textproduct: Key West

KEY MESSAGES

- Coastal flooding will continue through the next several days, especially in the Upper Keys.

- Rain chances will remain slightly above normal through night. Locally heavy rainfall, especially when coincident with high tides may exacerbate coastal flooding impacts.

- Rain chances will diminish over the following few days to near or below normal.

DISCUSSION

Issued at 256 PM EST Tue Nov 3 2026

After a burst of showers and thunderstorms earlier in the afternoon, activity has quickly begun to quiet back down. Convection for the most part has either stayed offshore and to the west of the Lower Keys or over the mainland. Winds have been stubborn to decrease and are holding in the 10 to 15 knot range across all of our marine platforms.

In the short term, the Keys will remain between a weakening, elongated upper level cut-off low to our west and a ridge pinned against the Carolina coastline. This is maintaining a broad area of convergence across the area with a moist low level flow. This will continue to feed at least low chances (30 to 40%) for additional showers and thunderstorms through the overnight. By Wednesday the upper level reflection of the cut-off low will become poorly defined, while the low to middle level becomes absorbed by an incoming trough from the northwest. This will allow the ridge to briefly build westward and sharpen on Wednesday. This new orientation will allow for a narrow band of convergence to develop across the Upper Keys where we expect the highest chances for more showers and thunderstorms.

By late Wednesday into Thursday, the approaching upper level trough will sweep through, helping to scour out what moisture remains. At the same time, drier air in the lower levels will round the ridge along the Carolinas. The combination of the two sources of dry air will effectively shutdown precip chances for the end of the week and into the early part of the weekend.

Beyond Saturday, the weather becomes chaotic and messy and our confidence drops considerably. This is because the next potential weather maker for the Keys has yet to move ashore off the Pacific and thereby be properly sampled by the upper air radiosonde network. The weather for next hinges on what happens. The GFS and ECMWF generally show a trough moving onshore Thursday from the PacNW and then diving southeast towards Florida by early next week. Where they differ is on the speed, orientation (a deep trough with two vort maxes, or a cut-off low), strength (owing back to the orientation), and placement. There are a lot of variable at play here and we won't have a better idea of next week until later this week. For now, have opted a middle ground approach with increasing winds and moisture starting Sunday and going through at least Tuesday.

MARINE

Issued at 256 PM EST Tue Nov 3 2026

Gentle to occasionally moderate east to southeast breezes continue this afternoon and will gradually slacken through the overnight. Surface pressure across the region will lessen allowing for breezes to undergo a brief cycle of peaks and lulls Wednesday through Friday. Thereafter, there is the potential for a surface high to develop across the Gulf Basin. This in turn would induce a a nightly northwest wind surge along the west coast of Florida over the weekend. Confidence on this is medium at this time. Otherwise, drier conditions will return starting Wednesday evening and continue through the upcoming weekend. Watching a complicated a messy system to take shape early next week which may have sweeping changes for the region.

AVIATION

(18Z TAFS) Issued at 256 PM EST Tue Nov 3 2026

VFR conditions expected outside of any passing shower. Confidence on when or if showers restart is too low to include mentions to the current TAF cycle. Rain/thunder chances will quickly diminish from west to east during the day on Wednesday and may even stay east of the MTH terminal. Otherwise, expect an E to SE wind near 10 knots, gradually backing to the east and slackening slightly.

PRELIMINARY POINT TEMPS/POPS

Key West 76 84 76 83 / 30 10 20 10 Marathon 77 84 77 84 / 30 20 20 10

KEY WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Advisory until 5 AM EST Wednesday for FLZ076.

GM...None.