textproduct: Key West

KEY MESSAGES

- Slight chance of showers and thunderstorms develop late tonight, with increasing shower and thunder chances through the week.

- Highs near 90 and dewpoints in the mid to upper 70s suggest afternoon heat indices will peak at 105 to 108 degrees.

MARINE

Issued at 323 PM EDT Mon Aug 24 2026

Generally gentle east to southeast breezes will prevail across the majority of the Florida Keys coastal waters. The exception at times will be the Southeast Gulf, where daytime heating across the mainland will lead to breezes decreasing briefly during the afternoons. Otherwise, expect breezes to peak overnight to gentle to moderate at times. As a ridge across the Atlantic slides westward, better moisture will pivot through, leading to a more active weather pattern through the later half of the week.

AVIATION

(18Z TAFS) Issued at 323 PM EDT Mon Aug 24 2026

VFR conditions expected to prevail. Watching for showers and potential thunderstorms to develop late overnight but confidence is not high enough to put mentions in the current TAF at this time.

FORECAST

The western periphery of the ridge over the Atlantic will maintain modest control of the Keys for the next day or two. It will start to gain stronger influence across the area heading towards mid week. Therefore, expect another day of slight chance of showers and thunderstorms as well as tonight. Since the flow is still somewhat weak, the potential exists for another cloud line today. Other than that, some hi-res model guidance remains rather insistent on most of the convection developing just north of the Chain later this morning heading into the afternoon hours. Most guidance suggests the activity waning after that with not much anticipated for the late afternoon and evening hours. However, we still cannot rule out an isolated shower or thunderstorm during that time. As the ridge slowly builds into the Keys through the week, it will be met with increasing moisture. Therefore, increasing chances for showers and thunderstorms are expected as the week progresses. Latest indications are for this activity not to be all that rambunctious, but rather more of the garden variety type convection. Perhaps a storm or two becomes strong enough to warrant a Special Marine Warning, etc.

The interesting time frame actually looks to be towards the latter half of the week. More in the way of upper level support is expected which would give any showers and storms more ferocity. Therefore, it is during this time frame when the more widespread warnings or statements might be needed as well as more widespread shower and storm activity.

The aforementioned high pressure will continue to build across the region through the week and into the weekend. This will result in a more stout east to southeast flow with peaking breezes during the evening and overnight hours and lulling during the morning and afternoons. In addition, expect daytime highs near 90 degrees with overnight lows in the lower to mid 80s and dew points in the mid to upper 70s. Of course, temperatures may fall into the upper 70s where any showers and storms move over.

TROPICS: The National Hurricane Center (NHC) continues to monitor 2 areas across the Atlantic Ocean with none of these systems currently posing a threat to the Keys. The area across the Eastern Tropical Atlantic now has a 10% chance of development over 48 hours and 50% chance of development over the next 7 days.

PRELIMINARY POINT TEMPS/POPS

Key West 83 90 83 90 / 10 20 50 50 Marathon 83 91 83 91 / 20 30 50 50

KEY WATCHES/WARNINGS/ADVISORIES

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