textproduct: Key West

KEY MESSAGES

- Major coastal flooding in the Upper Keys and minor to moderate coastal flooding in the Lower to Middle Keys is ongoing, especially around high tide.

- Small Craft Advisory remains in effect for all the Florida Keys coastal waters. A Gale Watch is in effect for all the Florida Key coastal waters from early Monday morning through early Tuesday morning. - Fast-moving showers and isolated thunderstorms are moving through the area, and will continue through at least Tuesday night. Any of this activity will be capable of producing stronger wind gusts.

DISCUSSION

Issued at 355 PM EDT Sun Oct 25 2026 A couple of rather amplified features over the United States and the Atlantic basin are complicating the weather across the Florida Keys. First, water vapor satellite imagery from GOES East highlights a cutoff low spinning over the Bahamas and eastern Cuba. The dry side of this low has kept subsident air focused over the Keys during the first half of the weekend. Over the eastern US, a well-established ridge has continued to sustain surface high pressure systems over the southeastern states. The problem is that a surface high currently over Delaware, Maryland, and Virginia is on track to sink southwesterly. At the same time, the cutoff low is beginning to direct enhanced moisture towards South Florida and the Keys. Thus, weather tonight will rapidly become busy. The sharpening pressure gradient will be able to support fresh to strong breezes while shallow showers move across the Keys waters at anywhere from 15 to 25 knots. A shallow shower near Long Key this afternoon was able to generate a 33 knot gust. Tonight, expect winds and short lived showers to be the most notable features for those along the island chain.

The short term forecast became very complicated rather quickly. Statistical and convective models give near equal support for and against near gale conditions over the nearshore waters and the island chain. The pressure gradient is on track to intensify and support frequent gale force gusts east of the Florida Peninsula during the first half of the week. However, models are suggesting the cold air advection supporting the gale force winds will remain north of the Keys. While there is high confidence that near gale force conditions will be observed over the offshore waters, the island chain and southern Florida will be able to reduce wind speeds across the nearshore waters. Reduced cold air advection heading towards the Keys means less mixing to the surface, and this is before taking showers into account. Point being, there is still a lot of uncertainty about how strong breezes will get through the start of the week. Based on the most recent statistical guidance, we have opted to extend the Gale Watch to all the marine zones.

Peak winds will begin to slacken during the middle of the week. The cutoff low near the Bahamas is expected to fill in over the next few days. The gradient flow will be able to break down and breezy conditions are expected to drop out of the forecast by Thursday to Friday. Synoptically, the broad upper level ridging across the eastern United States is on track to remain in place. Resulting stagnant flow without a nearby trough means that, for the Florida Keys, breezes are likely to slacken to light to gentle. Statistical guidance also suggests shower coverage will return to near normal values for this time of year, near 20 percent, later in the week. However, please keep in mind that this forecast depends on what happens with the breezy to windy conditions early this week, and there is not too much confidence in the extended forecast.

MARINE

Issued at 355 PM EDT Sun Oct 25 2026 A Small Craft Advisory is in effect for all the Florida Keys marine zones, and a Gale Watch will be in effect for all the surrounding waters for early Monday morning through early Tuesday morning. Frequent gusts to near 35 knots outside of shower activity are possible from early Monday to early Tuesday morning.

From synopsis: Building high pressure over the eastern United States and a persistent low northeast of the Bahamas will be able to sustain fresh to strong breezes overnight. Near gale wind gusts are possible for all the Florida Keys waters tonight through Tuesday. In addition, pulses of low level moisture will support elevated shower chances. Gale force wind gusts are possible near even shallow showers. Wave heights will stay elevated through mid week, even after breezes begin to slacken midweek.

AVIATION

(18Z TAFS) Issued at 355 PM EDT Sun Oct 25 2026 VFR conditions will persist at EYW and MTH. Short lived, fast moving SHRA will wax and wane near the terminals through the period. MVFR CIGs are possible near showers, and gusts up to 33 knots are possible. Cloud cover outside of showers will gradually increase during the evening, but persistent MVFR CIGs are not expected.

CLIMATE

On this day in 1903, the daily record cold high temperature of 70F was recorded in Key West. This also tied for the coldest high temperature ever recorded in October. Temperature records for Key West date back to 1872.

PRELIMINARY POINT TEMPS/POPS

Key West 75 84 75 84 / 40 30 20 30 Marathon 75 84 75 84 / 40 30 20 30

KEY WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Warning until 5 AM EDT Monday for FLZ076.

Coastal Flood Advisory until 5 AM EDT Monday for FLZ077-078.

GM...Small Craft Advisory until 5 AM EDT Monday for GMZ031>035- 042>044-052>055-072>075.

Gale Watch from late tonight through late Monday night for GMZ031>035-042>044-052>055-072>075.