textproduct: Key West

KEY MESSAGES

- A Saharan Air Layer is moving across the Florida Keys. The SAL is on track to lift out of the Keys by the weekend.

- Heat will be the primary weather concern this week. Heat indices may creep towards 110 before the weekend.

- Shower coverage is expected to increase at the end of the week while a low in the upper atmosphere tracks westward across the Keys.

DISCUSSION

Issued at 1030 PM EDT Wed Jul 8 2026 Generally unremarkable weather has continued across the Florida Keys this evening courtesy of ridging draped over the region. Current observations along the island chain show temperatures still in the mid 80s with head indices anywhere from the mid 90s to near 100F. The silver lining, for what it's worth, is that the breeze outside is keeping things from feeling too stuffy. The ASOS at Key West International Airport has reported sustained winds near 15 mph with frequent gusts near 20 mph. Farther up the island chain, Marathon is also showing sustained winds near 15 mph, but gusts have been less frequent. Overall, a little warm, but this would feel a lot worse if the air wasn't moving like this.

GOES-19 Dust indicates there is some Saharan Air Layer (SAL) across the area, and this explains the lack of shower activity on our KBYX radar. Typically, the upper air sounding would also show SAL in the area with a layer of dry air in the mid layers, but our 00Z KKEY sounding from this evening sampled notable dry air from around 900mb up to 600mb. The SAL is in there somewhere, but there is also some regular dry air too. All of this is to say the inherited nonexistent pops seem appropriate for the short term forecast. Radiational cooling is unlikely due to the elevated winds, and the field of fair weather cloud cover noted on GOES-19 Nighttime Microphysics should remain through the overnight hours. Therefore, the advertised overnight lows in the mid 80s are on track to verify.

No changes are proposed to the current forecast package.

MARINE

Issued at 1030 PM EDT Wed Jul 8 2026 Small Craft Should Exercise Caution across all Florida Keys local waters, excluding Florida Bay, due to fresh east to southeast breezes. Moderate to fresh east to southeast breezes will hold steady over the next few days as an Atlantic ridge draped across Central Florida strengthens. Winds will tend to peak in the evenings and lull slightly during the day. Breezes are expected to ease back gradually through the weekend. Shower and thunder chances will be slight or less over the next few days, but trend sharply upwards late in the week as a weak low level trough pushes westward across our area.

AVIATION

(00Z TAFS) Issued at 1030 PM EDT Wed Jul 8 2026 Clouds based between FL025 and 035 will lead to occasional MVFR CIGs at both terminals, especially EYW, throughout the first half of the TAF period. However, the fair weather cloud field responsible for this is moving swiftly, and any MVFR observations should be short lived, minimizing any impacts. Sustained surface winds of near 15 knots will prevail out of the east to southeast, so crosswind concerns are virtually nonexistent. Weather will remain dry onsite.

PRELIMINARY POINT TEMPS/POPS

Key West 84 91 83 91 / 10 0 20 30 Marathon 84 90 83 90 / 0 0 30 30

KEY WATCHES/WARNINGS/ADVISORIES

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