FXUS62 KKEY 190912 AFDKEY Area Forecast Discussion National Weather Service Key West FL 512 AM EDT Tue Aug 19 2025 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 339 AM EDT Tue Aug 19 2025 The overnight shift started off with a little bit of activity on our KBYX radar as some residual showers and thunderstorms from earlier in the evening were pushing southwestward across our area. These continued to diminish into the middle of the night, but we are currently seeing a small resurgence in activity across the forecast area. This just means that we may be set up for a beautiful sunrise this morning, with a few island communities possibly seeing some light showers when its time to head to work or school. Overall breezes are still light to gentle out of the north, but any collapsing showers or thunderstorms will result in some variability. The forecast over the next few days is a little messy to sort out, courtesy of Major Hurricane Erin. As of 5 AM EDT, Erin was located roughly 630 miles to the ENE of Key West. The system looks pretty large on satellite, and we can see some of the higher cirrus clouds across our forecast area are from the "exhaust" of Erin. The current forecast has the system turning to the north today. As Erin passes well to our east, moisture will advect from the north and showers and thunderstorms could be more efficient at producing heavier showers. With the fairly slow movement the system has, moisture will be able to sort of "build up" in the vertical profile, and it is possible that the 30 percent chance of rainfall we have advertised, specifically for Wednesday, may be a little too low. Regardless, the next couple of days have the opportunity to be a little wetter and a little cloudier than we think right now, it just depends on Erin's motion. Once Erin pushes far enough northward, possibly from Thursday afternoon and onward, ridging will be able to build back in. Guidance is suggesting substantially dry air above 850mb, so our moisture source for any activity will be very shallow. Even though showers will still be possible, since it is August in Florida, a shallow moisture source means they will likely be short lived and unable to build into thunderstorms. The bottom line is that weather conditions should feel more normal once Erin pushes away, but you may want to keep an umbrella close until then. && .MARINE... Issued at 339 AM EDT Tue Aug 19 2025 There are no watches, warnings, or advisories in effect for the Florida Keys local waters. From synopsis, Major Hurricane Erin will turn due northward over the open Atlantic over the course of today. The increasingly expansive circulation of Erin will result in a transition from light to gentle northerly breezes across Florida Keys coastal waters overnight, to gentle to moderate northwest breezes Tuesday and moderate to fresh westerly breezes on Wednesday. A slight swell from the north will lead to elevated seas in northern portions of the Florida Straits. As Hurricane Erin migrates farther away toward the north and northeast, a weak subtropical high pressure ridge will settle over Florida Keys coastal waters, resulting in a lighter wind pattern Thursday through Saturday. && .AVIATION... (06Z TAFS) Issued at 339 AM EDT Tue Aug 19 2025 VFR conditions will prevail at both island terminals through the TAF period. A similar regime to what occurred yesterday may occur today. Convection is anticipated to flare over the mainland and then potentially move south to southwestward off the mainland. As a result, we cannot rule out a shower or thunderstorm to either terminal late in the day to the evening hours. Due to the uncertainty and low to average confidence, VCSH was left out of the TAF for now. Near surface winds will remain northerly this morning between3 to 8 knots before becoming more northwesterly for the afternoon and evening. && .CLIMATE... On this day in Keys weather history, in 2022, the daily record warm low temperature of 84F was last recorded in Key West. Temperature records for Key West date back to 1872. Also, in 2024, the daily record warm low temperature of 84F was last recorded in Marathon. Temperature records for Marathon date back to 1950. && .PRELIMINARY POINT TEMPS/POPS... Key West 93 83 93 82 / 30 30 30 30 Marathon 91 82 91 83 / 30 30 30 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...DP Aviation/Nowcasts....MJV Data Acquisition.....MJV Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest