Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
419 FXUS62 KKEY 050327 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1027 PM EST Thu Dec 4 2025 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... -Northeast to easterly breezes expected to peak at light to moderate overnight. -Near nil rain chances through the first half of the weekend. -Breezes veering southeasterly and then southwesterly on Sunday -Moisture increasing Sunday and Monday ahead of a possible frontal system early next week. && .DISCUSSION... Issued at 1025 PM EST Thu Dec 4 2025 Another warm and humid evening is ongoing across the Florida Keys as each day so far for December has averaged above normal. Temperatures along the Island Chain are in the mid 70s and dew points are in the lower 70s. For perspective, the average low for Key West is typically around 70 degrees and average daytime highs are typically in the upper 70s. High pressure remains immersed off the Southeast U.S. coastline. This is promoting northeast to east breezes between 10 and 15 knots at marine platforms surrounding the Island Chain. Since high pressure is reigning supreme, moisture is rather lackluster. This has led to KBYX radar not detecting any shower activity through the remainder of the afternoon and through the evening hours. GOES 19 Nighttime Microphysics shows most of the clouds across the marine area south of the Island Chain with some high level cirrus clouds streaming from west to east. This is leading to a partly cloudy sky this evening. .SHORT TERM FORECAST... The 00z evening sounding shows a mostly dry profile once again. However, there are two subtle differences compared to the sounding last evening. Lower level moisture has increased in the layer between 950 to 900 mb as well as 250 to 200 mb. This can be attributed to the low and high level clouds we are seeing on the GOES 19 Nighttime Microphysics imagery. The PWAT value measured was 1.24 inches which is right near the median for the date. The wind profile is becoming a little more favorable for showers with the 1000 ft AGL wind being due to east and then the 3000 ft AGL being southeast to south. However, the wind direction change is a little more than we would like to see, but it is starting to trend towards a more favorable setup. Therefore, no changes are expected to the ongoing dry forecast. The only potential catalyst for a shower would be any mesoscale processes, or directional or speed convergence and this most likely would occur over the southern distant Straits and not far from the northern Cuba coastline. && .MARINE... Issued at 1025 PM EST Thu Dec 4 2025 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, gentle to moderate northeast to east breezes will begin to veer southeasterly overnight. A messy high pressure system over the eastern CONUS will allow breezes to slacken to light to gentle over the weekend. Shower coverage will start to increase by the start of next week as breezes become southerly, and a cold frontal passage is possible early next week. && .AVIATION... (00Z TAFS) Issued at 1025 PM EST Thu Dec 4 2025 VFR conditions are expected to persist through the TAF period. Nil rain chances continue as dry air remains entrenched across the Keys. Near surface winds remain northeast to east between 4 to 8 knots with winds becoming more east to southeast early Friday and then eventually southeasterly Friday afternoon. && .PRELIMINARY POINT TEMPS/POPS... Key West 81 73 83 73 / 0 0 0 10 Marathon 80 74 81 74 / 0 10 0 10 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....MJV Data Acquisition.....DP Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest