textproduct: Key West

KEY MESSAGES

- Overnight showers and thunderstorms, some strong, will taper by early Tuesday morning.

- A more active weather pattern will develop with higher chances for showers and thunderstorms starting Tuesday night.

- Highest rain chances are expected to occur late Tuesday into Wednesday with a brief lull, followed by another round of higher chances for the end of the week.

DISCUSSION

Issued at 1117 PM EDT Mon Aug 3 2026 It has been a busy evening across the Florida Keys! Earlier in late afternoon, around 3:30 PM, a cloudline developed adjacent to the Middle Keys, producing a waterspout at one point while also bringing spotty bouts of moderate rainfall to the Middle Keys. AS this cloudline collapsed and dispersed an outflow boundary, there was also an outflow boundary approaching from the southern portions of the peninsula. If that wasn't enough, there was also another outflow boundary approaching from convection offshore of Cuba. It was passed along to the evening team that our atmosphere was primed for some hefty activity, and once these three boundaries collided, it was off to the races. Multiple pockets of strong thunderstorms near the Lower and Middle Keys brushed past some of our marine platforms, and wind gusts of 35 to 39 knots, or 40 to 45 mph, were reported throughout the evening. MRMS radar- derived rainfall amounts reflect 6-hour rainfall totals across the Middle and Upper Keys anywhere from zero to just a few hundredths. Meanwhile, across the Lower Keys, rainfall amounts of approximately half of an inch to one and a half inches were detected. There are some pixels of nearly 2 inches in the vicinity of Big Pine Key, but our highest totals remained to the south and west of Key West where heavy showers appeared to be nearly stationary due to the lack of a meaningful steering flow.

As of now, the last of the strongest thunderstorms appear to have tapered off based on our KBYX radar trends. Overlaying our neighboring KAMX radar in Miami helps us identify particularly stronger towering thunderstorms, and reflectivity values have gradually come down at the higher tilts. It appears that the impressive and electric activity is succumbing to the environment as it has become "worked over". The current widespread showers and thunderstorms should continue to diminish into the overnight hours, and better weather conditions should return. No changes are proposed to the current package as this evening update is being issued unusually later than normal.

MARINE

Issued at 1117 PM EDT Mon Aug 3 2026 Widespread showers with embedded, strong thunderstorms will continue to percolate initially across the marine zones, but will taper off in the hours before sunrise. DUring the day on Tuesday, conditions should be widely improved, but rain and thunderstorms chances see an uptick Tuesday night once again. This will lead to another round of unsettled weather conditions featuring periods of stronger winds and rougher seas/nearshore waters.

AVIATION

(00Z TAFS) Issued at 1117 PM EDT Mon Aug 3 2026 Nearby showers and thunderstorms will continue to bring intermittent MVFR CIGs to either island terminal, but the best chances will be at EYW at the beginning of the 00Z TAF period. The strongest thunderstorms will be capable of IFR CIGs and VIS with gusty variable surface winds, but this activity should temporarily diminish by 06Z. Thereafter, VFR conditions should prevail with only some light, spotty showers and southeasterly winds near 5 knots becoming variable again near the end of the TAF period.

PRELIMINARY POINT TEMPS/POPS

Key West 82 92 82 92 / 30 20 40 60 Marathon 82 91 82 90 / 30 20 40 60

KEY WATCHES/WARNINGS/ADVISORIES

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