textproduct: Key West

KEY MESSAGES

- Gentle to moderate easterly to southeasterlies this morning will gradually slacken to a light breeze through mid to late week.

- A Saharan Air Layer (SAL) will remain over the region for the next several days, keeping slim to no Shower and thunder chances for much of the week.

- Near to slightly above normal temperatures will continue for much of the week with not much relief overnight. Remember to stay hydrated and take breaks.

DISCUSSION

Issued at 400 AM EDT Tue Aug 11 2026

A deep layered ridging stretches east/west across northern and central Florida. This is resulting in gentle to moderate easterlies across the Keys and surrounding waters. There is some indication that the northwestern reaches of a broad Saharan Air Layer has spread across our area. This past evenings sounding indicated considerable CAPE. However, precipitable water was 1.53 inches, very near the 10th percentile for the day. In addition, there was a robust nose of inhibition based around 850 mb. As a result, there have only been a few showers present across our area through the evening. Temperatures are drifting slowly downwards through the mid 80s with dew points ranging in the mid to upper 70s.

Through mid week a low amplitude mid latitude trough will amplify slightly over the eastern United States. In response, the deep layered ridge will weaken as it gradually shifts southward across Central Florida. Expect surface winds to trend downwards through this stretch, potentially becoming light and variable after mid week as the surface ridge becomes split daily by mainland day time heating. No significant trend in temperatures are expected. Highs will remain near 90 and lows in the lower to mid 80s. Dew points will remain in the mid to upper 70s.

Heading into late week, a shortwave trough will help to amplify the eastern United States mid latitude trough a bit more, further weakening the nearby ridging. Meanwhile, all guidance points to a broad lower level trough advancing westward across our area in the early Friday through Saturday time frame. As the trough draws near on Friday, winds may strengthen moderately out of the northeast to east, then shift east to southeast heading into the weekend as the trough moves through and west of our area. In addition, this trough will bring increased confluence, less inhibition, and much higher precipitable water at near 2 inches. For this reason a period or two of at low to mid chance for showers and thunderstorms appear reasonable for this time frame.

MARINE

Issued at 400 AM EDT Tue Aug 11 2026

A surface ridge across Central Florida will shift southward into South Florida over the next couple of days. As a result, gentle to moderate easterly breezes will relax to a light to gentle breeze. Some variability is expected to build in after mid week as the ridge weakens and is fractured daily by daytime heating. Late in the week, breezes will begin strengthening out of the northeast as the ridge lifts back into Central and a broad lower level trough begins advancing westward across our area. This weekend winds will shift east to southeasterly, becoming gentle to moderate with near or slightly above normal rain chances as the trough moves through the Keys area.

AVIATION

(00Z TAFS) Issued at 400 AM EDT Tue Aug 11 2026

VFR conditions will prevail at the island terminals today. Surface winds will be light to gentle easterlies.

PRELIMINARY POINT TEMPS/POPS

Key West 92 85 92 85 / 10 10 10 10 Marathon 91 84 92 84 / 10 10 10 10

KEY WATCHES/WARNINGS/ADVISORIES

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