483
FXUS62 KKEY 110216
AFDKEY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KEY WEST FL
1016 PM EDT THU SEP 10 2026
..NEW DISCUSSION, MARINE, AVIATION, PREV DISCUSSION
KEY MESSAGES
- MOISTURE WILL LINGER ACROSS THE REGION THROUGH THE START OF THE
WEEKEND, SUPPORTING RAIN AND THUNDERSTORM CHANCES.
- THE PRIMARY THREAT FOR ANY STRONGER THUNDERSTORMS WILL BE
DANGEROUS LIGHTNING STRIKES. WHEN THUNDER ROARS, GO INDOORS. IF
ON A BOAT, STAY LOW, OR GO BELOW.
- HEAT INDEX VALUES WILL RANGE FROM 100-108 DEGREES DAILY WITH
LITTLE RELIEF FROM THE MUGGY CONDITIONS OVERNIGHT. KNOW THE
SIGNS OF HEAT STRESS, TAKE FREQUENT BREAKS, AND STAY HYDRATED.
DISCUSSION
ISSUED AT 1016 PM EDT THU SEP 10 2026
ROUNDS OF SHOWERS AND THUNDERSTORMS CONTINUE TO FORM ACROSS THE
FLORIDA KEYS WATERS THIS EVENING. RESIDENTS IN THE LOWER KEYS
COULD LOOK OFF TOWARDS THE OUTER GULF WATERS AND SEE EXTREMELY
VIGOROUS LIGHTNING COMPLEXES NEAR THE TOWERS. THE KKEY 00Z
SOUNDING SAMPLED AN ENVIRONMENT WITH A PWAT SAFELY ABOVE THE 90TH
PERCENTILE FOR THE DAY. MOISTURE WAS PLENTIFUL THROUGH 600 MB, AND
THE AMOUNT OF CAPE CALCULATED WAS IN EXCESS OF 3000 J/KG. IT IS
NOT SHOCKING THAT THUNDERSTORMS CAPABLE GENERATING GUSTS IN EXCESS
OF 34 KNOTS WERE ABLE TO FORM. OUTSIDE OF SHOWERS, GENTLE TO
MODERATE BREEZES PERSIST ALONG THE REEF. WINDS ARE GENERALLY EAST
TO SOUTHEAST. OVERNIGHT, EXPECT THE WEATHER TO BE SOMEWHAT SIMILAR
TO WHAT HAS BEEN OBSERVED THE PAST FEW DAYS. LOWS ACROSS THE KEYS
ARE ON TRACK TO BE IN THE LOWER 80S, HUMIDITY ELEVATED, WITH A
CHANCE OF SHOWERS AND THUNDERSTORMS.
WATER VAPOR SATELLITE IMAGERY FROM GOES EAST, AS WELL AS THE
700-500 ADVECTED LAYER PRECIPITABLE WATER, HIGHLIGHT A SHALLOW
PLUME OF DRIER AIR MOVING TOWARDS THE FLORIDA KEYS WATERS LATE
TONIGHT. THERE ARE A COUPLE OF FORECAST CHALLENGES THAT COME FROM
THIS FEATURE. THE DRY LAYER MAY LIMIT SHOWER DEVELOPMENT TONIGHT,
OR THE INTRUSION OF DRY AIR WILL INCREASE THE AMOUNT OF AMBIENT
INSTABILITY IN THE ENVIRONMENT. CONVECTIVE MODELS HAVE NOT BEEN
RESOLVING SHOWERS AND THUNDERSTORMS OVERNIGHT, BUT PRIOR MODEL
RUNS ALSO DID NOT SHOW DEVELOPMENT OF THE PREVIOUSLY MENTIONED
THUNDERSTORMS OVER THE GULF. LOW TO MID LEVEL WINDS IN MODEL
ENSEMBLES WERE SLIGHTLY ANTICYCLONIC, AND THUS OPTING TO LEAVE
POPS AT 30 PERCENT OVERNIGHT. THE LULL IN SHOWER ACTIVITY IS NOT
EXPECTED TO STAY FOR LONG. MOISTURE IS ABOUT TO RETURN AFTER
SUNRISE, SO BRACE FOR ANOTHER DAY OF HEARING THUNDERSTORMS OVER
THE WATER.
MARINE
ISSUED AT 1016 PM EDT THU SEP 10 2026
NO WATCHES, WARNINGS, OR ADVISORIES ARE IN EFFECT FOR THE FLORIDA
KEYS COASTAL WATERS.
FROM SYNOPSIS: RIDGING ACROSS THE SOUTHEASTERN UNITED STATES AND
FLORIDA WILL MAINTAIN GENTLE TO MODERATE EAST TO SOUTHEASTERLY
BREEZES. EXPECT BREEZES TO PEAK IN THE EVENING AND OVERNIGHT WHILE
LULLING DURING THE DAY. A SERIES OF LOWER LEVEL MOISTURE SWATHES
WILL SUPPORT PERIODS OF ELEVATED RAIN AND THUNDER CHANCES THROUGH
THE REMAINDER OF THE WEEK AND INTO THE WEEKEND.
AVIATION
(00Z TAFS)
ISSUED AT 1016 PM EDT THU SEP 10 2026
VFR CONDITIONS WILL PREVAIL AT EYW AND MTH FOR THE UPCOMING
PERIOD. NEAR SURFACE WINDS NEAR 10 KNOTS ARE EXPECTED FOR BOTH
TERMINALS. THE ENVIRONMENT IS PRIMED FOR SHOWERS AND
THUNDERSTORMS, BUT THE TIMING OF RAINFALL AT BOTH SITES IS VERY
UNCERTAIN. STATISTICAL GUIDANCE AND CONVECTIVE MODELS SUGGEST 15Z,
AROUND 11 AM, AS THE MOST LIKELY TIME VCSH WOULD BECOME
WIDESPREAD.
KEY WATCHES/WARNINGS/ADVISORIES
FL...NONE.
GM...NONE.
PUBLIC/MARINE/FIRE...AJP
AVIATION/NOWCASTS....AJP
DATA ACQUISITION.....DM
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