textproduct: Key West

KEY MESSAGES

- A wetter pattern is in place and chances for rain and thunder will remain elevated through at least the next couple of days. - Breezy to windy conditions will gradually develop through this afternoon following the cold front passage, and are expected to continue through most of the week.

- We should see improving drought conditions due to beneficial rains this week.

DISCUSSION

Issued at 415 AM EDT Tue Mar 17 2026

What a stormy and wet overnight for the Florida Keys! As a cold front slowly lurch towards the Florida Keys, ample moisture and instability out ahead of the front came to life. Coverage quickly increased and all of the Florida Keys saw multiple rounds of showers and thunderstorms. All island communities picked up at least 0.50 inch but there were certainly areas that received well over that amount. In fact, The Florida Keys Marathon Airport set a new daily record for yesterday, March 16th with 2.14", shattering the previous record of 0.34"!

Rain remains ongoing this morning, though it has transitioned to more of a stratiform rain with embedded convection. The stronger activity and thunderstorms have settled across the Straits of Florida and will persist this morning. The cold front itself has yet to pass over the Keys. In fact, it is just beginning to enter the extreme Southeast Gulf waters. Behind this front we will see freshening northerly breezes with breezy conditions expected for the island chain towards the afternoon.

As the front steadily moves in, it will undercut the mid level flow and gradually decrease rain chances from west to east. That being said, the front will stall across the Straits of Florida over the coming days. This will allow for moisture to continue to pool across the area. Despite a high pressure moving in across the region, the front may still have enough dynamics with it to allow for a couple more days of wet weather. This would not be a bad thing as we have been dealing with moderate drought conditions and this is surely helping things.

We will also see a prolonged period of breezy to at times, windy conditions over the next few days. The strong high that fill in behind the front will keep a tight pressure gradient across the Southeastern U.S. This feature will slowly settle in the Southeast U.S./Southwestern Atlantic by the end of the week, allowing for breezes to relax.

MARINE

Issued at 415 AM EDT Tue Mar 17 2026

Widespread rain with embedded showers and thunderstorms will persist this morning and gradually diminish in coverage through the afternoon. The stronger elements will be found across the Straits of Florida where mariners should expect bouts of frequent lightning, gusty erratic winds, and blinding downpours. Meanwhile, a cold front is steadily marching south and has entered the extreme Southeast Gulf waters. Expect freshening northerly breezes this morning with building seas. Small Craft Advisory conditions will develop this morning and gradually overspread to the remaining waters throughout the day. Thereafter, high pressure filling in behind this front will maintain a prolonged period of fresh to occasionally strong breezes. There will be very brief lulls at times where breezes could slacken to gentle to moderate. Breezes are not expected to appreciably slacken until closer to Friday when the high weakens and settles closer to the Florida Peninsula.

AVIATION

(06Z TAFS) Issued at 415 AM EDT Tue Mar 17 2026

Outside of any heavier showers or thunderstorms, we are expecting episodic MVFR conditions. Shower coverage will gradually wane from west to east through the morning and into the afternoon. A cold front is approaching from the north and expecting northerly winds to increase in its wake. Expecting a crosswind magnitude of 20 to 25 knots to develop by the afternoon for both terminals. Pilots should be advised that while surface winds will be northerly, beginning around 2000 feet, winds will quickly shift and come from the southwest.

PRELIMINARY POINT TEMPS/POPS

Key West 75 64 75 67 / 40 30 40 50 Marathon 76 64 75 67 / 50 40 50 50

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...Small Craft Advisory GMZ033-034-055-075.