Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
016 FXUS62 KKEY 030913 AFDKEY Area Forecast Discussion National Weather Service Key West FL 413 AM EST Wed Dec 3 2025 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... -Some areas of fog may develop over local waters early this morning, and some of this fog may cross the island chain. -Light to gentle breezes will veer from northerlies to north to northeasterlies. Freshening breezes are expected Thursday and Friday with a peak of moderate easterly breezes. -The next opportunity for an unsettled pattern looks to occur sometime over the Sunday and Monday timeframe. && .DISCUSSION... Issued at 412 AM EST Wed Dec 3 2025 December is here at last, which includes chaotic winter weather patterns across the United States. Over the Florida Keys, this takes the shape of cold frontal passages, veering winds, and even occasional early morning fog. GOES East nighttime microphysics observations north of the island chain highlight fractured stratus clouds along Lake Okeechobee and stretching into the Gulf. Those clouds indicate a cold front meandering towards the Florida Keys. However, that frontal system is still at least half a day out. Winds early this morning across the island chain are light and variable. Radiational cooling is allowing temperatures to fall into the lower 70s across the CWA, and sensors on larger islands are measuring lows in the upper 60s. Dew points continue to linger in the upper 70s. Early morning radiation fog is a concern for Keys residents, but the threat does not end with sunrise. Environmental conditions do support a potential fog event for the Bayside waters and the island chain. Relative to 400 AM, the fog layer has not formed, but fog develops very quickly over the Keys. Brace for vehicles to be drenched in condensation this morning. In the short term, conditions along the island chain will be close to persistence. Temperatures will remain slightly above normal through the week. Increasing dew points indicate the weather will remain very muggy. Winds are the shifting variable; expect to see winds freshen tomorrow and veer northeasterly. However, this pattern will not last. High pressure will set up over the southeastern CONUS during the second half of the work week. In the northern half of the country, a polar vortex located over Canada`s maritime provinces will help fuel a parade of `clipper` lows along the Canadian border into the Great Lakes. While this occurs, a shortwave trough over the Four Corners will slowly make its way across the continental divide towards the Plains. All these patterns become relevant for the Florida Keys by the end of the week when the shortwave trough develops a distinct surface low along the Gulf coast. For the Keys, winds over the coastal waters are forecast to continue veering to southeasterly. Dew points may rise to the mid 70s across the island chain before a cold front sweeps towards the CWA early next week. Keep in mind, this is about five to six days out and statistical guidance may change. What matters the most at this time is that breezy or windy conditions are not anticipated within the next seven days. && .MARINE... Issued at 412 AM EST Wed Dec 3 2025 No watches, warnings, or advisories are currently in effect for the coastal waters of the Florida Keys. From synopsis, a cold frontal system extending from Cape Hatteras to the middle of the Gulf will meander across the Florida Keys today and tonight. Areas of patchy fog may develop early this morning over the bayside waters. Breezes will veer northeasterly and freshen tonight and Thursday. High pressure building over the Ohio Valley will cause winds to veer southeasterly and slacken over the weekend. Another frontal passage is possible towards the beginning of next week. && .AVIATION... (06Z TAFS) Issued at 412 AM EST Wed Dec 3 2025 Light northwesterly breezes and moist conditions early this morning may allow for the formation or advection of patchy fog near the island chain. While more likely at MTH, this may cause bouts of IFR or worse VIS and CIGs at either terminal for a couple hours. Fog is not currently observed in our area so have opted to keep impacts in the TAFs lighter until it maybe forms. If this does come to pass, any sign of fog is expected to dissipate within a few hours following sunrise. Afterward, VFR conditions are expected to prevail with near surface winds turning to the north at 5 to 10 knots. && .CLIMATE... On this day In 2018, the daily record warm low temperature of 80F was recorded at Key West International Airport. Temperature data for Key West dates back to 1872. && .PRELIMINARY POINT TEMPS/POPS... Key West 80 70 81 73 / 0 0 0 10 Marathon 80 71 80 73 / 0 0 0 10 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...AJP Aviation/Nowcasts....JAM Data Acquisition.....JAM Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest