
MARATHON 84 77 84 77 / 10 20 30 30
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...LIW
AVIATION/NOWCASTS....11
DATA ACQUISITION.....11
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