Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
391 FXUS62 KKEY 220232 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1032 PM EDT Sat Sep 21 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 1030 PM EDT Sat Sep 21 2024 The main item of interest this evening has been an outflow boundary moving west to southwest near 10 knots throughout the Florida Keys. Occasionally, isolated showers and thunderstorms wax and wane along this boundary. One of these grew intense enough to the southeast of Marathon to warrant a Special Marine Warning earlier this evening. For the most part though, these have mostly remained light to moderate showers. This boundary is currently draped from north to south across the offshore Gulf waters through the Lower Keys to the nearshore and offshore waters to the south. Otherwise, it has been a rather quiet late September evening with temperatures along the Island Chain in the lower 80s and dew points in the mid 70s. Weak surface high pressure is slowly traversing across the Southeastern U.S. resulting in northeast to east breezes of 5 to 10 knots at marine platforms throughout the Keys. Island Chain communities are observing generally light and variable winds. .SHORT TERM FORECAST... The 00z sounding this evening showed once again a mostly dry profile with some moisture in the low levels up to around 800 mb. The PWAT value measured was 1.69 inches which very similar to last evening and close to the median for the date. CAPE is also still quite high around 2230 J/kg slightly less than yesterday evening. Therefore, we have the trigger in the form of the outflow boundary and instability but are lacking the moisture again tonight. Therefore, no changes needed to the ongoing forecast. && .MARINE... Issued at 1030 PM EDT Sat Sep 21 2024 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, as a trough continues to slide eastward across the western North Atlantic through the rest of the weekend and into early next week, high pressure building along the Eastern Seaboard will bring gradually increasing easterly breezes to the Keys coastal waters beginning on Monday. Heading into the middle of next week, the forecast will depend on the potential development and movement of low pressure over the northwestern Caribbean Sea. At this time, we expect freshening east to southeast breezes, with the strongest winds over western sections of the Keys waters. .COASTAL FLOOD... A Coastal Flood Advisory remains in effect for the Upper Keys, and a Coastal Flood Statement remains in effect for the Middle and Lower Keys, as above normal tides continue. Boaters can expect less clearance under fixed bridges, especially during the hours around high tide. && .AVIATION... (00Z TAFS) Issued at 1030 PM EDT Sat Sep 21 2024 VFR conditions are expected for EYW and MTH terminals through the overnight and into the morning hours on Sunday. Near surface winds will be northeast to east between 5 to 10 knots. && .PRELIMINARY POINT TEMPS/POPS... Key West 90 82 90 81 / 20 20 20 30 Marathon 90 81 89 81 / 20 20 20 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 5 PM EDT Monday for FLZ076. GM...None. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....MJV Data Acquisition.....DR Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest