Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
832 FXUS62 KKEY 240839 AFDKEY Area Forecast Discussion National Weather Service Key West FL 439 AM EDT Mon Aug 24 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... - Conditions remain somewhat favorable for an island cloud line and associated waterspouts this afternoon. - Slight chance of showers and thunderstorms today and tonight, with increasing shower and thunder chances thereafter. - Highs near 90 and dewpoints in the mid to upper 70s suggest afternoon heat indices will peak at 105 to 108 degrees. && .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. && .MARINE... Issued at 439 AM EDT Mon Aug 24 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, a split ridge pattern remains in place across the Florida Keys coastal waters. East to southeast breezes will become more established from this morning through Thursday, becoming generally gentle, at times moderate during the overnight hours, as North Atlantic ridging builds westward. Shower chances will gradually increase as the week progresses. && .AVIATION... (06Z TAFS) Issued at 439 AM EDT Mon Aug 24 2026 VFR conditions are expected to persist at both EYW and MTH terminals through the TAF period. Near surface winds will remain mostly southeasterly through the late afternoon before shifting to the east to southeast for the evening and overnight hours. In addition, a slight chance of showers and thunderstorms remains in the forecast for today along with a cloud line possible. Due to the uncertainty in timing and placement, VCSH was not included in the TAF. && .CLIMATE... On this day in 2016, the daily record rainfall of 2.55" was recorded in Key West. Rainfall records for Key West date back to 1871. On this day in 1995, the daily record rainfall of 8.33" was recorded in Marathon. This is also the wettest day ever recorded during the month of August. Rainfall records for Marathon date back to June 1950. OF NOTE In 1992, Hurricane Andrew struck south Miami-Dade County, devastating Homestead and causing major damage in the Miami metro area. The southern eyewall brushed the Ocean Reef area in the extreme Upper Keys, causing significant damage to numerous buildings. In terms of lowest central pressure, this was the fifth-most intense hurricane to make landfall in the United States since 1851. && .PRELIMINARY POINT TEMPS/POPS... Key West 90 83 90 83 / 10 10 30 50 Marathon 91 83 91 83 / 20 20 30 50 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....MJV Data Acquisition.....MJV Visit us on the web at weather.gov/key Follow us on Facebook and X at: www.facebook.com/nwskeywest www.x.com/nwskeywest