Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
794 FXUS62 KKEY 180845 AFDKEY Area Forecast Discussion National Weather Service Key West FL 445 AM EDT Sat May 18 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 445 AM EDT Sat May 18 2024 It`s yet another unseasonably warm morning in the Florida Keys. Current temperatures across the island chain are in the lower to mid 80s and dewpoints close behind with values near 80. KBYX is once again clear of any precipitable echoes as mean layer ridging is suppressing convective development across South Florida and the Western Caribbean. Cloud cover is generally confined to isolated patches of shallow cumulus in the Straits of Florida. As our synoptic pattern remains relatively unchanged from yesterday, we are expecting another hot day today. Usually, this would be a good time to look for developing thunderstorms but weakening southerly breezes due to mainland heating and a fairly dry mid to upper level atmosphere will choke out any possible showers. Unfortunately, this has little effect on our low level moisture meaning that dewpoints will continue to be in the upper 70s today. As a result, a Heat Advisory will be in effect from 10 AM this morning until later this evening as heat index values are forecast to reach up to 110 degrees. Tonight will also be a repeat of previous nights with breezes freshening with the cooling of South Florida`s temperatures and low temperatures in the lower to mid 80s. Sunday will also be another hot day across the Keys, only this time some of our synoptic puzzle pieces will start to shift. Sunday night into Monday, the deep layer ridging will shift east towards the Atlantic as a mid latitude trough settles on the ridge`s northeast periphery and slides into the Gulf of Mexico from the Midwest. Guidance continues to be consistently conflicted on how much low level moisture will be available with this trough`s approach. Opted to hold chance PoPs and slight chance thunder from Sunday night into Tuesday. Temperatures should start to return near normal at the start of the week as well with breezes shifting to the north. There`s still a chance that this will advect some lower dewpoints into our area in the middle of the week, but the signal is certainly not as strong as it was a few days ago. Stay tuned. && .MARINE... Issued at 445 AM EDT Sat May 18 2024 Currently no watches, warnings, or advisories are in effect for the Florida Keys coastal waters. From synopsis, the western extent of a low-level ridge axis extends west-northwest through the Bahamas and across the Keys. Southeast breezes will tend to peak and lull overnight through Sunday as the heating and cooling of South Florida and Cuba modulate the local wind forecast. There may be a break in the rain-free conditions Sunday night through Tuesday, followed by variable breezes Tuesday through Wednesday. && .AVIATION... (06Z TAFS) Issued at 445 AM EDT Sat May 18 2024 VFR conditions are expected through tomorrow morning at EYW and MTH. Surface winds will oscillate between south southeast and east southeast over the course of the TAF period, remaining between 6 to 12 knots. && .CLIMATE... On this day in 1994, the daily record rainfall of 2.52" was recorded in Marathon. Rainfall records date back to 1950. && .PRELIMINARY POINT TEMPS/POPS... Key West 92 82 92 79 / 0 10 20 30 Marathon 91 83 91 80 / 10 10 20 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Heat Advisory from 10 AM this morning to 6 PM EDT this evening for FLZ076>078. GM...None. && $$ Public/Marine/Fire...JAM Aviation/Nowcasts....NB Data Acquisition.....NB Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest