textproduct: Key West

KEY MESSAGES

- Minor saltwater flooding of low elevation streets will continue through tomorrow morning due to higher high tides. Some storm drains will overflow. Boaters can expect less clearance under fixed bridges.

- Below normal rain and thunder chances will continue through at least Tuesday.

- Breezes will slowly slacken from gentle to moderate to light to gentle across the Keys waters by Monday.

DISCUSSION

Issued at 201 PM EDT Sun Oct 4 2026 Deep-layer ridging is centered almost directly overhead per CIMSS steering layer products. This continues to dominant our weather pattern today, promoting gentle to moderate east-southeasterly breezes and mostly sunny skies. 2" PWATs were measured on our 12Z KKEY RAOB, but deep anticyclonic flow aloft is greatly suppressing precipitation chances today. There have been brief isolated showers moving northwest across our waters, but there's a lack of vertical cloud growth noted on vis satellite imagery. Will maintain PoPs around 20% for the remainder of the day with a low chance of an isolated thunderstorm. Elsewhere along the island chain, the ridge will result in slightly above-normal temperatures this afternoon. Highs ranging from the mid to upper 80s combined with dewpoints in the upper 70s will produce heat index values in the upper 90s to around 102 degrees in spots along the Keys.

Little change is expected in the forecast for the next couple of days despite a few notable alterations to our surrounding synoptic pattern. The most notable of which will be the traversal of longwave troughing east across Canada and the Eastern CONUS tomorrow. This will force a cold front south through the Gulf Coast region. The front is forecast to stall east to west across the Florida Peninsula and northern to central Gulf tomorrow into Tuesday. To our east, inverted mid/upper-level troughing is progged to shift southwest over the Bahamas during this time. The Florida Keys will sit neatly in between these two features beneath ridging aloft, which will become increasingly squeezed and suppressed by midweek, while occasional pockets of dry air pass across the forecast area. As such, below normal rain and thunder chances are expected to persist for the next few days at least. The forecast later in the week will be dependent on the southern extent of the cold front as moisture content will be much higher along and ahead of the front. The axis of associated rainfall and lift will be very close to our Gulf waters on Wednesday. Global models vary on exactly where the front stalls, but would expect at least increasing rain and thunder chances by Wednesday night into Thursday, especially across the Gulfside waters north of the Island Chain, where there will be residual low-level troughing. Late in the week, we will need to monitor low pressure development west of the Yucatan, but there are no concerns to the Florida Keys at this time.

MARINE

Issued at 201 PM EDT Sun Oct 4 2026 A Coastal Flood Statement is in Effect for the Florida Keys island chain. Elsewhere, no watches, warnings, or advisories are in effect. From synopsis, Atlantic high pressure centered east of Bermuda will remain in place. This feature will maintain moderate east to southeasterly breezes today that will gradually slacken tonight through the first part of the week. In addition, relatively drier weather conditions have settled in, though isolated to scattered showers and occasional thunderstorms could still occur at times. A cold front is on track to stall across the Florida Peninsula and northern Gulf on Tuesday with the highest rain chances remaining north of the Florida Keys. This will promote a shift to south to southwesterly light to gentle breezes by midweek.

AVIATION

(18Z TAFS) Issued at 201 PM EDT Sun Oct 4 2026 Atlantic ridging remains extended across the area promoting southeasterly winds around 8 to 10 kts and mostly dry conditions. There is enough moisture to support a few showers, but coverage will be hindered by the dominant surface ridge, and if a shower occurs at a terminal it will be very brief. As such, expect VFR conditions to prevail through this TAF cycle.

PRELIMINARY POINT TEMPS/POPS

Key West 80 89 80 89 / 20 20 20 20 Marathon 80 89 80 88 / 20 20 20 20

KEY WATCHES/WARNINGS/ADVISORIES

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