


Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
110 FXUS62 KKEY 170820 AFDKEY Area Forecast Discussion National Weather Service Key West FL 420 AM EDT Fri Oct 17 2025 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... -Low level moisture returns briefly today with slightly higher rain chances. -Bouts of breezy conditions will commence today, lasting through the early part of the weekend. Small Craft Exercise Caution headlines are necessary for the Florida Keys coastal waters. -A Small Craft Advisory may be required for portions of the weekend. -A Coastal Flood Statement is in effect for all of the Florida Keys island communities. && .DISCUSSION... Issued at 423 AM EDT Fri Oct 17 2025 Thick low altitude cloud cover and clusters of showers across the Florida Keys coastal waters indicate the atmosphere is slightly more active than yesterday. GOES East satellite observations show stratocumulus lingering over the Straits and the Outer Gulf. However, despite the low level moisture, CIMSS Precipitable Water scans measured an environmental PWAT around 1 inch. Deep layers of sinking air remain over South Florida, as was seen in the 00Z KKEY sounding. This subsidence is expected to remain for the rest of the day. The most notable change across the Keys today will be the winds. A high pressure system over the eastern CONUS is sinking south towards the Florida peninsula and tightening the pressure gradient. Breezes along the reef were gentle to moderate after midnight, though Carysfort Reef measured moderate to fresh breezes before sunrise. This is consistent with an expected wind surge, forecast to arrive in the Keys later today. Small Craft Advisories may be required tonight. .FORECAST... After the wind surge moves across the Florida Keys, the environment will be dry for the first half of the weekend. However, Sunday and Monday are more complicated. The aforementioned high pressure system will move into the Atlantic ocean and cause winds to veer across the Keys. More tropical moisture will be directed towards the island chain in concert with the veering winds to mark the start of the work week. Due to increased CAPE and additional low level moisture, opted to put a slight chance of thunderstorms back into the forecast for Sunday and Monday. Details on where showers will form is not certain at this time, and statistical guidance shows a range of 30 to 60 percent PoPs on Sunday night. Rainy season has not left yet, though bouts of widespread shower coverage will become less frequent towards the end of the month. && .MARINE... Issued at 423 AM EDT Fri Oct 17 2025 Small Craft Should Exercise Caution for all waters of the Florida Keys today except for Florida Bay, where Small Craft Should Exercise Caution for increasing winds. A Small Craft Advisory may be required for all waters of the Florida Keys. From synopsis, a high pressure system moving towards the southeastern CONUS form the Great Lakes will support breezes freshening to moderate to fresh today and tonight. Small Craft Advisories may be required as breezes are expected to be just below the threshold. Shower coverage will rise today as the wind surge moves south across the Florida Keys coastal waters. Environmental conditions will become more supportive of showers and thunderstorms on Sunday and Monday. && .AVIATION... (06Z TAFS) Issued at 423 AM EDT Fri Oct 17 2025 VFR conditions are expected to prevail today. With that said, there will be a chance for brief sub VFR conditions due to expected passing scattered showers. Winds will be gentle to moderate out of the northeast, freshening through the day. && .CLIMATE... In 1910, a category 3-4 Hurricane moved north northeast passing about 25 miles west of Key West. A navy tug at the Dry Tortugas reported a minimum pressure of 28.26" (957 mb) with calm lasting 40 minutes in the eye. At Sand Key the minimum pressure was 28.40" (962 mb) with wind estimated at 125 mph. In Key West, the minimum pressure was 28.50" (965 mb) with wind gusts to 110 mb and a storm tide of 15 feet and large swells to 15 feet along the western shores. Tropical Storm winds lasted more than 30 hours. && .PRELIMINARY POINT TEMPS/POPS... Key West 85 76 86 77 / 30 20 10 30 Marathon 84 76 84 77 / 30 10 10 20 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...AJP Aviation/Nowcasts....11 Data Acquisition.....11 Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest