Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
276 FXUS62 KKEY 100841 AFDKEY Area Forecast Discussion National Weather Service Key West FL 441 AM EDT Fri Oct 10 2025 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... -Peak rain chances today (90%), then slightly decreasing rain chances tonight (80%) as the non-tropical low begins to pull away from the area. -A Coastal Flood Advisory remains in effect for all Florida Keys. The combination of the current King Tide cycle and persistent bouts of rainfall will support additional flooding over roadways and low lying lots. Coastal flooding will likely continue into the weekend. -A weak cold front is anticipated to move through the Keys over the weekend. This will usher in drier air offering the first taste of Florida Fall to the Keys into early next week. && .DISCUSSION... Issued at 438 AM EDT Fri Oct 10 2025 The active pattern remains in place across the Keys. KBYX radar has remained active all night with scattered to numerous showers with some thunderstorms from time to time. The radar loop depicts a cyclonic flow across the area. Showers were moving from northwest to north across the eastern portions of the area with the activity across the western areas moving from west to northwest. Looking even more closely, we can potentially depict where the center of the low pressure. The activity just outside of the Keys to the north of western Cuba is moving southwest to south, even slightly southeasterly. MRMS data shows estimated rainfall accumulations of generally a trace to a quarter of an inch overnight, though the heaviest rainfall has so far been over the marine area. Temperatures along the Island Chain are in the upper 70s to near 80 degrees with dew points in the mid 70s. Marine platforms around the Keys are observing southeast to south breezes near 5 knots. .FORECAST... The aforementioned low pressure system will continue moving north to northeast today while slowly strengthening. It will continue becoming better organized as it moves north northeastward to a place off of the Mid-Atlantic coast by Sunday. GOES East Total Precipitable Water (TPW) shows PWAT values remain quite juicy early this morning. Most of the Keys are seeing PWAT values above 2 inches even approaching 2.3 inches in some instances. In addition, an upper trough continues to dig southward across the southeast Gulf today and tonight. At the surface, this will induce a surface low, which we are already seeing signs of when looking at radar. We also have ample instability in place with the 00z sounding last evening showing almost 2000 J/kg of CAPE. Therefore, all the ingredients are there for today to be quite active in terms of more widespread shower and thunderstorm coverage. We don`t expect any of this activity to be strong, more garden variety for the thunderstorms with the typical gusty winds. Therefore, PoPS were increased for today and tonight from 80% --> 90% and then 70% --> 80% respectively. As this low continues to develop and strengthen while moving north northeastward, it will begin to send a cold front southward along the Florida Peninsula. There still remains some uncertainty as to exactly how far south the front will go. One thing to remember is that it is still early on in the season for a cold front to fully push through the Keys, though it is still possible under the right conditions. Latest thinking is the front may just clear the Island Chain and then remain over the Straits for a few to several days. Initially, drier air will make it into most if not all of the Keys for the second half of the weekend into early next week, though some lingering moisture is possible in the low levels of the atmosphere. 10% PoPs are in the forecast along with no thunder as a result. Towards the middle to latter part of next week, there are some signals of this front lifting back as a warm front. If this occurs, moisture may return to the area along with some instability. For now, PoPs remain at 20% for Monday night through Thursday with no thunder chance. Stay tuned. && .MARINE... Issued at 438 AM EDT Fri Oct 10 2025 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, a non- tropical surface low located over western Cuba will continue to slowly drift northward today and then north northeastward tonight. This will support bouts of elevated rain and thunder chances. The low will initially support light to gentle southeast to south breezes this morning. However, as the low moves north northeastward, breezes will veer to the northwest to north over the weekend. Low pressure will continue organizing and strengthening as it heads northeastward adjacent to the Mid- Atlantic coast. As it does this, it will drive an early season cold front towards the Keys, further shifting winds to the north to northeast. Northerly swells will be possible in our western marine zones today and through the weekend due to the influence of the low pressure system. && .AVIATION... (06Z TAFS) Issued at 438 AM EDT Fri Oct 10 2025 VFR conditions are expected to mostly prevail at the terminals through the TAF period. That said, periods of showers and an occasional thunderstorm are likely throughout the period. This is addressed via continuous inclusion of VCSH for the entire period. It is likely that CIGs and visibility may be reduced to MVFR or IFR when these occur at the terminals, but given the uncertainty of timing, elected to only address this via TEMPO before 12z. Later categorical changes will be addressed via amendment and routine TAF issuances. Southeast winds 5 to 10 knots will become south to southwest by this afternoon. && .CLIMATE... On this day in Keys Weather History, in 1888, the daily record low temperature of 66F was recorded at Key West. Temperature records for Key West date back to 1872. && .PRELIMINARY POINT TEMPS/POPS... Key West 84 78 86 78 / 90 80 50 20 Marathon 86 76 86 76 / 90 80 50 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 6 AM EDT Saturday for FLZ076>078. GM...None. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....MC Data Acquisition.....MC Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest