Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
964 FXUS62 KKEY 212007 AFDKEY Area Forecast Discussion National Weather Service Key West FL 307 PM EST Thu Nov 21 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 305 PM EST Thu Nov 21 2024 It has been a rather pleasant albeit breezy day across the Florida Keys. This is thanks to the recent cold front that passed through late last tonight. Unlike other cold front passages, we have seen a longer period of northwest to north winds. This has brought a good source of cold air advection, especially along the west coast of Florida and over mainly the Lower Keys and points west. As a result, we have seen a near constant stream of stratocu across these areas. In addition, daytime highs have been near steady in the mid 70s across the Lower and Middle Keys, while the Upper Keys, which saw more sunshine, got up into the upper 70s. Dewpoints have remain rather comfortable in the lower to mid 60s. .FORECAST... The full effects of the cold front will be felt overnight as cold air advection will continue to filter into the region. Unlike other fronts, the cold air advection will even persist into Friday and early Saturday thanks to a surface low dropping out of the Great Lakes region. Though this feature is far removed from the Florida Keys, it will maintain a large fetch of northwest to north winds all the way from the Great Lakes to the Florida Peninsula. This means surface winds will maintain a slightly west of north motion allowing for effective mixing overnight. The result will be stronger winds with speeds approaching 20 to 25 knots, especially immediately downwind of the mainland. Second, overnight lows will fall into the 60s for the Lower and Middle Keys, while possibly dipping below 60 degrees in the Upper Keys. That being said, this will be the first full night of the cold air advection may struggle to get below 60 degrees just given how relatively warm the Florida Bay is at this time. As we go into Friday and we get that second shot of cold air advection we may have a better chance of seeing sub 60 degree overnight lows in the Upper Keys. Thereafter, high pressure will slide into the North Atlantic, allowing winds to clock around to the northeast and eventually more east than northeast. This will allow for the air to slowly moderate back up as the air comes more so off the Atlantic. Daytime temperatures will return to near 80 degrees by Monday with overnight lows back well into the 70s. Dry air will remain stoutly in place such that rain chances will be near nil through the next seven days. && .MARINE... Issued at 305 PM EST Thu Nov 21 2024 Small Craft Advisories remain active in the western waters for fresh northwest breezes. Meanwhile, gentle to moderate breezes elsewhere will sharply freshen shortly after sunset, resulting in widespread Small Craft Advisory conditions. From synopsis: Fresh northwest to northerly breezes will persist across the western waters while the brief lull in the eastern waters will rapidly freshen this evening. Moderate to fresh northwest to northerly breezes will continue through the remainder of the week, with considerable diurnal speed variations. High pressure will then advance eastward through the Gulf Coast states this weekend resulting in winds relaxing and veering northeast to east northeasterly. && .AVIATION... (18Z TAFS) Issued at 305 PM EST Thu Nov 21 2024 VFR conditions will prevail at both terminals through the evening. EYW will continue to see up to BKN VFR ceilings as low level clouds continue to move southward into tonight, while MTH remains on the periphery of the cloud field with little sky coverage at best. Winds will continue to be northwest to north, with potential for crosswind issues at both terminals. Crosswind magnitudes may be higher at MTH than EYW by a few knots. && .CLIMATE... In 1914, the daily record cold high temperature of 61F was recorded in Key West. This is also tied for the coldest high temperature ever recorded in November. Temperature records date back to 1872. && .PRELIMINARY POINT TEMPS/POPS... Key West 68 77 66 75 / 0 0 0 0 Marathon 64 75 63 73 / 0 0 0 0 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Small Craft Advisory for GMZ031>035-042>044-052>055-072>075. && $$ Public/Marine/Fire...AP Aviation/Nowcasts....MC 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