690
FXUS62 KKEY 270851
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
451 AM EDT MON JUL 27 2026
..NEW DISCUSSION, MARINE, AVIATION
KEY MESSAGES
- PEAK RAIN AND THUNDER CHANCES ARE EXPECTED TODAY WITH DECREASING
RAIN CHANCES EXPECTED FOR TONIGHT, THOUGH STILL ABOVE NORMAL AS
THE ACTIVE PATTERN CONTINUES.
- LIGHT TO GENTLE WEST TO NORTHWEST BREEZES EXPECTED THIS MORNING
BECOMING MAINLY WESTERLY THIS AFTERNOON AND TONIGHT.
- HEAT INDICES MAY APPROACH 105 TO 110 DEGREES EACH AFTERNOON FOR
SOME FLORIDA KEYS ISLAND COMMUNITIES, ESPECIALLY IN THE UPPER
KEYS.
DISCUSSION
ISSUED AT 445 AM EDT MON JUL 27 2026
CIMSS PRODUCTS SHOWS THE KEYS REMAIN IN BETWEEN TWO MASSIVE
RIDGES WITH ONE CENTERED OVER THE CENTRAL NORTH ATLANTIC AND THE
OTHER ACROSS THE SOUTH-CENTRAL UNITED STATES. THE KEYS ARE ON THE
EASTERN PERIPHERY OF THE RIDGE OVER THE SOUTH-CENTRAL STATES
RESULTING IN NORTHWESTERLY FLOW DOWN THE FLORIDA PENINSULA. A
TROUGH REMAINS IN PLACE JUST OFF THE EASTERN SEABOARD IN BETWEEN
THE TWO RIDGES AND FLORIDA REMAINS ON THE BACKSIDE OF THIS TROUGH.
AT THE SURFACE, HIGH PRESSURE IS CENTERED ACROSS THE CENTRAL GULF
WITH THE KEYS ON THE EASTERN SIDE OF THIS HIGH ALONG WITH A
SURFACE TROUGH OVER THE FLORIDA PENINSULA. MARINE OBSERVATION
PLATFORMS SURROUNDING THE ISLAND CHAIN ARE RECORDING NORTHWEST
BREEZES OF 5 TO 10 KNOTS AS A RESULT. KBYX RADAR WAS QUIET UP
UNTIL AN HOUR OR TWO AGO WHEN SHOWERS AND THUNDERSTORMS DEVELOPED
THROUGHOUT THE FLORIDA KEYS COASTAL WATERS, ESPECIALLY IN THE
VICINITY OF THE LOWER KEYS. GOES 19 NIGHTTIME MICROPHYSICS
IMAGERY SHOWS PARTLY CLOUDY SKIES THROUGHOUT THE KEYS WITH A
MIXTURE OF UPPER LEVEL AND LOW LEVEL CLOUDS. TEMPERATURES ALONG
THE ISLAND CHAIN ARE IN THE LOWER TO MID 80S AND DEW POINTS ARE IN
THE MID 70S.
FORECAST
SURFACE TROUGHING REMAINS ACROSS THE EASTERN SEABOARD AND THE
WESTERN NORTH ATLANTIC TODAY AND TONIGHT. THIS IS IN BETWEEN TWO
MASSIVE RIDGES WITH ONE ACROSS THE CENTRAL NORTH ATLANTIC AND THE
OTHER ACROSS THE SOUTH-CENTRAL UNITED STATES. THIS WILL KEEP
INCREASED MOISTURE ACROSS THE AREA FOR TODAY AND TONIGHT LEADING
TO WELL ABOVE NORMAL RAIN CHANCES (70%). SLIGHTLY DRIER AIR
MOVES IN TONIGHT RESULTING IN RAIN CHANCES DROPPING TO SLIGHTLY
ABOVE NORMAL (40%). RAIN CHANCES PEAK TODAY AS MOISTURE MAXIMIZES
AND THE GREATEST FORCING IS OVERHEAD. ANOTHER TROUGH IS EXPECTED
TO SWING DOWN FROM CANADA SLIDING ACROSS THE GREAT LAKES,
NORTHEAST, AND MID-ATLANTIC. THIS WILL REINFORCE THE CURRENT
TROUGHING ALREADY IN PLACE. AT THE SURFACE, A FRONTAL BOUNDARY
WILL REMAIN DRAPED ACROSS NORTH FLORIDA AND GEORGIA FOR THE NEXT
SEVERAL DAYS. THIS IS QUITE UNUSUAL FOR THIS TIME OF THE YEAR. DUE
TO THIS, IT WILL KEEP A FAIRLY UNSETTLED PATTERN ACROSS NORTH TO
CENTRAL FLORIDA AS THE MOISTURE FOCUSES ACROSS THIS AREA. DRIER
AIR IS EXPECTED TO MOVE INTO THE KEYS DUE TO THE RIDGE ACROSS THE
ATLANTIC LEADING TO DECREASING RAIN CHANCES. THE HEAT WILL
BECOME THE MAIN STORY AGAIN ESPECIALLY FROM MID WEEK ONWARD.
DAYTIME HIGHS WILL BE IN THE LOWER 90S AND OVERNIGHT LOWS IN THE
LOWER 80S WITH SOME MID 80S FROM MID TO LATE WEEK. DEW POINTS IN
THE MID TO UPPER 70S WILL LEAD TO HEAT INDEX VALUES OF 105 TO 110
DEGREES.
LIGHT TO GENTLE WEST TO NORTHWEST BREEZES ARE EXPECTED TODAY
BEFORE SHIFTING TO THE SOUTHWEST TO WEST BY TUESDAY. BREEZES WILL
FRESHEN TO GENTLE TO MODERATE AS THE HIGH ACROSS THE ATLANTIC AND
THE FRONT ACROSS FLORIDA ACT IN TANDEM WITH ONE ANOTHER LEADING TO
AN INCREASED PRESSURE GRADIENT, ESPECIALLY FOR MID WEEK. AFTER MID
WEEK, THE GRADIENT RELAXES SOME AND BREEZES RELAX BACK TO LIGHT TO
GENTLE.
MARINE
ISSUED AT 445 AM EDT MON JUL 27 2026
THERE ARE CURRENTLY NO WATCHES, WARNINGS, OR ADVISORIES IN EFFECT
ACROSS THE FLORIDA KEYS COASTAL WATERS. FROM SYNOPSIS, TROUGHING
JUST OFF THE EASTERN SEABOARD WILL REMAIN FOR THE NEXT DAY OR SO
BEFORE ANOTHER TROUGH SWINGING SOUTHEASTWARD THROUGH THE GREAT
LAKES AND INTO THE NORTHEAST REINFORCES THE TROUGH ACROSS THE EAST
COAST. AT THE SURFACE, THIS WILL RESULT IN A FRONTAL BOUNDARY
REMAINING DRAPED ACROSS THE NORTHERN FLORIDA/GEORGIA FOR MUCH OF
THIS WEEK. INITIALLY, EXPECT WEST TO NORTHWEST LIGHT TO GENTLE
BREEZES BEFORE SHIFTING TO THE SOUTHWEST TO WEST BY TUESDAY.
BREEZES WILL BECOME GENTLE TO MODERATE TOWARDS MID WEEK BEFORE
SLACKENING BACK TO LIGHT TO GENTLE BREEZES BY LATE WEEK.
AVIATION
(06Z TAFS)
ISSUED AT 445 AM EDT MON JUL 27 2026
VFR CONDITIONS ARE EXPECTED TO MOSTLY PERSIST AT BOTH EYW AND MTH
TERMINALS THROUGH THE TAF PERIOD. NEAR SURFACE WINDS WILL REMAIN
MOSTLY WEST TO NORTHWEST THROUGH THIS EVENING BEFORE SHIFTING MORE
TO THE SOUTHWEST TO WEST. WELL ABOVE NORMAL RAIN AND THUNDER
CHANCES ARE EXPECTED TODAY. SINCE THERE HAS BEEN DECENT AGREEMENT
ACROSS THE GUIDANCE, VCTS WAS INCLUDED IN BOTH TAFS BEGINNING AT
27/12Z. THE BEST CHANCE TIME FOR SHOWER AND THUNDERSTORM ACTIVITY
APPEARS TO BE DURING THE DAYLIGHT HOURS TODAY. ANY SHOWERS AND
THUNDERSTORMS WILL BE CAPABLE OF REDUCING CIGS AND VIS TO MVFR
CONDITIONS, AS WELL AS PRODUCING GUSTY WINDS, AND OCCASIONAL
LIGHTNING STRIKES. THERE IS ALSO THE LOW PROBABILITY FOR BRIEF
IFR CONDITIONS.
CLIMATE
ON THIS DAY IN 2024, THE DAILY RECORD RAINFALL OF 2.32" WAS
RECORDED IN KEY WEST. RAINFALL RECORDS FOR KEY WEST DATE BACK TO
1871.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 89 82 90 82 / 60 30 40 20
MARATHON 89 81 91 82 / 70 50 50 20
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...MJV
AVIATION/NOWCASTS....MJV
DATA ACQUISITION.....MJV
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