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 with the approaching new moon.

- Rain chances will remain slightly above normal through Wednesday. - A drying trend will begin Wednesday night and Thursday, followed by the potential for lower humidity Sunday night or Monday.

DISCUSSION

Issued at 903 PM EST Tue Nov 3 2026 Water vapor imagery highlights a negatively tilted trough over the Mississippi River Valley. This trough will dig across the Gulf overnight and absorb the decaying trough immediately to the southwest of the Keys. The 00Z KKEY RAOB sampled more than 2.0" of PW, fairly uniform lower tropospheric southeasterlies, and near nil inhibition. In fact, the sounding and thermodynamic profile looks very much like a summer profile, except for the 50kt southwesterlies at 200 mb. The CIRA ALPW products suggest increasing moisture at all layers, so PW may actually be higher now and overnight. Southeasterly steering regimes are rather wet across the Keys as nocturnal confluence increases across the Straits of Florida. Given this analysis, we increased rain chances across the island chain to 50%, which is near the MOS consensus. This same pattern likely will persist into Wednesday, before a drying trend begins Wednesday night and Thursday.

PREVIOUS 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 903 PM EST Tue Nov 3 2026 High pressure offshore the Mid Atlantic States will maintain gentle to occasionally moderate east breezes through the evening followed by gradual slackening. Expect light to gentle breezes through the remainder of the week along with drier conditions. A surface high will develop across the Gulf beginning Friday, which may lead to brief nocturnal wind surges along the west coast of Florida and into the outer Gulf waters.

AVIATION

(00Z TAFS) Issued at 903 PM EST Tue Nov 3 2026 VCSH remains advertised through 12Z for both terminals, although TEMPOs are not included at this time. Any SHRA will be capable of brief periods of MVFR CIGS/VIS and convective wind gusts near 25 knots.

PRELIMINARY POINT TEMPS/POPS

Key West 76 84 76 83 / 50 10 20 10 Marathon 77 84 77 84 / 50 20 20 10

KEY WATCHES/WARNINGS/ADVISORIES

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

GM...None.