textproduct: Key West

KEY MESSAGES

- Conditions are shaping up to be favorable for island cloud line development as well as waterspout formation late this afternoon, particularly near the Lower Keys.

- A typical summertime pattern will continue tonight, with near or slightly below normal rain chances and warm and muggy conditions continuing.

- A weak Saharan Air Layer is on track to move over the Florida Keys by mid week and diminish shower chances for a day or two. Heat indices may creep towards 110 around mid week.

MARINE

Issued at 240 PM EDT Tue Jul 7 2026 Showers have been surprisingly inactive across the Florida Keys today. Winds backed easterly in the early afternoon ahead of thunderstorms developing over Cuba. Robust outflow boundaries have not formed as of 2 PM, and breezes along the reef are light to gentle. Waterspouts are still the primary hazard of concern for the remaining afternoon, and cloud lines can form very rapidly in July.

From synopsis, breezes across the Florida Keys coastal waters are expected to shift between easterly and southeasterly and trend upwards from light to gentle to gentle to moderate beginning tonight as the western edge of the Atlantic ridge strengthens and lifts northward into Central Florida. Winds will tend to peak in the evening where periodic cautions may be required for portions of Keys waters. Advisories cannot be completely ruled out at this time. Shower coverage will wax and wane between slight and a chance, with a day or two drier stretch arriving mid week.

AVIATION

(18Z TAFS) Issued at 240 PM EDT Tue Jul 7 2026 VFR conditions prevail at EYW and MTH for the upcoming TAF period. Cloud line showers are a concern for the rest of the afternoon, thus VCSH was added to both sites. Cloud lines are expected to wane after sunset along with a slight drop in wind speed. A Saharan Air Layer will begin to move into the Keys tomorrow, so expect a decrease in cloud cover after sunrise. Short lived MVFR to IFR CIGs are possible near showers.

PREV DISCUSSION

Issued at 400 AM EDT Tue Jul 7 2026 The western flank of the Atlantic ridge will begin strengthening today as it steadily lifts northward into Central Florida. As a result, winds will steadily firm up out of the east to southeast. This change is expected to contribute to an environment conducive for waterspout formation along an island cloud line this afternoon, especially in the Lower Keys. Expect continued seasonable warm and humid conditions.

Winds will freshen further tonight as the ridge strengthens and becomes positioned further north. For the next few days, east to southeasterly breezes will tend to peak in the evening and lull during the day. Spells of breezy conditions are likely. Drier and more stable air is expected to move in and by Wednesday, rain chances are expected to slip to dimes or less, lasting a day or two. Expect continued slightly above normal temperatures with the increased flow doing an even better job at holding temperatures up in the mid 80s. Dew points will remain in the mid to upper 70s.

Heading into late week, guidance is pointing towards a cut off upper low working its way westward across the central Bahamas and weaken as it shifts into Cuba and Florida Straits. An associated lower level inverted trough will push westward across our region in this time frame. This may bring with it increasing instability and low level moisture. As a result, rain chances should jump up, becoming at least a mid to high chance. This is not yet fully reflected in the current forecast. Much drier lower levels will be hot on its heels and the later portion of the weekend and rain chances should drop back to dimes or less.

KEY WATCHES/WARNINGS/ADVISORIES

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