Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
587 FXUS62 KKEY 021539 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1039 AM EST Tue Dec 2 2025 ...New DISCUSSION, MARINE, AVIATION, PREV DISCUSSION... .KEY MESSAGES... -Moderate east to southeast breezes will gradually slacken and veer to the south to southwest. -Breezes will continue to slacken and veer as we head into the middle of the week, and some areas of fog may develop over local waters by early Wenesday morning. -A benign forecast is anticipated for much of the week with rain chances near nil, increased humidity initially, before a dip with frontal passage mid week before increasing again by the weekend. Temperatures will also remain above normal early week, near normal mid week, and then above normal again by the weekend. && .DISCUSSION... Issued at 1039 AM EST Tue Dec 2 2025 An abrupt change in winds over the last 12 hours for the Florida Keys. A high pressure is moving into Canadian Maritime Provinces. Meanwhile, a complex surface low extends from the Carolina`s coast to the Florida Panhandle. This has resulting in winds quickly clocking around the northeast to east last night, to south to southwest this morning. KBYX radar and satellite imagery over the same 12 hour period shows this fast change. A land breeze that was oriented nearly west to west, came off Cuba last night and then pivoted northeast with a new orientation of northwest to southeast. This was more reminiscence of late spring or summertime pattern. A few isolated showers did develop along this Cuban boundary but only a very few selected island communities saw rain this morning. Otherwise, a pre-frontal line of showers is entering our outer Gulf waters, including the waters surrounding the Dry Tortugas. The Keys themselves should remain in a relatively dry slot through this afternoon. Therefore, will leave rain chances very low 10 percent or less, best in the Upper Keys early. As we go into this evening, some of the Hi-Res CAMs are showing this line trying to move through the island chain overnight. We will re- evaluate this this afternoon as it could have bigger implications for potential fog. For now, have made no changes to the going forecast. && .MARINE... Issued at 1039 AM EST Tue Dec 2 2025 High pressure across the area will slide northeast and further away from the Florida Keys. Meanwhile, a developing storm system on the heels of this high. The combination of which will result in a weakening of the pressure gradient and slackening of winds through the afternoon and overnight. A corresponding cold front is expected to press through the Keys early Wednesday morning. In the wake breezes will freshen out of north to northeast Wednesday. Another surface high builds back in following the front with gentle broadly southern breezes returning in time for the weekend. && .AVIATION... (15Z TAFS) Issued at 1039 AM EST Tue Dec 2 2025 VFR conditions expected through the forecast period with southerly winds becoming west and eventually northwest this evening and overnight. Winds will subside and we will have to monitor for either potential patchy fog or a very low stratus deck. Will re- evaluate for the next TAF package. && .PREV DISCUSSION... Issued at 440 AM EST Tue Dec 2 2025 A relatively uneventful early morning is underway across the Keys on this second day of December. KBYX radar detects a couple boundaries drifting through our CWA with a few shallow showers bubbling near the Dry Tortugas and the 409 Humps. GOES-19 Nighttime Microphysics imagery paints a similar picture with a scattered field of stratocumulus between the rope clouds notating convergence boundaries in our area. Looking north outside of our area, a mass of cloud cover associated with a trough marching towards the Eastern Seaboard is painted over much of southeast CONUS. The surface high located just ahead of this feature continues to promote moderate southeast to south breezes across the Reef. Meanwhile, temperatures are a touch warmer than this time yesterday with values in the upper 70s but feeling just as steamy with dew points persisting in the lower 70s. The short term forecast is one describing a transition between patterns. Deep layer troughing over the Ohio River Valley will continue to press east shifting the surface high over the Eastern Seaboard into the Atlantic. This will result in our moderate southeast breezes slackening and veering to the southwest by the end of the day. Tonight the trend will continue as winds continue to turn to the northwest ahead of the associated surface front lumbering southeast through mainland Florida and the western Gulf. While rain chances still float around near nil, warm temperatures and moist dewpoints over cooler waters is a recipe for some fog development north of the island chain early tomorrow morning. This is further enhanced by a northwesterly wind direction that will help advect already formed fog from mainalnd`s coastline. Later on Wednesday, the cold front is progged to scrape through our area. This will bring a small and brief respite to ongoing mild conditions. Low temperatures are currently expected to dip to near 70 Thursday morning with dewpoints falling to the upper 60s. Of course, this weak frontal passage`s influence will be short lived as southerly winds and warmer temperatures quickly return in time for the weekend. As the moist air mass never really gets cleared out, slight rain chances will return to the Keys as winds return to their more familiar southeasterly positions. Though, if extended guidance is to be believed, another cold front (this time somewhat stronger) is set to sweep through in the middle of next week drying things out once again. We just might be seeing some "winter" weather here then, but stay tuned for updates. && .PRELIMINARY POINT TEMPS/POPS... Key West 82 71 79 70 / 10 10 10 0 Marathon 82 71 78 70 / 10 10 0 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