textproduct: Key West

KEY MESSAGES

- Gentle to occasional moderate northeast to east breezes will gradually slackening over the weekend. - Little to no measurable rain will maintain continued moderate drought conditions in the Florida Keys through the weekend, and into the beginning of next week.

- Temperatures will remain near to slightly above normal, with highs in the lower to mid 80s, and lows in the lower to mid 70s.

- A frontal boundary will move through the Keys sometime Monday/Monday evening, potentially bringing another period of windy conditions, lower humidity, and increasing rain chances.

DISCUSSION

Issued at 401 AM EDT Sat Apr 18 2026

Another rinse and repeat overnight for the Florida Keys. Limited moisture and large-scale subsidence is limiting shower coverage. Surface high pressure centered across the Atlantic and eastern Gulf Basin is maintaining generally easterly winds across our CWA. Temperatures are a little warmer this morning with mid to upper 70s, thanks to our winds going more easterly. Low level moisture has been slowly creeping upwards and our dew points this hour are near 70 degrees.

Through the next 24 to 48 hours, a surface high that sprawls across the Atlantic and Gulf Basins will slide further east and away from the Keys. This will lead to a col region developing across the Keys Sunday with a period of light and variable winds. Meanwhile, an upper level ridge centered over the Gulf will slowly slide east and become flattened in response to an upper level trough diving out of the Central Plains. Despite the gradual influx of moisture in the lowest levels, we will remain too suppressed and therefore will maintain rain chances at 10 percent or less.

By Monday, a strong surface high pressure will barrel out of the Central Plains and drive a back door front across the Keys Monday evening and overnight. In the wake of the front, we expect a sharp increase in winds with windy conditions developing Monday night. Thereafter, the surface high will slowly meander eastward and eventually settle across the Atlantic off the Southeast U.S. coast by Thursday. As a result, wind conditions will persist through Wednesday morning before easing to breezy conditions through the end of the week.

There still remains high uncertainty as to how much moisture will accompany the front and the subsequent position after it passes through. Previous runs of the GFS had the moisture plume stalling across the Keys through the first half of the week. More recent runs has the moisture settling to our south Tuesday into Wednesday and lifting back slowly northeastward as a pseudo warm front Wednesday night through the end of the week. The ECMWF has some similarities and some subtle differences. The ECMWF also shows the moisture plume pushing south of the Keys Tuesday, but stalls across the Greater Antilles and remains to our south. Therefore rain chances remain low and will depend on where that moisture lines up next week.

MARINE

Issued at 401 AM EDT Sat Apr 18 2026

Gentle to occasionally moderate easterly breezes this morning will slacken across most of the Florida Keys coastal waters with the exception of the Straits of Florida. This is due to a surface high across the Atlantic pulling further east away from the Florida Keys. By Sunday, expecting a col to develop with a period of light and variable breezes, especially across the Gulfside/Bayside waters. Breezes will gradually freshen Sunday night into Monday as a frontal boundary approaches from the north and northeast. This front is expected to bleed through Monday evening and overnight and a strong surface high is expected to push in behind. This will result in breezes sharply freshening overnight Monday. Confidence is high that fresh to strong breezes will develop overnight Monday and persist through Wednesday morning. Thereafter, the high will slowly meander into the Atlantic and allow breezes to gradually slacken through the end of the week.

AVIATION

(06Z TAFS) Issued at 401 AM EDT Sat Apr 18 2026

Brief periods of MVFR CIGs will be possible from passing strato- cu this morning. Otherwise, expecting VFR conditions with easterly winds slowly decreasing through the forecast period.

PRELIMINARY POINT TEMPS/POPS

Key West 84 75 84 74 / 10 10 10 10 Marathon 83 75 84 74 / 0 10 10 10

KEY WATCHES/WARNINGS/ADVISORIES

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