textproduct: Key West

KEY MESSAGES

- Quiet weather will continue through the afternoon and into this evening. - Moderate to occasionally fresh south to southwest breezes will become light to gentle southwesterlies tonight. Aside from convective influences, winds will then clock northwest, then north as a weak boundary presses southward across the Keys.

- A wetter and thundery pattern will begin moving in tonight. Shower and thunderstorms chances are expect to peak Sunday night and gradually taper off early next week. Confidence remains low regarding total rainfall amounts.

MARINE

Issued at 355 PM EDT Sat May 2 2026

Gentle to moderate southwest breezes continue this afternoon and may slacken briefly to light to gentle in the late evening, before freshening overnight. This will be caused by a weakening of the pressure gradient initially, followed by a tightening of the gradient as a front appraoches from the north. Frontal passage is expected during the morning on Sunday with a quick uptick in northerly breezes in the wake. Gentle to moderate breezes will persist on Monday as a high pressure quickly moves across the Southeast U.S. As this high moves across the Atlantic, expect a return to east to southeast breezes.

AVIATION

(18Z TAFS) Issued at 355 PM EDT Sat May 2 2026

VFR conditions expected through the remainder of the afternoon and this evening. Showers and isolated thunderstorms will begin developing within the southerly flow during the overnight. Meanwhile, ongoing convection will be sinking southeast across the Gulf towards the island chain. This second area of convection is leading to higher uncertainty on exact timing and placement. However, chances look to be best after 03Z/3rd with MVFR conditions likely developing. Brief IFR conditions will be possible within heavier activity.

PREV DISCUSSION

Issued at 400 AM EDT Sat May 2 2026

A mid latitude trough will amplify across the eastern United States this weekend, with assistance of a couple of shortwave troughs. While lower level flow will become confluent with increasing moisture, at least for today and this evening, there will be enough vestiges of earlier low level ridging to keep convection at bay. An early morning wind surge will wear off today, with breezes becoming light to gentle out of the southwest. Expect slightly above normal temperatures today with dew points holding in the mid 70s.

Guidance suggests that an old frontal boundary will migrate southwards into Central and South Florida tonight. The nearly phased trough aloft will result in broad diffluence aloft while confluence previously mentioned lower level confluence brings in much higher moisture and increasing instability. Forecast soundings indicate precipitable water will climb to just shy of 2 inches by Sunday morning. In addition, the HRRR suggests that active convection along the frontal boundary will be capable of driving an active outflow boundary southwards into the Keys late tonight. This is not an unreasonable solution, however uncertainty is high. Have nudged rain chances to high chance for tonight.

An additional southern stream shortwave trough will ride through the mid latitude trough late Sunday, adding support to an already unstable and very wet column. In addition, the weak frontal boundary will press southwards in fits and starts through the Keys. Rain chances will continue to climb through the remainder of the weekend, likely peaking Sunday night. Considerable cloudiness, effects of convection, and weak flow, and the passage of the weak boundary will likely result in temperatures dipping to only a couple of degrees below normal with dew points slipping to just above 70.

Through the first half of the week the upper mid latitude trough will push out into the Atlantic, followed up by ridging building across the Gulf of America. This will allow surface ridging to establish itself across the southeast and Florida, bringing in a more usual light to gentle east to southeasterly flow. Expect near to slightly above normal temperatures with dew points ranging in the lower 70s. Rain and thunder chances will steadily taper off to slight.

PRELIMINARY POINT TEMPS/POPS

Key West 77 85 74 84 / 50 60 60 20 Marathon 78 85 74 83 / 50 60 70 30

KEY WATCHES/WARNINGS/ADVISORIES

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