textproduct: Key West

KEY MESSAGES

- A swath of Saharan dust will remain across the Keys this afternoon and evening, maintaining rain-free conditions.

- Rain chances will slowly increase later this week as dust concentrations decrease.

- Warm and muggy conditions will continue throughout the work week, with light and often variable breezes.

DISCUSSION

Issued at 1146 AM EDT Wed Aug 19 2026 The 12z morning sounding at KEY sampled a continued very dry troposphere, consistent with a stagnant wave of low- and mid-level Saharan dust over the Florida Keys, as well as an expansive ridge bridging across the entire southern half of the CONUS. The sounding sampled a total precipitable water value of 0.99", a record for the date, and more characteristic of February or March than late August. GOES-19 visible satellite imagery is detecting mostly clear skies across the Keys and the adjacent nearshore and offshore marine zones.

Ample solar radiation will allow temperatures to easily climb at or just above 90F again today. With similar sunny skies across the South Florida Mainland, an in situ mesoscale low will form, supporting freshening southwesterlies across the Upper Keys and the adjacent nearshore waters. Outside of minor brief upticks to the wind speeds in these areas, no changes proposed to the inherited short- term forecast.

MARINE

Issued at 1146 AM EDT Wed Aug 19 2026 A ridge axis draped across the Florida Keys will maintain a mostly variable wind pattern through the remainder of the week with wind speeds mainly less than 10 knots. However, brief surges in wind speeds are possible in the evening hours with breezes occasionally approaching 15 to 20 knots near the Upper Keys. Exercise cautionary conditions may be periodically required for waters adjacent to the Upper Keys. A broad swath of Saharan air blanketing the area will maintain rain-free conditions today, but rain chances will slowly increase into late week as moisture slowly recovers. By the weekend, a light and variable flow pattern should persist on Saturday before winds gradually increase and become more southeasterly by late weekend and into next week.

AVIATION

(15Z TAFS) Issued at 1146 AM EDT Wed Aug 19 2026 VFR conditions will prevail at both island terminals through 12z Thursday morning. Near-surface winds out of the northwest to north will become variable at times, especially for MTH.

PRELIMINARY POINT TEMPS/POPS

Key West 92 83 92 82 / 0 10 0 10 Marathon 91 83 90 83 / 0 20 0 10

KEY WATCHES/WARNINGS/ADVISORIES

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