textproduct: Key West

KEY MESSAGES

- Coastal flooding will continue to gradually decrease over the weekend, but receding rates will be slow, especially in the Upper Keys.

- Gentle to moderate northeasterly breezes may see an uptick by tonight, but are expected to slacken again tomorrow.

- A wet, stormy period is expected tonight through Monday. Locally heavy rainfall, if timed with high tides, may exacerbate coastal flooding hazards.

DISCUSSION

Issued at 1010 AM EDT Sat Oct 31 2026 Twenty four hours makes quite a difference for weather across the Florida Keys. Yesterday, weather across the Keys was reminiscent of winter conditions due to north-northeasterly winds, persistent decks of stratus clouds, and lack of energy available for convection. In contrast, this morning the KBYX radar detected widely scattered showers were streaming across the waters surrounding the Florida Keys. Easterly breezes were sustaining dew points in the mid to upper 70s. The morning 12Z KKEY sounding sampled an environment with ample instability, deep layers of moisture below 600 mb, and prevailing easterly winds. Advected Layer PWAT products detected a similar concentration of moisture throughout the atmosphere. Layers from the surface to 700 mb were heavily saturated, while moisture was present but not increasing in the 700 to 500 mb layer. Based on current conditions, we are keeping the 40% chance of showers in the forecast. Breezes are not likely to freshen to Small Craft Advisory levels, but Small Craft Should Exercise Caution headlines may be required tonight.

The primary focus this afternoon is, once again, coastal flooding. Thankfully, we are on the receding side of the tide cycle. Tide heights at Key West harbor did not rise into Major flood category levels, and tidal stations at Vaca Cut and Grassy Key also did not measure Major flood levels. Thus, we are electing to take the Middle Keys out of the Coastal Flood Warning. The problem is that any showers that do move over the island chain, if timed to a high period in the tide cycle, could exacerbate coastal flooding hazards. Remember to avoid flooded roadways and take precautions, because stagnant salt water does bad things to vehicles.

MARINE

Issued at 1010 AM EDT Sat Oct 31 2026 There are no watches, warnings, or advisories in effect for the Florida Keys local waters. Significantly higher than normal high tides will result in reduced clearance under fixed bridges around times of high tide, so mariners are encouraged to keep that in mind.

From synopsis: a broad area of high pressure over the eastern United States will sustain moderate to fresh breezes across the Florida Keys waters this weekend. Small Craft Should Exercise Caution headlines may be required for portions or all marine zones tonight. Breezes are on track to slacken tomorrow, but elevated winds along the Florida Peninsula will generate higher northerly swell for the waters south of the Upper Keys. After the initial higher winds tonight, breezes will slacken during the weekend. Light to gentle breezes are possible midweek. Shower chances are expected to peak tomorrow through Monday with drier conditions during the middle of the week.

AVIATION

(12Z TAFS) Issued at 1010 AM EDT Sat Oct 31 2026 Widely scattered, occasionally heavy showers will keep VCSH in the TAFs through the day at EYW and MTH. Prevailing VFR conditions may be interrupted by short lived MVFR VIS and CIGs throughout the TAF period due to brief SHRA moving over the terminals. Surface winds, outside of showers, are on track to remain easterly near 10 knots.

CLIMATE

On this day in Keys Weather History, in 1999, the daily record rainfall of 4.05" was recorded in Marathon. Precipitation records for Marathon date back to 1950.

PRELIMINARY POINT TEMPS/POPS

Key West 84 76 83 76 / 50 50 70 70 Marathon 84 77 83 76 / 40 60 70 70

KEY WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Warning until 5 AM EDT Sunday for FLZ076.

Coastal Flood Advisory until 5 AM EDT Sunday for FLZ077-078.

GM...None.