Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
791 FXUS62 KKEY 241923 AFDKEY Area Forecast Discussion National Weather Service Key West FL 323 PM EDT Mon Aug 24 2026 ...New DISCUSSION, MARINE, AVIATION, PREV DISCUSSION... .KEY MESSAGES... - Slight chance of showers and thunderstorms develop late tonight, with increasing shower and thunder chances through the week. - Highs near 90 and dewpoints in the mid to upper 70s suggest afternoon heat indices will peak at 105 to 108 degrees. && .MARINE... Issued at 323 PM EDT Mon Aug 24 2026 Generally gentle east to southeast breezes will prevail across the majority of the Florida Keys coastal waters. The exception at times will be the Southeast Gulf, where daytime heating across the mainland will lead to breezes decreasing briefly during the afternoons. Otherwise, expect breezes to peak overnight to gentle to moderate at times. As a ridge across the Atlantic slides westward, better moisture will pivot through, leading to a more active weather pattern through the later half of the week. && .AVIATION... (18Z TAFS) Issued at 323 PM EDT Mon Aug 24 2026 VFR conditions expected to prevail. Watching for showers and potential thunderstorms to develop late overnight but confidence is not high enough to put mentions in the current TAF at this time. && .PREV DISCUSSION... Issued at 439 AM EDT Mon Aug 24 2026 CIMSS products continue to show a mainly split ridge pattern in place across the area. One ridge remains centered over Texas, New Mexico, and Oklahoma while the other ridge is centered just to the southwest of the Azores. In between these ridges, a mean layer upper level trough remains anchored across the Great Lakes, Northeast U.S. and the Mid-Atlantic states. Florida remains in this sort of Goldilocks zone in between all the large synoptic scale features. However, at the surface, the ridge over the Atlantic has nudged a little further west. Marine observation platforms surrounding the Island Chain are recording southeast to south breezes near 5 knots as a result. GOES 19 Total Precipitable Water (TPW) products shows estimated PWATs of 1.5 to 1.7 inches in place across the Keys. KBYX radar has been detecting shower and thunderstorm activity throughout the overnight, though, this activity has been mostly confined to the SE Gulf waters and has recently waned. GOES 19 Nighttime Microphysics imagery shows mostly clear to partly cloudy skies across the Keys with mainly low level cumulus to stratocumulus, perhaps some cumulus congestus. Temperatures along the Island Chain are in the lower to mid 80s and dew points are in the mid 70s. The cool spot is once again the Big Pine Key RAWS where the temperature has dipped to 75 degrees so far overnight. .FORECAST... The western periphery of the ridge over the Atlantic will maintain modest control of the Keys for the next day or two. It will start to gain stronger influence across the area heading towards mid week. Therefore, expect another day of slight chance of showers and thunderstorms as well as tonight. Since the flow is still somewhat weak, the potential exists for another cloud line today. Other than that, some hi-res model guidance remains rather insistent on most of the convection developing just north of the Chain later this morning heading into the afternoon hours. Most guidance suggests the activity waning after that with not much anticipated for the late afternoon and evening hours. However, we still cannot rule out an isolated shower or thunderstorm during that time. As the ridge slowly builds into the Keys through the week, it will be met with increasing moisture. Therefore, increasing chances for showers and thunderstorms are expected as the week progresses. Latest indications are for this activity not to be all that rambunctious, but rather more of the garden variety type convection. Perhaps a storm or two becomes strong enough to warrant a Special Marine Warning, etc. The interesting time frame actually looks to be towards the latter half of the week. More in the way of upper level support is expected which would give any showers and storms more ferocity. Therefore, it is during this time frame when the more widespread warnings or statements might be needed as well as more widespread shower and storm activity. The aforementioned high pressure will continue to build across the region through the week and into the weekend. This will result in a more stout east to southeast flow with peaking breezes during the evening and overnight hours and lulling during the morning and afternoons. In addition, expect daytime highs near 90 degrees with overnight lows in the lower to mid 80s and dew points in the mid to upper 70s. Of course, temperatures may fall into the upper 70s where any showers and storms move over. TROPICS: The National Hurricane Center (NHC) continues to monitor 2 areas across the Atlantic Ocean with none of these systems currently posing a threat to the Keys. The area across the Eastern Tropical Atlantic now has a 10% chance of development over 48 hours and 50% chance of development over the next 7 days. && .PRELIMINARY POINT TEMPS/POPS... Key West 83 90 83 90 / 10 20 50 50 Marathon 83 91 83 91 / 20 30 50 50 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...LIW Aviation/Nowcasts....LIW Data Acquisition.....LIW Visit us on the web at weather.gov/key Follow us on Facebook and X at: www.facebook.com/nwskeywest www.x.com/nwskeywest