textproduct: Key West

KEY MESSAGES

- Deep tropical moisture will linger near our area over the next day or so, keeping rain chances above normal.

- Drier air associated with a weak early season cold front will arrive late this week and into the weekend. This has the potential to push rain chances down below normal this weekend.

- Increasing northeasterly swell in the wake of the cold front will allow seas to build up to 5 feet by the end of the week and into the weekend, especially in the easternmost Straits of Florida.

DISCUSSION

Issued at 917 PM EDT Wed Sep 23 2026

A wetter than normal weather pattern remains across the Keys, but is finally tapering off this evening. An amplified upper level trough remains across the eastern United States with a weak tail reaching far southward through the eastern Gulf and into the Yucatan. Meanwhile a lower level trough and associated copious moisture has shifted east of the Florida Peninsula and is now aligned across the northern Bahamas and eastern Florida Straits. Recent radar imagery depicted a broad area of cyclonic flow remains across our area. This evenings sounding indicated a very high 2.5 inch of precipitable water, with no inhibition, and modest CAPE. As a result of the above, shower activity across our area has been scattered through the evening, but less coverage than in recent days and weaker with considerably fewer thunderstorms.

Through the overnight period the portion of the upper level trough north of our area will swing eastward towards the Atlantic Coast while the remaining southern half weakens and shears out. Meanwhile, the lower level trough will remain across the northern Bahamas and eastern Florida Straits, keeping the area of potential excessive rainfall off to our east. With that said, deep layered moisture will remain high and background flow will remain cyclonic. All this along with the environment remaining uncapped with marginal CAPE justifies holding onto above normal PoPs through the overnight period. Surface winds will remain light and quite varying due to the weak cyclonic flow wobbling around our area. Expect overnight lows in the upper 70s to near 80 with dew points holding in the mid 70s.

MARINE

Issued at 917 PM EDT Wed Sep 23 2026

A weak area of cyclonic flow will meander aimlessly across our area through the overnight period. As a result, breezes will remain light and variable on Keys waters. Expect isolated to scattered showers with a few thunderstorms possible.

AVIATION

(06Z TAFS) Issued at 119 AM EDT Thu Sep 24 2026

Weak surface troughing combined with high amounts of tropical moisture over the Keys will support at least VCSH near EYW for the next several hours. However, the trough and associated upper- level support is slowly shifting east of the area which should limit potential for aviation impacts for much of this TAF cycle. SHRA/TSRA development is expected to remain just south or east of the terminals with lower confidence near the Island Chain. Will be watching trends closely, and will amend if necessary. Otherwise, as the trough shifts east, sfc winds will gradually become north-northwesterly by 12Z.

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...None.