Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
373 FXUS62 KKEY 060830 AFDKEY Area Forecast Discussion National Weather Service Key West FL 430 AM EDT Thu Jun 6 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 430 AM EDT Thu Jun 6 2024 Mostly clear, warm and humid conditions prevail along the Florida Keys on this early Thursday morning, with radar detecting only isolated showers in the distant Straits and the offshore Gulf waters. Temperatures are hovering in the lower to mid 80s, with dewpoints in the mid to upper 70s, and winds on land from the southeast around 5 mph. Surface analysis depicts weak high pressure over the western Atlantic, with a cold front extending from the Great Lakes southward into central Texas. Aloft, water vapor imagery shows a mid level trough moving across the Lower Mississippi Valley and the northern Gulf, with zonal flow downstream over Florida, and the subtropical ridge suppressed southward into the Caribbean Sea. The 00Z Key West sounding sampled a conditionally unstable airmass up to a weak inversion based near 600 mb, with near normal PW of 1.76 inches, although a fair amount of dry air was present in the lower and especially in the mid levels above the inversion. Today should remain mostly dry with ample sunshine, similar to the past few days, as the lack of any strong forcing combined with a rather unfavorable mesoscale regime (weak and generally difluent SE flow) and dry mid levels result in just isolated showers and storms at most. Have retained the existing 20 percent PoPs. Otherwise, high temps near 90 combined with dewpoints in the mid to upper 70s will result in max heat indices of 100-105F during the afternoon. The mid level trough initially over the northern Gulf will continue to drop slowly SE across Florida through the end of the work week and into the weekend. Meanwhile, surface high pressure will slide further offshore, as a cold front sags southward into north Florida. This will result in a somewhat more favorable large-scale environment for rainfall across our region, although the mesoscale regime will remain questionable with mostly weak S/SW flow prevailing. Have nudged PoPs up slightly for most periods from tonight through Sunday, but held mostly to low to mid chance, well below the very high NBM PoPs and close to the MOS consensus. There should be a period of lower rain chances centered on Saturday night, when a mid level ridge over the Gulf nudges eastward into our area. Forecast confidence remains quite low beginning early next week. The latest guidance generally agrees on a deepening mid latitude trough across the eastern CONUS, but continues to present a variety of solutions regarding evolution of the Central American Gyre and possible surface low development somewhere near the Yucatan Peninsula. Regardless of the details, deterministic and ensemble guidance suggest the potential for deep moisture to surge northward into our area, with the latest EC ensemble mean PW near or above 2 inches from Monday onward. As noted previously, there may be a strong moisture gradient somewhere in our region, based on where the gyre ultimately sets up. For now, have continued with above normal rain chances, expecting adjustments to the forecast during the next few days as the expected weather pattern becomes more clearly defined. && .MARINE... Issued at 430 AM EDT Thu Jun 6 2024 Late night observations show E to SE breezes easing to 5 to 10 knots along the reef and at Long Key C-MAN, with seas at Satan Shoal running around 1.5 feet. No marine headlines are currently in effect, and none are expected through the weekend. From the synopsis, weak high pressure over the western Atlantic will slide further offshore through the end of the week as a frontal boundary stalls off the Eastern Seaboard and over north Florida. This will result in gentle southeast breezes across the Keys coastal waters today, becoming light to gentle from the south to southwest from Friday through the weekend and into early next week. && .AVIATION... (06Z TAFS) Issued at 430 AM EDT Thu Jun 6 2024 VFR conditions will persist at EYW and MTH through the upcoming TAF period. Near surface winds will be east to southeast at 5 to 10 knots. Occasional showers cannot be ruled out near the island terminals, but the confidence is too low to include a VCSH group in the TAF. && .CLIMATE... On this day in Keys Weather history, in 1881 at Key West a daily record high temperature of 96F was recorded. This observations also marks the warmest temperature ever recorded in June at Key West. Temperature records at Key West date back to 1873. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...Jacobson Aviation/Nowcasts....AJP Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest