Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
422 FXUS62 KKEY 172044 AFDKEY Area Forecast Discussion National Weather Service Key West FL 344 PM EST Mon Nov 17 2025 ...New MARINE, AVIATION, PREV DISCUSSION... .KEY MESSAGES... -Light to gentle breezes, potentially variable this afternoon, will continue through tonight before slowly freshening and becoming northeast to east heading into Tuesday. -Dry air will limit shower development through much of the week. -Another day of slightly below normal temperatures today with slow warming of temperatures to near 80F by mid week and then lower 80s for late week into the weekend. && .MARINE... Issued at 314 PM EST Mon Nov 17 2025 A high pressure system currently over the Lower Ohio Valley will slide east into the Mid-Atlantic through Tuesday while slowly strengthening. This will promote freshening northeast to east breezes for mid week. This high will continue moving into the western North Atlantic elongating and maintaining strength as it does so. This will allow for continued moderate to fresh breezes through late week. && .AVIATION... (18Z TAFS) Issued at 314 PM EST Mon Nov 17 2025 VFR conditions will prevail through the overnight and into tomorrow morning. Light and at times variable winds will decidedly become northeast overnight and gradually freshen through Tuesday afternoon. && .PREV DISCUSSION... Issued at 430 AM EST Mon Nov 17 2025 Another quiet and cool night is ongoing across the Florida Keys. Radiational cooling has been at the forefront as the Big Pine Key RAWS has dipped down to a very chilly 57 degrees early this morning with the potential for this to dip another degree or two. Elsewhere, temperatures along the Island Chain are in the mid to upper 60s and dew points are in the lower to mid 60s. Weak high pressure remains in control throughout the Keys. This is promoting northwest to north breezes of 5 to 10 knots at marine platforms surrounding the Keys with Island Chain communities either light and variable or even calm. The weak flow and basically calm winds can be attributed to the cause for substantial cooling on Big Pine Key. Otherwise, moisture is meager with GOES East Total Precipitable Water (TPW) estimating PWAT values of 0.7 to 0.9 inches throughout the area. The 00z evening sounding was also quite dry through the profile and measured a PWAT of 0.79 inches which was slightly higher than last night. This has led to KBYX radar not detecting any shower activity overnight. .FORECAST... Quiet and nice weather continues for the Keys through much of this week. A weak and flat ridge will dominate much of Florida today. This will keep dry air entrenched throughout the area and much of the state leading to nil rain chances for the foreseeable future. The exception might be over the Straits where slightly deeper moisture could lend to a shower or two. Light to gentle breezes are expected to continue through tonight. Daytime highs are expected to be in the upper 70s to near 80 degrees with overnight lows in the upper 60s. There is the potential for another substantial radiational cooling night on Big Pine before winds increase tonight. With the light winds and generally clear sky, there is the likelihood for radiational cooling across the Island Chain tonight before winds begin to increase. Any cooling tonight is most likely expected to occur in the evening before the winds begin to increase overnight. Another high pressure moving across the Southeast U.S. will lead to a strengthening of the pressure gradient across the Keys. This will promote freshening northeast to east breezes for mid to late week. This may also lead to a period of breezy conditions once again for the Island Chain, though, latest guidance is backing off on this solution. Moisture remains meager keeping rain chances near nil through the extended. As winds also shift to the east, this will lead to slowly increasing humidity and temperatures with daytime highs creeping back into the lower 80s by late next week. && .PRELIMINARY POINT TEMPS/POPS... Key West 69 79 71 80 / 0 10 10 0 Marathon 69 79 72 80 / 0 10 10 0 && .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 Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest