Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
033 FXUS62 KKEY 060326 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1026 PM EST Fri Dec 5 2025 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... -Mainly light to gentle southeast breezes expected through the weekend. -Near nil rain chances through the first half of the weekend. -Moisture increases Saturday night through Monday ahead of a possible frontal system early next week. -Humidity will also continue to rise with dew points reaching potentially the upper 70s for Sunday. && .DISCUSSION... Issued at 1025 PM EST Fri Dec 5 2025 A very warm and humid evening is ongoing across the Florida Keys. Temperatures along the Island Chain are still in the upper 70s at this hour and dew points are in the lower 70s. However, due to light winds, some radiational cooling has taken place with the Big Pine Key RAWS dropping to 69 degrees a little before 10 pm EST. Surface low pressure continues to organize and strengthen off the North Carolina Coast. An elongated and weak high pressure remains to its south with the western periphery of this ridge extending into the Keys. This is promoting mainly southeast breezes of 5 to 10 knots at marine platforms surrounding the Island Chain. Moisture continues to remain meager as KBYX radar has not detected any shower activity through the remainder of the afternoon and now through the evening hours. GOES 19 Nighttime Microphysics has been detecting mainly low level cumulus clouds throughout the Keys giving way to a partly cloudy sky. .SHORT TERM FORECAST... The 00z evening sounding shows a mostly dry profile once again when compared to 24 hours ago. However, there are some noticeable differences. Moisture continues to grow in the low levels between 950 and 900 mb. This correlates well with what we are seeing on satellite and where the cloud heights have been. The wind profile remains southeast to south from 1000 to 3000 ft AGL. Another notable change has been the instability for CAPE has also been increasing from where it was yesterday. The radiosonde launched this evening measured a CAPE value of close to 800 J/kg. The PWAT value measured came in slightly lower than last evening at 1.16 inches which is a little below the median for the date. GOES 19 Total Precipitable Water (TPW) products shows PWAT values estimated to be between 0.85 inches to 1.2 inches. Therefore, no changes expected to the ongoing forecast. Like last night, if there is any shower activity, it most likely will be across the marine area south of the Chain and mostly due to directional or speed convergence and other mesoscale processes. && .MARINE... Issued at 1025 PM EST Fri Dec 5 2025 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, a low pressure system developing off the North Carolina Coast will move northeast while strengthening while a weak and elongated high pressure system remains to its south through the weekend. This will promote mainly light to gentle southeast breezes, occasionally variable. Thereafter, a developing weather system will move out of the Central Plains and into the Southeast U.S. by Sunday evening. The attendent cold front will sweep through Monday night with a brief period of moderate to fresh breezes. Shower coverage will steadily increase starting Saturday evening and continuing into early next week. && .AVIATION... (00Z TAFS) Issued at 1025 PM EST Fri Dec 5 2025 VFR conditions are expected to persist through the TAF period. Nil rain chances are expected to continue through the overnight into Saturday morning. Latest hi res model guidance is hinting at a stray shower or two developing towards the early to mid afternoon Saturday that potentially could affect either terminal briefly. However, this is very low confidence but worth the mention. Otherwise, near surface winds will remain east to southeasterly between 4 to 9 knots. && .PRELIMINARY POINT TEMPS/POPS... Key West 83 74 83 74 / 10 10 10 20 Marathon 82 74 82 75 / 10 10 10 20 && .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