textproduct: Key West

KEY MESSAGES

- Light to gentle southeast to southerly breezes will gradually slacken and back east to southeasterly tonight.

- A typical summertime pattern will continue through around mid week. Rain chances will remain near or slightly below seasonable levels (10-20%), with the warm and muggy conditions continuing.

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

MARINE

Issued at 215 PM EDT Mon Jul 6 2026 Southerly breezes diverted showers and isolated thunderstorms towards the northern waters of the Florida Keys. By noon, showers over the northern waters have mostly dissipated. Thunderstorms have been able to reform west of the Dry Tortugas, but otherwise shower and cloud cover has been rather sparse across the Florida Keys waters. Breezes are still expected to back slightly southeasterly tonight, and a chance remains that cloud lines could form off the Lower and Middle Keys. Tonight, showers may be able to form as breezes freshen slightly across the southern waters. Thunderstorms moving off of Southern Florida will also be a concern.

From synopsis, light to gentle breezes will persist across the Florida Keys coastal waters tonight and tomorrow. Breezes are expected to shift between easterly and southerly and trend upwards beginning late Tuesday as the western edge of the Atlantic high 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 are not anticipated 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 215 PM EDT Mon Jul 6 2026 VFR conditions prevail at both EYW and MTH for the upcoming TAF period. Near surface winds are on track to slowly back southeasterly before sunset, and a nocturnal surge in wind speed towards near 10 knots is expected. Cloud line showers capable of MVFR to IFR VIS and CIGs may be able to develop late in the afternoon after the wind shift.

PREV DISCUSSION

Issued at 400 AM EDT Mon Jul 6 2026 Weak surface through lower level Atlantic ridging will remain across South Florida for the next few days. This will keep breezes light to gentle and broadly out of the southeast. Mesoscale effects will result in winds tending to strengthen slightly during the overnight hours. This flow will ensure slightly above normal temperatures with highs near 90. Dew points will remain in the mid to upper 70s with overnight lows struggling to fall out of the mid 80s and near record warm lows. Weak anticyclonic flow aloft and weak predominantly mesoscale/diurnal forcing below will result in seasonable shower and thunderstorm potential through this period with island driven convection usually ending up on our nearshore gulf side waters.

Deep layered troughing over the eastern United States will begin lifting out on Tuesday. This will allow the western flank of the surface through lower level Atlantic ridge to strengthen slightly while it lifts northward into Central Florida. As a result, surface winds are expected to trend upwards, with peaks in the evening and lulls during the day. This will help to keep highs near 90 but also hold up overnight lows in the mid 80s. Rain and thunder chances may dip slightly as a swath of drier and more stable air moves across the Keys for a fairly short period in the late Wednesday through late Thursday time frame.

Through the latter part of the week, upper level ridging will give way to a weakening cut off upper low retrograding across Cuba. Associated weak lower level troughing is expected to carry westward across our area and be accompanied by a swath of increased lower level moisture. As a result, rain chances may tick up a notch or two towards the end of the work week. Some, not all, statistical guidance is beginning to pick up on this. Expect continued slightly warmer than normal conditions with dew points remaining in the mid to upper 70s.

PRELIMINARY POINT TEMPS/POPS

Key West 84 91 84 92 / 10 10 10 10 Marathon 83 92 84 93 / 10 20 20 10

KEY WATCHES/WARNINGS/ADVISORIES

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