Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
787 FXUS62 KKEY 101819 AFDKEY Area Forecast Discussion National Weather Service Key West FL 219 PM EDT Fri Oct 10 2025 ...New AVIATION... .KEY MESSAGES... -Numerous showers and scattered thunderstorms will support potential bouts of freshwater flooding through tonight. -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 by late Saturday, and also bring the first taste of Florida Fall to the Keys into early next week. && .AVIATION... (18Z TAFS) Issued at 152 PM EDT Fri Oct 10 2025 Widespread showers in the vicinity of the terminals supports a prevailing SHRA period through late this evening at both EYW and MTH island terminals. Any stronger thunderstorm will be handled with possible short-term amendments, including TEMPO groups. A lull in overall thunderstorm activity is expected for this period, before a period of recharging overnight. Have elected to include a general VCSH for that period due to uncertainty in timing and evolution, with a PROB30 to account for enhanced thunder chances through 18z Saturday afternoon. && .MARINE... Issued at 1130 AM EDT Fri Oct 10 2025 From synopsis, a low- and mid-level trough 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 system will develop into an area of low pressure off the coast of Florida, with southeasterly light to gentle breezes gradually backing to the northwest to north over the weekend. The low pressure system 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. && .PREV DISCUSSION... Issued at 1130 AM EDT Fri Oct 10 2025 An extremely active late overnight and morning for the Florida Keys and the adjacent nearshore and offshore marine zones. Slow- moving, training showers and thunderstorms set up over portions of the Lower and Middle Keys, with widespread rain gauge and MRMS- derived totals of 2-4", with isolated amounts up to 6" in these areas. KBYX and KMTH radar reflectivity trends have been downward over the past couple of hours along the Island Chain allowing Flood Advisories to expire, with the strongest activity now displaced in the distant Straits of Florida and to the northwest in the offshore Gulf waters. Owed to the widespread rainfall, temperatures remain in the mid to upper 70s across the Island communities. For the balance of today, an upper-level trough impinging from the east will interact with a stagnant inverted low- and mid-level trough across the Keys. This will support continued large-scale ascent, although convective potenital instability will likely be stinted until recharging can occur later this evening and overnight. The forecast calls for continued showers this afternoon, with potential stronger thunderstorms redeveloping this evening or overnight. No changes proposed to the inherited forecast at this time. && .FORECAST... Issued at 438 AM EDT Fri Oct 10 2025 A 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. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 6 AM EDT Saturday for FLZ076>078. GM...None. && $$ Public/Marine/Fire...BT Aviation/Nowcasts....AJP/BT Data Acquisition.....AJP Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest