Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
068 FXUS62 KKEY 141918 AFDKEY Area Forecast Discussion National Weather Service Key West FL 318 PM EDT Mon Sep 14 2026 ...New DISCUSSION, MARINE, AVIATION, PREV DISCUSSION... .KEY MESSAGES... - Near to slightly-above normal rain chances in the short term is expected to give way to considerably higher rain chances later in the work week. - Winds are expected to trend upwards over the next several days, likely peaking in the moderate to fresh range around mid week. - Heat index values will range from 100-108 degrees daily, with little relief from the muggy conditions overnight. Know the signs of heat stress, take frequent breaks, and stay hydrated. && .MARINE... Issued at 310 PM EDT Mon Sep 14 2026 Light and variable breezes will continue through this afternoon and into the early evening. As a continental highly slowly moves into the eastern half of the U.S., we can expect breezes to become more easterly tonight and become light to gentle. As this high builds southward towards our area over the next couple of days, expect breezes to peak in the moderate range late Tuesday and late Wednesday. Near normal rain chances will trend considerably upwards through mid week as broad troughing and increasing moisture moves in from the east. && .AVIATION... (18Z TAFS) Issued at 310 PM EDT Mon Sep 14 2026 VFR conditions have returned, however, the cloudline across the Lower Keys continues to cycle in intensity and occasional showers will continue to develop. These showers will bring the potential for MVFR or brief IFR conditions this afternoon. Additional moisture will gradually filter in from the east over the next 12 to 18 hours, maintaining an enhanced risk for showers and thunderstorms. Confidence on when exactly we may see thunderstorms return is very low at this time. && .PREV DISCUSSION... Issued at 400 AM EDT Mon Sep 14 2026 A mid latitude trough aligned along the Atlantic coast is holding an Atlantic ridge at bay, off to our east. As a result, the local pressure gradient is sloppy and resulting in light generally east to southeasterly breezes. Meanwhile, weak lower to mid level ridging spans the Florida Peninsula. While last evenings sounding indicated modest CAPE with high precipitable water around the 90th percentile at 2.21 inches, there was a hint of lower level inhibition. Much of this lower level inhibition was likely caused by a gulf outflow boundary that swept through our area this evening. That said, shower activity across the Keys has been nearly absent over the past several hours. The local pressure gradient will remain poorly defined today with a split ridge across Florida. As a result, while surface winds will try to be light out of the east to southeast, a large portion of our forecast area will likely become variable and dominated by mainland daytime heating effects. Forecast soundings indicate weak low level inhibition will persist, along with modest CAPE. Rain chances are expected to be near normal, but highlight the potential for mainland seabreeze activity to roll southward into the Upper Keys later this afternoon and evening. No trend in temperatures are expected and highs will remain near 90, lows in the lower 80s, and dew points in the mid to upper 70s. Over the following few days, a robust continental high cell will spread southward through the eastern United States as the mid latitude trough pushes out into the Atlantic. This high will gradually bolster the local pressure gradient and northeast to easterly breezes will steadily freshen through this period. Expect winds to peak in the moderate to possibly fresh range late Tuesday into late Wednesday. The precipitation story is complicated as the tail end of the mid latitude upper trough is expected to pinch off east of the mid Atlantic Coast and interact and absorb a TUTT cell near Hispaniola. This will setup a broad trough off to our east. All this is then expected to advance westward through Florida and the Keys. Consequently, deep layered moisture is expected to climb sharply through the mid and latter part of the week. This along with falling mid level heights due to the retrograding deep layered low complex should point towards increasing PoPs. For now will mostly retain the currently advertised increasing trend in PoPs for the week. && .PRELIMINARY POINT TEMPS/POPS... Key West 82 92 81 91 / 30 30 50 50 Marathon 82 90 82 89 / 30 40 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