textproduct: Key West

KEY MESSAGES

- Very warm and humid conditions will continue across the Florida Keys, raising the risk for heat-related illnesses through the weekend. - Rain and thunder chances remain be increasing starting today and peaking Sunday through Monday.

- Breezy conditions are possible by early next week.

DISCUSSION

Issued at 446 AM EDT Sat May 16 2026

A high pressure cell moving into the Atlantic off the Carolinas is beginning to exert it's presence across the Florida Keys. This has resulted in winds clock around from the east and southeast and gradually increasing through the overnight. Meanwhile, moisture is slowly pushing back this morning in thanks to a southeast to south mean flow in the boundary layer. This has begun interacting with a lingering boundary out across the Straits of Florida where isolated showers and thunderstorms have developed over the past couple of hours.

As the high continues to build across the Atlantic, we expect winds to continue to strengthen through the day. Meanwhile, the low-level steering flow will initially becoming increasingly southerly. This flow is not a favorable wind direction for all day shower potential. We will see some showers this morning with the initial surge of moisture and instability but then quiet by the late morning and afternoon. The exception will be the Upper Keys, where winds will be more southeasterly and more favorable to keep scattered showers and isolated thunderstorms going at times.

As the high slides further east, the steering flow will become southeast allowing for better moisture transport and increase our rain chances overnight through Sunday. The high's position by Sunday night through Monday night will allow breezes to peak and we can expect a brief period of breezy conditions. This will also aid in mass/moisture convergence and rain chances look to peak Sunday night into Monday. Thereafter, the high will continue to slide further east out across the Atlantic and the pressure gradient will relax some. In addition, pockets of drier air will pivot through at times, leading to a generally drying trend for the second half of next week.

No air mass changes expected. Daily high temperatures will range from 85 to 90 degrees and could be a couple degrees warmer late in the week. Dew points will hold in the mid 70s, the combination of which will result in heat index values hovering around 100 degrees during the peak daytime heating.

MARINE

Issued at 446 AM EDT Sat May 16 2026

Light southeast breezes this morning will freshen to gentle to moderate east to southeast breezes by the early afternoon. Breezes are then expected to further freshen over the weekend, peaking Sunday night through Monday night with moderate to fresh breezes expected. As high pressure moves further east across the Atlantic, the gradient will weaken slightly and breezes will slacken back to gentle to moderate. Meanwhile, an increase in moisture will lead to greater coverage of showers and thunderstorms over the next several days.

AVIATION

(06Z TAFS) Issued at 446 AM EDT Sat May 16 2026

VFR conditions expected today outside of any passing showers. The best chances for showers will be concentrated near and to the west of the EYW terminal, mainly this morning. Expecting a lull in the activity by the late morning and early afternoon with shower coverage increasing again late overnight into Sunday. Light and variable winds will become east to southeast and steadily increase through the day.

PRELIMINARY POINT TEMPS/POPS

Key West 91 80 91 81 / 20 30 40 40 Marathon 87 80 87 81 / 20 40 50 40

KEY WATCHES/WARNINGS/ADVISORIES

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