Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
950 FXUS62 KKEY 101757 AFDKEY Area Forecast Discussion National Weather Service Key West FL 157 PM EDT Thu Jul 10 2025 ...New AVIATION... .AVIATION... (18Z TAFS) Issued at 121 PM EDT Thu Jul 10 2025 VFR conditions will prevail at both island terminals through 18z Friday afternoon. However, scattered showers and thunderstorms will possibly develop in the vicinity of the terminals, especially after 06z this evening. Confidence in convective development, timing, and evolution permits not including mention in the TAFs at this time, although this will be reevaluated at the 00z TAF issuance. Near- surface winds will remain out of the east to southeast, modestly freshening overnight. && .PREV DISCUSSION... Issued at 1030 AM EDT Thu Jul 10 2025 Although hard to discern in satellite-derived low- and mid-level vorticity products, visible and infrared satellite imagery clearly depict a weak easterly wave traversing the Florida Keys at this late morning hour. KBYX Doppler radar has been lighting up in the vicinity of the Upper Keys for the past several hours, suggesting the axis of the wave currently lies somewhere in the vicinity of the eastern Middle Keys. Surface wind observations also support this analyzed location of the wave, with winds across the Upper Keys from the east to southeast, and winds across the drier Lower and Middle Keys from the northeast to east. Temperatures range from the middle to upper 80s in the dry communities, compared to upper 70s to near 80F in the rain-cooled Upper Keys locations. The 12z morning sounding at KEY highlighted an uninhibited mixed layer parcel trajectory. Coupled with the passing easterly wave, rain and thunder chances are expected to remain elevated through the afternoon, initially to the east, then eventually in the western Keys islands and marine zones. With the light northeasterly flow and the lack of cloud coverage currently in the Lower and Middle Keys, there is also a window for an island cloud line to form over the next several hours ahead of the wave axis passage, and we are on alert for the potential for waterspouts associated with any developing cloud streamers. Combining all of this analysis supports and least 50/50 rain and thunder chances for the Florida Keys through late this afternoon. Outside of minor adjustments to the wind directions for the next several hours until the wave axis fully propagates through, no changes proposed for this late morning forecast iteration. && .FORECAST... Issued at 515 AM EDT Thu Jul 10 2025 As moisture becomes abundant and a easterly wave moves into the area, showers will increase in coverage. Model guidance suggests that things will get more active in the CWA late this morning and into the afternoon hours. The primary hazards with any thunderstorm will be cloud to surface lightning strikes and locally gusty winds. Apart from convection, breezes will start to gradually increase this afternoon, as the pressure gradient tightens, resulting in a period of gentle to moderate breezes. Tonight, shower activity will become more sparse but still at a chance through Friday. Over the weekend, surface high pressure and persistent ridging aloft will continue to dominate the synoptic pattern across the Florida Keys, maintaining east to southeast flow. GEOS-FP Dust Aerosol Optical Thickness guidance indicates a Saharan Air Layer plume will move into the region, introducing a drier airmass and suppress a majority of convection. PoPs have been slightly lowered over the weekend, though a chance of showers still remains until confidence increases of the extent of the dry air from SAL. By early next week, a shift in the pattern is anticipated as the mid-level ridge gradually lifts north and a tropical easterly wave approaches from the east. Given it is in the extended, PoPs have been maintained at chance and will be adjusted as confidence increases. && .MARINE... Issued at 1030 AM EDT Thu Jul 10 2025 No watches, warnings, or advisories are currently in effect for the Florida Keys waters. From synopsis, a weak tropical wave will continue to push westward through the Florida Keys coastal waters this afternoon and tonight. A moisture plume associated with the wave, in conjunction with modestly freshening east to southeasterly breezes, will support elevated shower and thunder coverage through Friday. A wave of Saharan dust will move in over the weekend, resulting in reduced rain and thunder chances. Winds will subside to light to gentle for the weekend into early next week. && .PRELIMINARY POINT TEMPS/POPS... Key West 91 82 92 82 / 40 40 40 30 Marathon 89 82 89 82 / 50 50 40 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...BT Aviation/Nowcasts....BT Data Acquisition.....BT Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest