Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
748 FXUS62 KKEY 171758 AFDKEY Area Forecast Discussion National Weather Service Key West FL 158 PM EDT Fri May 17 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 1232 PM EDT Fri May 17 2024 It has been another hot, humid, and rain-free afternoon across the Florida Keys. Temperatures reached the lower 90s with a few readings in the mid 90s. Dewpoints fluctuated between 75 and 80, lending to heat indices in the 100s. South Florida, Cuba, and the Yucatan are suppressed beneath the deep, mean-layer ridging. The KBYX radar is echo free and skies are mostly sunny. .FORECAST... The mean-layer ridge centered over the Western Caribbean will remain in control of the sensible weather tonight through Sunday. Southeasterly breezes will peak and lull as the heating and cooling of South Florida/Cuba modify the low-level gradient. The pattern will continue to support record breaking heat, and a Heat Advisory may be required on Saturday and Sunday. The mid to upper-level low currently pressing into Texas will round the northeastern flank of the mean-layer ridge Sunday night and Monday. Low-level flow will become confluent and southwesterly, while the southern flank of weakly cyclonic SFC flow will brush into South Florida and the Keys. There are mixed signals for the degree of low-level moisture in the Sunday night through Tuesday time frame. The source region is the western Gulf of Mexico, where GOES TPW suggests values greater than 2.0" are lurking. The NBM/Euro MOS guidance is wetter than than the GFS MOS, and our forecast for 30/40% rain chances is leaning on the higher end of the blend. In the back of our mind, we may be forgetting last year, never forecast rain in a drought. Low forecast confidence continues into the extended. The previously mentioned mid to upper-level low will undergo an anticyclonic wave break and setup camp either near the Greater Antilles, or north of the Bahamas, Tuesday through Thursday. Rain chances look to trend down off the early week chances, temperatures will hover near normal, but the degree of dewpoint depression is up in the air. Run-to-run consistency is strong in both camps, but model-to-model consistency is poor. && .MARINE... Issued at 1232 PM EDT Fri May 17 2024 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 tonight 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... (15Z TAFS) Issued at 1232 PM EDT Fri May 17 2024 VFR conditions are expected through the evening and overnight hours. Surface winds are forecast to range from 6 to 11 knots, with a prevailing direction of southeast to south through this evening, becoming more southeasterly overnight. Winds become more southeast to south again heading into the early morning hours Saturday. && .CLIMATE... On this day in 2012, the daily record rainfall was recorded at both Key West (2.66") and Marathon (1.49"). Rainfall records date back to 1871 in Key West and 1950 in Marathon. && .PRELIMINARY POINT TEMPS/POPS... Key West 82 92 82 92 / 0 10 10 20 Marathon 83 91 82 91 / 0 10 10 20 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Heat Advisory until 6 PM EDT this evening for FLZ076>078. GM...None. && $$ Public/Marine/Fire...CLR Aviation/Nowcasts....MJV Data Acquisition.....MJV Climate..............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