textproduct: Key West

KEY MESSAGES

- Minor coastal flooding will continue through the next several days, especially in the Upper Keys. Minor to moderate coastal flooding may return across the Keys heading into the weekend with the approaching new moon.

- Rain chances will remain slightly above normal today with island cloud lines possible. - A drying trend will begin tonight and Thursday, followed by the potential for lower humidity Sunday night or Monday.

DISCUSSION

Issued at 203 PM EST Wed Nov 4 2026

The KBYX radar has certainly come to life over the last couple of hours. Convection that began across the far eastern waters continues while new convection has developed and moved southwest off Cape Sable. Meanwhile, a cloud line has developed across the Middle and Lower Keys, with the Lower Keys showing a more robust and healthy cloud line. Showers are developing within both cloud lines with the heaviest precipitation occurring from Lower Sugarloaf Key out Cosgrove Shoal Light. These cloud lines are thanks to a shallow layer of northeasterlies just off the surface and a moist low level.

In the short term, a low level ridge axis currently lies just offshore of the Eastern Seaboard and extends southwestward across the Florida Peninsula and near the Keys. This will continue to provide the region with a northeast to east wind through this evening and into the overnight. Meanwhile, in the mid levels a ridge across the Gulf Basin will gradually slide eastward and a broad area of higher pressure will develop to our west. This will maintain initially a northeast surface wind across the Keys through Friday. By Friday night through the weekend, as the surface high pressure gains better definition, we will see winds back to the northwest and north and surge at times.

Beyond Sunday the forecast confidence remains lower than average. A potent weather system currently out across the eastern Pacific has yet to move onshore and thereby be properly sampled by our upper-air radiosonde network. This is evident is the large spread between the GFS and ECMWF. The GFS has the system phasing with the Subtropical Jet next week. This would allow a potent weather system to dive southeast and move across the southeast U.S., with a trailing front pushing through the Keys. The ECMWF on the other hand has no such phasing occurring and thereby does not show a potent weather system. Instead, it shows more of a zonal pattern developing with weak, broad troughing occurring late next week.

Needless to say, models will continue to drastically change until the system moves inland across the Pacific NW and is able to be better sampled by direct observations. Stay tune!

MARINE

Issued at 203 PM EST Wed Nov 4 2026

Breezes will generally be slackening through Friday as a high pressure along the Eastern Seaboard is squeezed and eroded by flanking weather systems. By Friday a broad surface high will develop across the Gulf Basin which may support a backing of the winds from the northwest to north and allow for brief nocturnal surges, especially this weekend. Forecast confidence remains low beyond Sunday and have tried to take a middle of the road approach with the winds and seas for now. Mariners are urged to check back later this week for updates!

AVIATION

(18Z TAFS) Issued at 203 PM EST Wed Nov 4 2026

Current iteration of the cloud line is diminishing and with it the showers that developed within this line. There is a small chance the cloud line may reinvigorate before sunset with potentially another round of showers. Otherwise, drier air will filter in, lowering rain/thunder chances. Surface winds will continue out of the northeast to east at 10 knots or less.

PRELIMINARY POINT TEMPS/POPS

Key West 76 83 76 82 / 10 0 0 0 Marathon 77 84 76 83 / 10 0 0 0

KEY WATCHES/WARNINGS/ADVISORIES

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