textproduct: Key West

KEY MESSAGES

- Below normal rain and thunder chances will continue through the overnight and into tomorrow morning.

- Rain and thunder chances will see a slight uptick sometime Wednesday evening as the larger scale unsettled weather pattern shifts. Confidence remains low as to how long this stretch of wet weather will linger for.

DISCUSSION

Issued at 1012 PM EDT Tue Oct 6 2026

A few streamer showers developed off the Lower Keys during the late afternoon and early evening. These, however, quickly dissipated once the sun set. At the same time, we did have drier air pivoting up from our south and southeast. This drier air remains over the area and was readily seen in tonight's upper air balloon launch. This has nearly halted any additional showers that have tried to develop in the last couple of hours. That being said, there are indications that relatively more moist air will return late in the overnight, closer to dawn on Wednesday. We could see some showers percolate around sunrise as it moves northeast across the Island Chain. Lastly, winds collapsed shortly after sunset with speeds generally 5 mph (4 knots) or less. This comes as no surprise as the Keys remain under an axis of dilation.

Elsewhere, in the Bay of Campeche, the National Hurricane Center began issuing advisories on newly formed Tropical Depression Nine as of 5 PM EDT. This system is progged to initially move east, then east-northeast, before taking a more northerly turn towards the central Gulf Coast States towards the end of the week. This system does not pose any direct threats to the Florida Keys at this time.

MARINE

Issued at 1012 PM EDT Tue Oct 6 2026

Light to occasionally gentle breezes have developed this evening and will likely persist through the overnight. The main changes will be winds clocking from the southeast and becoming more out of the southwest turns dawn on Wednesday. As this occurs, we could see breezes slightly freshen just prior to dawn and continuing through Wednesday. In addition, a plume of relatively better moisture will move in from the south and southwest towards dawn, which may result in some showers and possibly an isolated thunderstorm around sunrise. Otherwise, National Hurricane Center has begun advisories on what is now Tropical Depression Nine, located in the Bay of Campeche. This system is forecast to move slowly east, then east-northeast, before making a turn to the north towards the end of the week. This system poses no direct impacts to the Florida Keys coastal waters at this time.

AVIATION

(00Z TAFS) Issued at 1012 PM EDT Tue Oct 6 2026

VFR conditions expected through the overnight and into Wednesday. There could be some isolated shower or even a thunderstorm around sunrise. As it stands, confidence is too low to include mentions in the going TAF cycle.

PREV DISCUSSION

Issued at 244 PM EDT Tue Oct 6 2026 We continue to see generally quiet weather across the Florida Keys this afternoon. Temperatures have climbed into the upper 80s, and dew points are sitting in the mid to upper 70s. Usually the upper 70s is where things start to feel a little sticky or heavy, but we have had light breezes that have kept the air moving. Looking very close to home, we just so happen to be in an environment generally unfavorable for active weather. We are still lacking a source of meaningful lift, and the occasional light showers that we have seen on our KBYX radar have diminished quickly after development, telling us that the environment isn't necessarily conducive to support ongoing activity. A stray shower or two tonight cannot reasonably be ruled out, so we will continue to advertise a slight chance (nearly 10%) of showers and thunderstorms for now.

By tomorrow, rainfall chances increase as the front draped across northern Florida continues to slowly crawl into the peninsula. While a better moisture gradient will set up, the initial southerly flow may inhibit initial shower activity via Cuban shadow. Even though we have a 30% chance of rain tomorrow along the Keys, it will be a little less than that during the morning and a little more than that later tomorrow night. Since the gradient will be set up someone through central Florida, the best chances for active weather will be offshore to our north. There is still low confidence regarding just how much rain we could see as this will depend on how far south the boundary can get.

Ensemble guidance suggests that there is an opportunity for rain chances to diminish by sometime Friday, but the deepening cold front is going to interact a weak area of unsettled weather currently across central and eastern Cuba. This feature is noted on CIMSS vorticity analysis in the lower to middle levels. While there hasn't been significantly unsettled weather associated with it over the past couple of days, this additional instability could encourage additional activity through the weekend. Ensemble guidance is currently highlighting elevated winds, better chances for showers and thunderstorms, and cloudier skies. Where guidance is falling a little short is with respect to the timeframe where the best chances of active weather will be. Some ensemble members suggest measurable rainfall, particularly along the island chain, may arrive as early as late Friday night while other members suggest a lull through Saturday afternoon. It seems this will depend on how much interaction we get between the cold front, the arbitrary wave from Cuba, and Invest 92L in the western Gulf waters. We do want to note though that Invest 92L does not currently pose a threat to the Florida Keys, it may just serve as another source for moisture reinforcement over the weekend, and into early next week.

KEY WATCHES/WARNINGS/ADVISORIES

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