Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
427 FXUS62 KKEY 180916 AFDKEY Area Forecast Discussion National Weather Service Key West FL 416 AM EST Tue Nov 18 2025 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... -Northeasterly breezes freshening from gentle to moderate heading into Wednesday, which will allow temperatures to return to normal values. -Deep layers of dry air continue to inhibit shower development through the work week. -Thick cloud cover from a weak low pressure system south of Cuba slowly dissipating during the day && .DISCUSSION... Issued at 415 AM EST Tue Nov 18 2025 Dry season across the Florida Keys is in full swing; however, there are a couple of interesting features. A weak disturbance south of Cuba is rather perplexing. Mid level water vapor scans from GOES East show a deep layer of dry air over most of Cuba, except a couple pulses of convection. Infrared scans are able to identify the low cloud layer around FL070 to FL 080, which was observed by last night`s sounding and the overcast layer observed by celiometers are both EYW and MTH. Individuals across the Keys will notice another impact of this cloud layer: warmer temperatures. In contrast to last night`s drop into the lower 60s (mid 50s at Big Pine Key), temperatures remain near 70. Dew points are hovering in the upper 60s, so expect another muggy morning with objects drenched in dew. Today, expect gentle to moderate breezes across the Keys with temperatures returning to near normal values. .FORECAST... GOES East water vapor imagery highlights a broad mid level ridge stretching from the Yucatan Peninsula to Arkansas. That ridge is responsible for sustaining deep layers of dry air across the Florida Keys, and that pattern is not forecast to change during the upcoming week. Breezes will be a bit more dynamic. A high pressure system, presently over the Carolinas, is progged to move into the Atlantic and build towards the Florida Peninsula by midweek. A sharper pressure gradient means moderate breezes for many of the waters around the Keys, so the chance of radiational cooling is low. Weekend weather looks more uncertain. Current numerical model runs show low pressure systems developing over the southeastern CONUS and forcing a cold front into the Gulf. This does not appear to be a strong frontal system, but it would disrupt the pressure gradient and result in light to gentle breezes. Overall, the weather pattern will be more interesting in other parts of the country instead of the Florida Keys. && .MARINE... Issued at 415 AM EST Tue Nov 18 2025 No watches, warnings, or advisories are in effect for the Florida Keys coastal waters. From synopsis, high pressure located over the eastern CONUS will slowly move into the western Atlantic today and tonight. The high will slowly build and support freshening northeast to east breezes during the work week. Moderate to fresh breezes are possible south of the island chain. Late in the week, a low pressure system traversing the southeastern CONUS may allow breezes to slacken to light to gentle. && .AVIATION... (06Z TAFS) Issued at 415 AM EST Tue Nov 18 2025 VFR conditions will prevail at the island terminals today. A swath of low MVFR, possibly IFR, based stratus is not far off and it cannot be completely ruled out that this deck will remain outside the aerodromes. Expect light, predominantly north to northeasterly breezes early this morning, transitioning gentle northeast to easterly after sunup. && .PRELIMINARY POINT TEMPS/POPS... Key West 80 73 81 72 / 10 10 0 0 Marathon 79 73 79 72 / 10 0 0 0 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...AJP Aviation/Nowcasts....11 Data Acquisition.....11 Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest