textproduct: Key West

KEY MESSAGES

- Island cloud line formation will be possible in the late morning or afternoon hours through the weekend.

- Waterspouts will be possible with any developing island cloud line.

- Conditions will remain seasonably warm and muggy, with heat indices approaching near 100F each afternoon through early next week.

AVIATION

(18Z TAFS) Issued at 131 PM EDT Thu Jun 11 2026 VFR conditions will prevail at both island terminals through 18z Friday afternoon. The best chances for any shower or thunderstorm activity in the vicinity of the terminals will occur in late afternoon hours today, then again in the late morning or afternoon hours on Friday, associated with possible island cloud line formation. Light east to southeast breezes will become light and variable at times after 18z each day.

DISCUSSION

Issued at 1011 AM EDT Thu Jun 11 2026 The 12z sounding at KEY sampled a unidirectional boundary layer profile, characterized by decent 700-850 mb dew point depressions and limited 100 mb mean-layer inhibition. GOES-19 visible satellite imagery continues to highlight relatively thick cirrus advecting from the south, debris from a quasistationary, broad Central American Gyre feature. Arrived earlier this morning to our CWA nearly echo free from meteorological returns. Since then, convective initiation has commenced over portions of the Middle and Upper Keys and the adjacent marine zones.

For the balance of today, a tough rainfall forecast. Current reasoning suggests convective cycles will be short, with rapid periods of waxing and waning owed to decaying flow. However, there are several boundaries looking across the Keys marine zones, and conditions are also somewhat ripe for island cloud formation, including nearshore waterspouts. However, the aforementioned 850-700 mb moderate dry air along with the overshadowing cirrus will likely limit any significant convective outbreak. Have elected to keep the inherited 30-40% PoPs through this afternoon. No changes proposed.

MARINE

Issued at 1011 AM EDT Thu Jun 11 2026 No watches, warnings, or advisories are in effect for the Florida Keys Coastal Waters. From synopsis, a weak high pressure system in the west- central North Atlantic will slide eastward over the next several days, merging with another high pressure system in the eastern North Atlantic. This will support light to gentle east to southeast breezes gradually veering to the southeast to south through the weekend and into early next week.

PRELIMINARY POINT TEMPS/POPS

Key West 81 89 81 90 / 10 20 10 20 Marathon 81 89 80 89 / 10 20 10 20

KEY WATCHES/WARNINGS/ADVISORIES

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