Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
857 FXUS62 KKEY 180817 AFDKEY Area Forecast Discussion National Weather Service Key West FL 417 AM EDT Sat Oct 18 2025 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... -Bouts of breezy conditions will persist, lasting through the early part of the weekend. -Shower chances will increase on Sunday as winds veer to the south. -A Small Craft Advisory is in effect for all Keys marine zones. -A Coastal Flood Statement is in effect for all of the Florida Keys island communities. && .DISCUSSION... Issued at 416 AM EDT Sat Oct 18 2025 Dry, subsident air lingers over the Florida Keys early this morning. KBYX radar returns identified showers over the Florida Straits with few meteorological echoes near the island chain. Nighttime microphysics scans from GOES East show stratocumulus clouds across the Florida Straits. Along the island chain, dew points were able to drop into the upper 60s in the early morning hours. Winds along the reef continue to measure right around 20 knots with frequent gusts. Breezy conditions along the island chain are expected to linger through the day. .FORECAST... A high pressure system over the southeastern CONUS is responsible for the ongoing breezy conditions. Tonight, a low pressure system developing over the Great Lakes will push the high into the western Atlantic. Veering low to mid level winds will direct a plume of tropical moisture back across the Keys starting tonight along a weak warm frontal boundary. Additional moisture, veering winds, and divergence in the upper atmosphere will combine to create a more favorable environment for showers and thunderstorms during the second half of the weekend. Statistical guidance suggests shower coverage could increase to numerous across portions of the coastal waters. There is a good chance anyone spending a prolonged period of time outdoors on Sunday and Monday will get rained on, so plan accordingly! Shower chances will remain above average through Tuesday while a cold frontal boundary progresses into the northern Gulf. Breezes are expected to slacken mid week. Less wind convergence means shower chances will drop by Wednesday, though low to mid level tropical moisture will remain over the CWA. Eventually, the moisture will be pushed back south as another high pressure system builds over the eastern CONUS. Breezy conditions are once again possible at the end of next week. Weather conditions are subject to change, and exactly how strong breezes become will depend on how this late high pressure system develops. && .MARINE... Issued at 416 AM EDT Sat Oct 18 2025 A Small Craft Advisory is in effect for all nearshore and offshore waters of the Florida Keys. From synopsis, high pressure over the southeastern CONUS is responsible for Small Craft Advisory conditions across the Florida Keys today. The high will shift east into the Atlantic and allow a weak warm frontal pattern to lift north across the Keys coastal waters. Shower and thunder chances will be elevated from Sunday to Monday. Drier air will push over the Keys by mid week while a low pressure system over the eastern CONUS. Gentle to moderate breezes will start to freshen mid week as another high builds over the eastern CONUS. && .AVIATION... (06Z TAFS) Issued at 416 AM EDT Sat Oct 18 2025 && .CLIMATE... && .PRELIMINARY POINT TEMPS/POPS... Key West 85 76 87 77 / 20 30 40 40 Marathon 84 77 85 77 / 10 30 40 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Small Craft Advisory for GMZ031>035-042>044-052>055-072>075. && $$ 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