Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
274 FXUS62 KKEY 040823 AFDKEY Area Forecast Discussion National Weather Service Key West FL 423 AM EDT Thu Sep 4 2025 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 423 AM EDT Thu Sep 4 2025 Convection is getting an early start around the Florida Keys this morning. After yesterday`s rounds of widespread showers and scattered thunderstorms, a lull settled around the island chain for a few hours. This quiet did not last long however, as a line of showers with a few embedded thunderstorms recently developed across the Middle Keys and extended up towards the west coast of South Florida. This activity has since drifted into the eastern Straits with KAMX radar detecting a few more pulsing showers spawning over the Deep Gulf waters and the Lower and Middle Keys. Moderate southwest breezes are observed along the Reef stations west of ongoing convection with light to gentle breezes still experienced near the Upper Keys. Temperatures are the only values similar to yesterday around this time and are reporting in the lower 80s across the Keys. Little change with our synoptic players will result in another wet forecast for the Florida Keys in the short term. A stationary front is still parked over South Florida and the Keys with its associated surface trough stretched from the Gulf out north of the Bahamas and west of Bermuda. This trough continues to promote gentle to moderate westerly breezes across our waters while the stalled front acts as a local lifting mechanism for developing convection. Meanwhile, deep layer troughing remains over eastern CONUS and looks like its here to stay for at least the next few days. Yesterday evening`s KKEY 00z sounding shows a very moist tropical profile with a roughly unidirectional vertical wind profile from the west. Upstream of our area, CIMSS MIMIC PW notes a plethora of moist air primed to continue advecting over the Keys. Thus we once again find ourselves with plenty of moisture, lift, and eventually instability as the atmosphere recovers and daytime heat is reintroduced into the environment. Opted to return to 80% PoPs with chance thunder during the day as a result, but will also aim for 60% tonight as convection over the last few days has had somewhat of a diurnal signal with its lulls. The Weather Prediction Center has once again given the Florida Keys a Marginal Risk (level 1 of 4) for excessive rainfall today. Any thunderstorms that track over the Keys will be capable of producing heavy rainfall. It still looks like we`ll break free of this pattern starting Saturday as the mid to upper level troughing and the surface low exit to the northeast. This will allow weak ridging to slide back into the area with winds gradually flipping back around to a closer to normal southeasterly wind direction. While the big players for heavy rainfall will be out of the picture, another undulation of moisture looks to settle in from the east keeping rain chances just above normal into next week. && .MARINE... Issued at 423 AM EDT Thu Sep 4 2025 No watches, warnings, or advisories are currently in effect for the coastal waters of the Florida Keys. From synopsis, a broad surface low along a stationary front stretching from the Gulf eastward to the Florida Peninsula will maintain westerly winds across the Florida Keys marine zones today. The front will remain rooted in place through the next few days, while the low meanders northeast into the western North Atlantic, promoting southwest to west breezes throughout the week. Abundant moisture will promote well above normal rain and thunder chances through the end of the work week. High pressure slowly building across the North Atlantic over the weekend will support reduced rain and thunder chances, although remaining at or above normal. && .AVIATION... (00Z TAFS) Issued at 423 AM EDT Thu Sep 4 2025 The long running wet weather pattern will continue for yet another day across the Keys. As a result, periodic rounds of sub VFR conditions and gusty winds are expected with a chance for thunderstorms. Aside from convective disturbances, surface winds will generally be gentle out of the west. && .PRELIMINARY POINT TEMPS/POPS... Key West 90 79 91 80 / 80 60 80 50 Marathon 89 79 89 80 / 80 60 80 50 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...JAM Aviation/Nowcasts....11 Data Acquisition.....JAM Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest