Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
506 FXUS62 KKEY 310833 AFDKEY Area Forecast Discussion National Weather Service Key West FL 433 AM EDT Mon Aug 31 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... - Chance of showers and thunderstorms expected today and tonight. There is also the low risk for a cloud line this afternoon. - Mainly light to gentle broadly easterly breezes will continue through the first half of the week. - The Remnants of Dolly remain near Puerto Rico and the Virgin Islands and may bring a period of much higher rain chances by the middle of the week. && .DISCUSSION... Issued at 433 AM EDT Mon Aug 31 2026 CIMSS products continues to show mean layer ridging dominating much of the Atlantic as well as the ARK-LA-TEX region eastward through the Southeast U.S. Troughing continues for the West Coast with more of a zonal flow riding over the top of the ridge across the Great Lakes and the Northeast U.S. At the surface, the western side of the high over the Atlantic maintains control across the Keys. Marine observation platforms surrounding the Island Chain are recording mainly east breezes of 5 to 10 knots as a result. GOES 19 Total Precipitable Water (TPW) products shows abundant moisture across the area with estimated PWATs ranging from 1.85 to 2.4 inches. KBYX radar has remained somewhat active overnight with a few showers initially across the Upper Keys and the Straits of Florida to the south of the Lower Keys. However, over the last hour or two, additional showers developed in the vicinity of the Dry Tortugas across the SE Gulf while the earlier activity across the Upper Keys and Straits fizzled out. Temperatures along the Island Chain are in the lower to mid 80s and dew points are in the upper 70s to near 80 degrees. .FORECAST... Ever so slightly drier air has moved into the Keys early this morning. Therefore, while we still expect showers and thunderstorms, we don`t expect the activity to be as widespread for today and tonight. Therefore, PoPs were lowered slightly to 30% for this frame. The theme remains the overall same though with an Atlantic ridge continuing to extend its western periphery into the Keys. Global and numerical model guidance remain in agreement through at least Tuesday night for a slightly drier period from today through Tuesday night. The PoPs are as follows 30% tonight, 40% Tuesday, and 30% for Tuesday night. Also, with a slightly lighter wind regime today, there is the potential that a cloud line may try to develop during the afternoon, though, this is low confidence at this time. It may happen again Tuesday afternoon as well. With that said, the forecast for mid to late week while still looking interesting isn`t looking as favorable as it did before. Global and numerical guidance virtually show the Remnants of Dolly totally fizzling out as it moves into Cuba. However, the northern fringe of the moisture associated with it may graze the Keys Wednesday/Thursday time frame. The remnants and its moisture will continue moving west northwest gliding along the northern fringe of Hispaniola and eventually moving right into the eastern side of Cuba. It appears that the northern fringe of the moisture associated with Dolly reaches the Keys sometime Wednesday and continues to affect the region through Thursday/Thursday night before continuing northwestward into the Gulf. Therefore, likely Pops are in the forecast for this time frame at 60%. It turns out the main takeaway for this time frame will be to potentially expect slightly friskier showers and thunderstorms and an increase in cloud cover. Behind the remnants of Dolly, moisture will remain, just not as deep as the mid to late week time frame. Rain chances return back to chances (40-50%), though, still remain elevated for late week and into the holiday weekend. After all, it is September at this point. The Keys remain on the western periphery of the Atlantic ridge through much of the week. This will continue to yield to peaking and lulling breezes through the middle part of this week. However, the wind direction will also follow suit with east to southeast breezes during the early morning to early afternoon hours followed by northeast to east breezes in the mid to late afternoon into the early overnight hours. Breezes will stabilize a little bit more towards the end of the week with mainly east to southeast light to gentle breezes anticipated. Daytime highs will continue to be near 90 degrees with overnight lows in the lower to mid 80s, cooler in and near shower and storms. Dew points will remain soupy in the mid to upper 70s. September starts in less than 24 hours and Florida will continue to live up to its name for this time of year with daily rain chances. TROPICS: The National Hurricane Center (NHC) continues to monitor two areas for potential tropical cyclone development. The first is near Puerto Rico and the Virgin Islands (Remnants of Dolly) which has a low or near 0 percent chance of development through 48 hours and a low or 20 percent chance of development through the next 7 days. The second area being watched for tropical cyclone development is currently in the Northern Gulf of America (Invest 97L). This system has a high or 705 chance of tropical development through both the next 48 hours and 7 days. Both of these systems currently pose no threat to the Florida Keys, though, Dolly`s remnants may very well bring an increase in rain chances to the Keys. && .MARINE... Issued at 433 AM EDT Mon Aug 31 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, the western periphery of an Atlantic high remains in control of the Keys for the next several days. Therefore, expect continued peaking and lulling breezes. The direction will also shift over the next few days with east to southeasterly breezes overnight and in the morning with northeast to east breezes late afternoon and evening. In addition, the overall flow will keep deep moisture in place across the region with daily chances of showers and thunderstorms. Locally hazardous winds and seas are expected in the vicinity of thunderstorm activity. && .AVIATION... (06Z TAFS) Issued at 433 AM EDT Mon Aug 31 2026 VFR conditions are expected to persist at both EYW and MTH terminals through the TAF period. Near surface winds will remain east to southeast into the early to mid afternoon hours before shifting to the northeast to east for the late afternoon through early overnight hours. Chances of showers and thunderstorms remain for today, though not nearly as widespread as previous days. There is also the low risk for a potential cloud line this afternoon. && .CLIMATE... On this day in 1872, the daily record rainfall of 1.54" was recorded in Key West. Rainfall records for Key West date back to 1871. On this day in 1962, the daily record rainfall of 2.24" was recorded in Marathon. Rainfall records for Marathon date back to June 1950. && .PRELIMINARY POINT TEMPS/POPS... Key West 90 83 90 83 / 30 30 40 30 Marathon 90 82 90 82 / 30 30 40 30 && .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