953
FXUS62 KKEY 180206
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1006 PM EDT FRI JUL 17 2026
..NEW DISCUSSION, MARINE, AVIATION
KEY MESSAGES
- LIGHT TO GENTLE VARIABLE BREEZES WILL ASSUME A SOUTHEASTERLY
DIRECTION OVERNIGHT.
- HEAT WILL BE THE PRIMARY WEATHER CONCERN THROUGH THE REST OF THE
WEEK AS INDICES MAY APPROACH 108 TO 110 DEGREES IN THE AFTERNOON
FOR PORTIONS OF THE ISLAND CHAIN.
- ROUNDS OF SAHARAN AIR LAYER WILL CONTINUE TO STREAM ACROSS OUR
AREA THIS WEEK INTO NEXT WEEK, KEEPING RAIN AND THUNDER CHANCES
SLIGHT AT BEST.
DISCUSSION
ISSUED AT 903 PM EDT FRI JUL 17 2026
WHILE WE TYPICALLY ADDRESS OUR LOCAL WEATHER CONDITIONS IN THE
EVENING UPDATE, WE CAN'T LOOK PAST THE ELEPHANT IN THE ROOM. THE LOW
SPINNING OVER THE SOUTHEASTERN GULF STICKS OUT LIKE A SORE THUMB
ON VIRTUALLY ALL FORMS OF DATA INGESTION THIS EVENING. SOME OF THE
TALLEST SHOWERS ARE BEING DETECTED ON OUR KBYX RADAR AS SATELLITE
IMAGERY SHOWS THE LOW SLOPPILY SPINNING OUTSIDE OF OUR MARINE
ZONES. CIMSS MEAN LAYER IMAGERY SHOWS THE HEART OF THE LOW IS
MOSTLY "STACKED", MEANING WE CAN SEE IT REFLECTED IN BOTH THE
UPPER, MIDDLE, AND LOWER LEVELS, AND SEEMS TO SLOWLY BE TRACKING
DEEPER INTO THE SOUTHEASTERN GULF. CLOSER TO HOME, A COL REGION
HAS SET UP, AND HAS HELPED TO PROVIDE A FEW BOUNDARIES FOR SHOWERS
AND THUNDERSTORMS. WE DON'T HAVE MANY IN SITU SURFACE OBSERVATIONS
TO CLEARLY DEFINE THE WIND FIELD, BUT LOWER LEVEL TROPOSPHERIC
MAPS VIA SPC FROM THIS EVENING SEEM TO REFLECT THE LIGHT AND
VARIABLE WIND PATTERN ASSOCIATED WITH THE CENTER OF A COL ACROSS
OUR AREA. CONVERGENCE ALONG THE SOUTHWEST TO NORTHEAST AXIS OF THE
COL HAS RESULTED IN SOME SHOWERS AND THUNDERSTORMS THIS EVENING.
THE 00Z KKEY SOUNDING FROM THIS EVENING WASN'T IMPRESSIVE WITH
RESPECT TO SUPPORTING ACTIVE WEATHER. WHILE THERE WAS 1700 J/KG OF
ML CAPE CALCULATED, THERE WAS ALSO A MODEST AMOUNT OF INHIBITION
AROUND 850 MB. THE MOISTURE PROFILE ALSO ISN'T OVERTLY IMPRESSIVE
WITH 1.48" OF PWAT CALCULATED, JUST ONE HUNDREDTH OF AN INCH
HIGHER THAN THE TENTH PERCENTILE. ALL OF THIS IS TO SAY THAT A FEW
SHOWERS AND THUNDERSTORMS COULD OCCUR OVERNIGHT, PARTICULARLY OVER
OUR WESTERN MARINE ZONES WHERE WE CAN STILL SEE SOME CONVERGENCE
BOUNDARIES. THE INHERITED SLIGHT CHANCE OF SHOWERS AND
THUNDERSTORMS SEEMS JUSTIFIED. AS THE TROUGHING IS EXPECTED TO DIG
JUST A LITTLE DEEPER, WE MAY LOSE OUR COL FEATURE AND OUR SURFACE
WINDS WILL RESUME A SOUTHEASTERLY DIRECTION.
TEMPERATURES ALONG THE ISLAND COMMUNITIES ARE CURRENTLY IN THE MID
80S. WITH JUST A LITTLE BIT OF MID TO HIGHER CLOUD COVER FILLING
IN, SOME OF THE "TRAPPED" HEAT WILL KEEP OVERNIGHT LOWS FROM
COOLING DOWN MUCH MORE. NO ADJUSTMENTS ARE NEEDED TO THE INHERITED
FORECAST PACKAGE.
MARINE
ISSUED AT 903 PM EDT FRI JUL 17 2026
A WEAK SURFACE TROUGH NEAR THE NORTHEASTERN GULF AND NORTHERN
FLORIDA WILL MAINTAIN A SPLIT RIDGE PATTERN ACROSS FLORIDA FOR THE
NEXT SEVERAL DAYS. THE KEYS WILL EITHER BE WITHIN A COL REGION
SOUTH OF THE BROAD SURFACE TROUGH, OR WITHIN THE SOUTHERN QUADRANT
OF THE TROUGH. THUS, BREEZES ACROSS THE FLORIDA KEYS WILL BE
VARIABLE AT TIMES, OR TAKE ON A SOUTHERLY COMPONENT. OUR FORECAST
TAKES THE MIDDLE GROUND AND IS AN AVERAGE OF THE TWO SCENARIOS.
AVIATION
(00Z TAFS)
ISSUED AT 903 PM EDT FRI JUL 17 2026
BOTH ISLAND TERMINALS WILL SEE VFR CONDITIONS PREVAIL THROUGH THE
TAF PERIOD, BUT ISOLATED POCKETS OF SHOWERS NEAR EYW MAY LEAD TO
OCCASIONAL MVFR CIGS AS THIS ACTIVITY BREAKS UP. NO LONG STANDING
IMPACTS ARE EXPECTED FROM ANY CATEGORICAL CHANGES. INITIALLY LIGHT
AND VARIABLE SURFACE WINDS WILL EVENTUALLY BECOME SOUTHEASTERLY
NEAR 5 KNOTS. BOTH AIR FIELDS SHOULD STAY DRY WITH ANTICIPATED
ACTIVITY WELL TO THE NORTH AND WEST OF THE KEYS.
PRELIMINARY POINT TEMPS/POPS
KEY WEST 84 91 83 91 / 20 20 20 20
MARATHON 83 92 83 92 / 20 20 20 20
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...DP
AVIATION/NOWCASTS....DP
DATA ACQUISITION.....11
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