859 FXUS62 KKEY 130816 AFDKEY Area Forecast Discussion National Weather Service Key West FL 416 AM EDT Fri Sep 13 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 415 AM EDT Fri Sep 13 2024 It has been mostly quiet overnight. Weak nebulous pressure field across the Keys has been allowing winds to box around the compass at times while remaining weak. The winds came back around from the southeast and this has allowed lingering ghost boundaries to come to life with a few isolated showers. Elsewhere, across the southwestern Straits of Florida where mass is converging we have some additional very small showers. Light winds also means that conditions remain very sticky this morning with current temperatures in the mid 80s and dew points in the upper 70s. The combination of which is maintaining heat indices of 95 to 102 degrees....yuck! .FORECAST... The forecast thought process remains as stagnant as this weather pattern. Unfortunately for the Keys a weak, ill-defined area of high pressure will continue to sit across the Florida Peninsula and the Florida Keys. This will keep winds light and variable at times, which will do us no favors is keeping conditions from feeling like a sauna. To no surprise, a Heat Advisory will once again be in effect for the entire island chain for Heat Index values near 110 degrees. The weak flow also means that any boundaries that collide with enough force will be able to easily access the readily available boundary layer moisture and allow for showers to develop. That said, given the weak flow, coverage will be isolated, cloud line driven, or outflows from the mainland. As we come out of this weekend and start the next work week, a decaying frontal boundary will slide and stall near the Sunshine State. This feature could provide a better focal point for showers and thunderstorms. Model guidance has been trending upwards with rain chances next week but given the weak nature of the front and our position relative to where the next upper level forcing will be, hesitant to pull the trigger yet. Plus we have several days to watch this scenario unfold. && .MARINE... Issued at 415 AM EDT Fri Sep 13 2024 Light and at times variable breezes will continue through Tuesday across the Florida Keys coastal waters. The remnants of Tropical Depression Francine will decay inland across the Lower Mississippi Valley today, with westerly swells from Francine continuing to impact the western Keys marine zones. A decaying frontal boundary will slowly slide and potentially stall near or just north of the Florida Keys starting late Monday. This could bring higher rain and thunder chances back to the region. && .AVIATION... (06Z TAFS) Issued at 415 AM EDT Fri Sep 13 2024 VFR conditions paired with southeast to south breezes near 5 kts will continue through the morning with the direction becoming variable by the afternoon today. With precipitation chances of 30 percent today, we can't rule out some shower activity possible near the terminals. However, the lack of confidence with respect to location means we will keep VCSH out of the TAF package for now. && .CLIMATE... On this day in Keys weather history, in 1987, the record warm-low of 86F was last recorded in Marathon. This is also tied as the warmest low temperature recorded during the month of September. Climate observations for Marathon date back to June 1950. && .PRELIMINARY POINT TEMPS/POPS... Key West 92 82 92 82 / 20 20 30 30 Marathon 92 82 91 82 / 30 20 30 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Heat Advisory from 10 AM this morning to 7 PM EDT this evening for FLZ076>078. GM...None. && $$ Public/Marine/Fire...LIW Aviation/Nowcasts....DP 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