Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
087 FXUS62 KKEY 011533 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1033 AM EST Mon Dec 1 2025 ...New DISCUSSION, MARINE, AVIATION, PREV DISCUSSION... .KEY MESSAGES... -Gentle to moderate northeast to east breezes this afternoon will become east this evening before shifting further to the southeast by early Tuesday morning. -Breezes will continue to clock around the compass while continuing to slacken through Wednesday as the next frontal system approaches due to developing low pressure along the Mid- Atlantic to New England coastlines. -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 1032 AM EST Mon Dec 1 2025 It has been a quiet, but sticky morning for the Florida Keys. KBYX radar has been and continues to track scattered showers across the southwestern Straits of Florida. These showers are moving west northwest towards the extreme Southeast Gulf Basin. There was some lightning early in the morning, but once sunrise occurred, we have not observed any additional lightning. Across the region, we are under a nearly zonal flow as we are just far enough away from a high pressure moving the Great Lakes region and a developing coastal low pressure system off the New England States. This is keeping us under generally east winds of 10 to 15 knots over our waters or around 10 mph for the island chain. Dry air in the low levels will hinder not only cloud development but the threat for showers. Shower activity through the afternoon will be highly limited to the Straits of Florida, where a combination of convergence, instability, and moisture is maximized. Therefore, made no adjustments to the going forecast for the island chain, keeping mostly sunny skies and dry weather. No changes were made either to the coastal zones at this time. && .MARINE... Issued at 1032 AM EST Mon Dec 1 2025 Another large area of high pressure currently located over the Lower Great Lakes region will continue moving eastward through the afternoon. This will continue to promote gentle to moderate northeast to east breezes shifting to southeasterly by Tuesday morning as the high shifts farther east. A developing storm system on the heels of this high will result in a weakening of the pressure gradient across the Keys through early Wednesday. Breezes will also clock around the compass going from southeast to south Tuesday to northwest to north by early Wednesday. Its corresponding cold front is expected to press through the Keys mid to late week resulting in freshening north to northeast breezes. && .AVIATION... (15Z TAFS) Issued at 1032 AM EST Mon Dec 1 2025 VFR conditions will prevail under gentle easterly breezes today. Expect a gradual clocking of winds, coming out of the southeast by the evening and overnight. && .PREV DISCUSSION... Issued at 428 AM EST Mon Dec 1 2025 The humidity is back at least for the next few days across the Florida Keys. Temperatures along the Island Chain are in the lower to mid 70s and dew points are in the lower 70s. This is making it feel quite humid and sticky to start the new and final month of 2025 (December). KBYX radar has been detecting isolated to scattered showers all night. The heaviest and most widespread activity has been across the southwestern distant Straits of Florida with more isolated activity elsewhere, mainly south of the Island Chain. However, occasionally a couple showers have been able to affect a few island chain communities, mostly in the Middle and Upper Keys. GOES 19 Nighttime Microphysics imagery shows some low level clouds throughout the Keys with an area of high clouds across the southwestern Straits moving southeastward towards Cuba. Another large surface high pressure system is located over the Lower Great Lakes region. This is promoting gentle to moderate northeast to east breezes at marine platforms surrounding the Island Chain. .FORECAST... The aforementioned high pressure will continue to move to the east over the next 24 hours. Therefore, expect mainly gentle to moderate northeast to east breezes to continue through this evening before shifting to the east to southeast and further slackening overnight through Tuesday night. Moisture also continues to lurk over the area early this morning. GOES 19 Total Precipitable Water (TPW) products shows estimated PWAT values of 1.4 to 1.6 inches throughout the Keys. While moisture is lingering, most of the shower activity has remained over the marine area. This is expected to be the main theme for today resulting in a dry forecast for the Island Chain. However, we do keep the rain chances over the Straits of Florida, especially the west side. As this high continues moving off to the east, a storm system will begin to quickly develop on its heels. This system will become a Nor`easter as it moves northeastward to a place just off the New England coastline by Tuesday evening. However, the item of interest for the Keys will be another frontal boundary which is expected to approach and then move through the Keys sometime mid week. However, before we get to frontal passage, there may a time frame early Tuesday evening into Wednesday morning where the winds go light and variable along with dew points in the lower to mid 70s. While we are still early on in the season, there is the potential for sea fog to develop early Tuesday evening through Wednesday morning. We are cooling the SST`s with each frontal passage and with dew points in the mid 70s along with light and variable wind flow, this could set the stage for a window of sea fog. We will continue to keep an eye on this. After the potential brief window for fog, the aforementioned front is expected to press through the Keys sometime Wednesday. This will result in winds clocking around the compass becoming north to northeasterly Wednesday night into Thursday. Accompanying the freshening winds will also be a dip in the dew points, potentially back into the mid to upper 60s along with a few degrees drop in temperatures. Moisture is expected to be remain rather meager through much of the week resulting in a dry forecast. However, rain chances will be lurking nearby, mainly over the marine area surrounding the Keys. In the wake of the front, a series of much weaker high pressure systems will traverse across the eastern United States as the pattern remains progressive. Therefore, expect breezes to continue to clock around the compass this week as multiple frontal systems approach and try to press through the Keys. Rain chances remain near nil for the Island Chain through late week before slight chances creep back in for the second half of the weekend. && .PRELIMINARY POINT TEMPS/POPS... Key West 82 75 83 73 / 10 10 10 0 Marathon 82 74 83 72 / 10 0 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