697
FXUS62 KKEY 110833
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
433 AM EDT TUE MAR 11 2025
..NEW DISCUSSION, MARINE, AVIATION
DISCUSSION
ISSUED AT 400 AM EDT TUE MAR 11 2025
A LATE SEASON COLD FRONT BLASTED THROUGH THE FLORIDA KEYS
YESTERDAY DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
IN THE WAKE OF THE FRONTAL PASSAGE, BREEZY CONDITIONS CONTINUE
ACROSS THE ISLAND CHAIN. THE NORTHWESTERLY FLOW HAS USHERED IN A
CONTINENTAL, MODIFIED- POLAR AIR MASS. ALL AVAILABLE STATIONS
ACROSS THE KEYS ARE REPORTING TEMPERATURES IN THE MID TO UPPER 60S
AT THIS EARLY MORNING HOUR, WITH DEW POINTS IN THE MID TO UPPER
50S AT MOST LOCATIONS. NIGHTTIME-DERIVED SATELLITE IMAGERY
HIGHLIGHTS MOSTLY CLEAR SKIES ACROSS THE ENTIRE FORECAST AREA,
WITH KBYX NOT DETECTING ANY PRECIPITATION FEATURES.
THE STRENGTHENING AREA OF LOW PRESSURE THAT DRAGGED THE
AFOREMENTIONED FRONT WILL CONTINUE TO PROGRESS EASTWARD OFF THE
CAROLINA COASTLINE AND INTO THE NORTH ATLANTIC OVER THE NEXT
COUPLE OF DAYS. MEANWHILE, A WEAK AREA OF HIGH PRESSURE CENTERED
IN THE VICINITY OF THE GULF COAST WILL TRAVERSE EASTWARD,
EVENTUALLY LANDING NORTH OF THE BAHAMAS. AFTER A COOL DAY ON TAP
TODAY OWED TO THE NORTHERLY STEERING FLOW, TEMPERATURES WILL
MODERATE RATHER STEADILY OVER THE NEXT SEVERAL DAYS, AS FLOW
AROUND THE HIGH VEERS TO AN EASTERLY, THEN EVENTUALLY
SOUTHEASTERLY DIRECTION. GLOBAL NUMERICAL WEATHER PREDICTION
FORECAST SOUNDINGS DEPICT A VERY DRY TROPOSPHERIC PROFILE THROUGH
THE END OF THE WORK WEEK, AND NIL RAIN CHANCES CONTINUE TO BE
ADVERTISED.
A SECONDARY HIGH WILL BUILD IN THE CENTRAL NORTH ATLANTIC OVER THE
WEEKEND, WHICH WILL SUPPORT A TIGHTENED GRADIENT WIND FIELD. A
COMBINATION OF SPEED CONVERGENCE AND INCREASED MOISTURE FLUXES IN
THE SOUTHEASTERLY FLOW AT LEAST WARRANTS MENTION OF SLIGHT
MEASURABLE RAIN CHANCES OVER THE WEEKEND, ALTHOUGH MOST
COMMUNITIES WILL LIKELY REMAIN DRY. VERY WARM CONDITIONS ARE ON
TAP FOR THE WEEKEND, WITH HIGHS LIKELY TOPPING OUT IN THE LOWER
80S.
MOST EXTENDED ENSEMBLE MEAN GLOBAL GUIDANCE SUPPORTS A LONGWAVE
TROUGH DEEPENING IN THE GREAT PLAINS LATE IN THE WEEKEND, WITH A
SERIES OF SHORTWAVES RIDING ALONG THE LONGWAVE FEATURE. IN THIS
SCENARIO THIS TIME OF YEAR, A SEVERE WEATHER OUTBREAK IS A GOOD
BET FOR THE SOUTHEAST AND MID-ATLANTIC. HOWEVER, EARLY
GUIDANCE SUGGESTS THE ASSOCIATED FRONTAL FEATURE LARGELY BEING
DEFLECTED NORTHWARD AND AWAY FROM SOUTH FLORIDA, KEEPING THE KEYS
GENERALLY VOID OF ANY CONVECTIVE OUTBREAK. WITH THAT SAID, A
BACKDOOR FRONTAL PASSAGE IS CERTAINLY POSSIBLE AS THIS FEATURE
LIFTS NORTHWARD FOR EARLY NEXT WEEK, ALTHOUGH THERE IS CERTAINLY
PLENTY OF TIME TO NAIL OUT THESE DETAILS.
MARINE
ISSUED AT 400 AM EDT TUE MAR 11 2025
LATEST MARINE-BASED SURFACE OBSERVATIONS INDICATE NORTHWESTERLY
WINDS REMAIN GENERALLY SUSTAINED NEAR 20 KNOTS, WITH FREQUENT
GUSTS NEAR 25 KNOTS. A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
ALL FLORIDA KEYS MARINE ZONES. FROM SYNOPSIS, FRESH TO STRONG
NORTHWESTERLY BREEZES IN THE WAKE OF THE COLD FRONTAL PASSAGE
YESTERDAY AFTERNOON AND EVENING WILL GRADUALLY SLACKEN TODAY. HIGH
PRESSURE OVER THE GULF WILL SLIDE EASTWARD THROUGHOUT THE WORK
WEEK, WITH GENTLE TO MODERATE BREEZES CLOCKING AROUND TO THE
NORTHEAST, THEN EAST, AND THEN TO SOUTHEAST. AS A SECOND, STRONGER
HIGH BUILDS IN THE WESTERN NORTH ATLANTIC, SOUTHEASTERLY BREEZES
WILL FRESHEN FOR SATURDAY AND SATURDAY NIGHT.
AVIATION
(06Z TAFS)
ISSUED AT 400 AM EDT TUE MAR 11 2025
VFR AND DRY CONDITIONS WILL PREVAIL IN THE WAKE OF A FRONTAL PASSAGE
AT BOTH MTH AND EYW THROUGH THE TAF PERIOD, THOUGH VERY BRIEF
PERIODS OF MVFR CIGS ARE POSSIBLE BEFORE SUNRISE THIS MORNING. WINDS
WILL REMAIN GUSTY FROM THE NORTHWEST THROUGH SUNRISE, THEN VEER TO
THE NORTHWEST TO NORTH AND GRADUALLY DIMINISH INTO THE EARLY
AFTERNOON.
CLIMATE
ON THIS DAY IN 1986, THE DAILY RECORD RAINFALL OF 1.40" WAS OBSERVED
AT MARATHON. RAINFALL RECORDS FOR MARATHON DATE BACK TO 1950.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 73 67 77 70 / 0 0 0 0
MARATHON 73 67 77 70 / 0 0 0 0
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR GMZ031>035-
042>044-052>055-072>075.
PUBLIC/MARINE/FIRE...BT
AVIATION/NOWCASTS....MC
DATA ACQUISITION.....MC
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