Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
376 FXUS62 KKEY 261931 AFDKEY Area Forecast Discussion National Weather Service Key West FL 231 PM EST Tue Nov 26 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 230 PM EST Tue Nov 26 2024 A weak outflow boundary late last evening from Cuba pushed northward overnight then parked itself over the Straits of Florida, modestly invigorated by a land breeze pushing off the Keys island chain. This feature has remained surprisingly in tact today. Outside of this, GOES-16 visible satellite imagery has struggled to even detect occasional fair weather cumuli across the entire forecast area. Boundary layer veering sampled in this morning`s 12z sounding at KEY supports the slightly nudged up dew points and temperatures today relative to the past couple of days. Given higher than normal confidence in the synoptic pattern over the next seven days, virtually negligible changes were made to the inherited overnight forecast package for this iteration. The surface high that has dominated the sensible weather over the past several days will slowly weaken, resulting in slowly waning pressure gradient. Forecast soundings highlight scant moisture through the end of the week, and a dry Thanksgiving forecast appears virtually a slam dunk for the Florida Keys. Despite decent veering (warm advection) expected, the northeast to east surface flow coupled with Bayside and Gulfside waters lurking in the mid 70s will keep high temperatures only at near normal through the end of the week. Global ensemble numerical weather prediction guidance is in great agreement that a shortwave trough originating over northwestern Canada will dive southward across much of the country. This will push a progressively weakening air mass boundary through the Keys Friday night. Dew points and temperatures look to only nudge down a degree or two in the wake of this boundary. A quasistationary area of low pressure over Ontario should pivot a stronger shortwave trough and associated cold front through the Keys late in the weekend. Strong, continental high pressure will build in the wake of this feature, promoting breezy conditions and a bout of cooler weather for early next week. Rain chances throughout the next seven days will be limited to a brief, light shower associated with each frontal pass over the weekend, or in the freshened northeasterly breezes early next week. Given these scenarios and limited moisture expected up to the 850 mb isobaric surface, dime PoPs seems appropriate for Friday night and beyond. && .MARINE... Issued at 230 PM EST Tue Nov 26 2024 No watches, warnings, or advisories are currently in effect for the coastal waters of the Florida Keys. From synopsis, as a surface high pressure system lingering over the Florida Peninsula continues to weaken, moderate northeast to east breezes will gradually slacken through Friday. A weak frontal boundary will push through the Keys coastal waters Friday night, with limited impacts to winds and seas. A second, stronger cold front will blast through the Keys late Sunday or Sunday night, with freshened breezes and building seas expected in its wake. && .AVIATION... (18Z TAFS) Issued at 230 PM EST Tue Nov 26 2024 VFR conditions will prevail at the EYW and MTH terminals through the TAF period, with rain chances near zero, and northeasterly surface winds near 10 knots. && .PRELIMINARY POINT TEMPS/POPS... Key West 78 71 79 73 / 10 10 0 0 Marathon 78 71 79 72 / 10 10 10 10 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...BT Aviation/Nowcasts....DP Data Acquisition.....MC Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest