734
FXUS62 KKEY 130838
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
438 AM EDT SUN JUL 13 2025
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 437 AM EDT SUN JUL 13 2025
IT HAS BEEN A GENERALLY CALM NIGHT ACROSS THE FLORIDA KEYS. KBYX
RADAR IS NOT DETECTING ANY SHOWER ACTIVITY CURRENTLY, THOUGH,
EARLIER IN THE NIGHT, IT DID DETECT SOME SHOWERS OVER THE EASTERN
STRAITS OF FLORIDA. GOES EAST NIGHTTIME MICROPHYSICS IMAGERY SHOWS
MOSTLY CLEAR SKIES ACROSS THE KEYS FOR THE TIME BEING WITH THE
ONLY CLOUDS OF NOTE BEING SOME LOW LEVEL CUMULUS. TEMPERATURES
ALONG THE ISLAND CHAIN ARE IN THE LOWER TO MID 80S WITH DEW POINTS
IN THE UPPER 70S. BIG PINE KEY HAS ACTUALLY DIPPED TO 79 DEGREES
AS A RESULT OF SOME RADIATIONAL COOLING THAT HAS TAKEN EFFECT
OVERNIGHT. HIGH PRESSURE OVER THE ATLANTIC EXTENDS ITS WESTERN
PERIPHERY WESTWARD THROUGH FLORIDA AND INTO THE WESTERN GULF. THIS
IS RESULTING IN MARINE PLATFORMS AROUND THE KEYS OBSERVING EAST TO
SOUTHEAST BREEZES OF 5 TO 10 KNOTS AND ISLAND CHAIN COMMUNITIES
OBSERVING 5 TO 10 MPH.
FORECAST
HIGH PRESSURE REMAINS IN CONTROL OF THE FLORIDA KEYS WEATHER
THROUGH TONIGHT. GOES EAST TOTAL PRECIPITABLE WATER (TPW) PRODUCTS
SHOWS PWAT VALUES RANGING FROM 1.75 INCHES TO 1.95 INCHES
THROUGHOUT THE AREA. THEREFORE, EVEN THOUGH WE HAVE HIGH PRESSURE
LARGELY IN CONTROL, THERE IS PLENTY OF MOISTURE THROUGHOUT THE
AREA. THIS CAN LEAD TO THE THREAT FOR SOME SHOWERS AND EVEN
THUNDERSTORMS AT ANY POINT IN TIME. THEREFORE, ABOVE NORMAL RAIN
CHANCES REMAIN IN PLACE FOR TODAY AND TONIGHT WITH 40% AND 50%
RESPECTIVELY. ANY ACTIVITY TODAY IS LARGELY EXPECTED TO FORM OFF
ANY RESIDUAL BOUNDARIES OR MESOSCALE PROCESSES. FOR TONIGHT,
SHOWERS AND THUNDERSTORMS THAT FORM ON THE MAINLAND ARE EXPECTED
TO DRIFT SOUTHWARD POTENTIALLY IMPACTING PARTS OF THE ISLAND
CHAIN, ESPECIALLY THE UPPER KEYS. ANY STORMS WILL BE CAPABLE OF
PRODUCING GUSTY WINDS, FREQUENT LIGHTNING, AND HEAVY DOWNPOURS.
MONDAY THROUGH WEDNESDAY, THE FOCUS WILL MAINLY BE ON THE 20%
AREA FOR TROPICAL DEVELOPMENT WITHIN THE NEXT 7 DAYS THAT THE NHC-
NATIONAL HURRICANE CENTER HAS HIGHLIGHTED ACROSS THE NORTHERN
GULF. AT MOST, A WEAK AREA OF LOW PRESSURE IS EXPECTED TO SLOWLY
MEANDER SOUTHWARD FROM OFF THE GEORGIA COASTLINE AND THEN
RETROGRADE BACK TO THE WEST THROUGH MID WEEK. AS A RESULT, BOUTS
OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TO BE INITIATED EACH DAY
AS THE SYSTEM SLOWLY MOVES THROUGH THE AREA. MOST OF THE ACTIVITY
THE KEYS COULD SEE MAY INITIALLY FORM ON THE MAINLAND AND THEN
DRIFT SOUTHWARD THROUGH THE KEYS. ANY STORMS WILL BE CAPABLE OF
PRODUCING STRONG GUSTY WINDS, LOCALLY HEAVY RAINFALL, AND FREQUENT
LIGHTNING. DUE TO THIS, THE FORECAST HAS BEEN DRASTICALLY CHANGED
FROM PREVIOUS PACKAGES. THERE IS NOW A 60% CHANCE FOR RAIN FROM
MONDAY THROUGH TUESDAY WITH 50% FOR TUESDAY NIGHT AND WEDNESDAY.
THUNDER HAS ALSO BEEN INCREASED FROM SLIGHT CHANCE TO CHANCE AS
CONFIDENCE INCREASES FOR A MUCH WETTER AND STORMIER PERIOD FOR THE
EARLY TO MIDDLE PART OF THE WEEK. THE WEATHER PREDICTION CENTER
(WPC) HAS THE KEYS HIGHLIGHTED IN A SLIGHT RISK (LEVEL 2 OUT OF 4)
FOR THE MONDAY THROUGH TUESDAY TIME PERIOD.
A MORE TYPICAL SUMMER TIME PATTERN RETURNS FOR MID TO LATE WEEK
AND INTO THE FIRST HALF OF THE WEEKEND. HIGH PRESSURE OVER THE
ATLANTIC BUILDS INTO FLORIDA BRINGING A RETURN TO THE EAST TO
SOUTHEASTERLIES AND MOISTURE UNDULATIONS AROUND THE WESTERN
PERIPHERY OF THE HIGH. AS A RESULT, EXPECT DECREASING RAIN CHANCES
WITH 40% FOR WEDNESDAY NIGHT BEFORE RAIN CHANCES RETURN TO AROUND
NORMAL FOR THE REMAINDER OF THE EXTENDED WHICH IS NEAR 30%.
MARINE
ISSUED AT 437 AM EDT SUN JUL 13 2025
THERE ARE CURRENTLY NO WATCHES, WARNINGS, OR ADVISORIES IN EFFECT
ACROSS THE FLORIDA KEYS COASTAL WATERS. FROM SYNOPSIS, HIGH
PRESSURE REMAINS IN CONTROL ACROSS MUCH OF THE FLORIDA KEYS
THROUGH TONIGHT. THIS WILL RESULT IN EAST TO SOUTHEAST BREEZES
EARLY THIS MORNING BECOMING VARIABLE. WEAK LOW PRESSURE TRIES TO
DEVELOP IN THE VICINITY OF FLORIDA HEADING THROUGH THE FIRST HALF
OF THE WEEK. INITIALLY, THE KEYS WILL BE ON THE SOUTHERN FRINGE IN
A COL REGION RESULTING IN MAINLY VARIABLE BREEZES THROUGH MONDAY
NIGHT. AS THE WEAK LOW PRESSURE AREA SHIFTS TO THE WEST AND HIGH
PRESSURE BUILDS IN BEHIND, BREEZES WILL FRESHEN BECOMING SOUTHEAST
TO SOUTH AT FIRST, BEFORE BECOMING EAST TO SOUTHEAST FOR MID TO
LATE WEEK. ALSO, EXPECT INCREASING COVERAGE OF SHOWERS AND
THUNDERSTORMS FOR THE EARLY TO MIDDLE PART OF THE WEEK.
AVIATION
(06Z TAFS)
ISSUED AT 437 AM EDT SUN JUL 13 2025
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT EYW AND MTH THROUGH THE
TAF PERIOD. SOME PASSING SHOWERS AND THUNDERSTORMS ARE POSSIBLE,
WHICH WOULD LIKELY RESULT IN BRIEF PERIODS OF MVFR CONDITIONS.
TIMING AND COVERAGE OF ANY SHOWERS THAT DO APPROACH THE TERMINALS
WILL BE ADDRESSED VIA TAF AMENDMENT AS NEEDED. WINDS WILL REMAIN
FROM THE SOUTHEAST AT 5 TO 10 KNOTS INTO THIS AFTERNOON, THEN
SLACKEN AND BECOME VARIABLE. HIGHER GUSTS WILL BE POSSIBLE WITH
PASSING SHOWER AND THUNDERSTORM ACTIVITY.
CLIMATE
ON THIS DAY IN 2023, THE DAILY RECORD HIGH TEMPERATURE OF 99F WAS
RECORDED AT MARATHON. THIS IS ALSO TIED FOR THE WARMEST
TEMPERATURE EVER RECORDED FOR THE MONTH OF JULY, OR ANY MONTH, FOR
THE MARATHON AREA. THE DAILY RECORD WARM LOW TEMPERATURE OF 86F
WAS ALSO RECORDED AT MARATHON IN 2023. TEMPERATURE RECORDS FOR
MARATHON DATE BACK TO 1950.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 91 81 90 79 / 20 30 50 60
MARATHON 89 80 88 78 / 40 50 60 70
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...MJV
AVIATION/NOWCASTS....MC
DATA ACQUISITION.....MC
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