Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
889 FXUS62 KKEY 210830 AFDKEY Area Forecast Discussion National Weather Service Key West FL 430 AM EDT Tue May 21 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 430 AM EDT Tue May 21 2024 After quite a chaotic day of active weather yesterday, the upper level trough responsible for the massive rainfall totals seen across the Keys yesterday has shifted for enough eastward that the Keys are now out of the the main areas of convection. Glancing at GOES water vapor imagery, the convection is best seen to our east across the Bahamas and in the western North Atlantic. CIMSS MIMIC TPW highlights a swath of drier air nosing its way south across the forecast area this morning, but showers and thunderstorms have still been able to develop along a Florida land breeze. The strongest convection is in the distant Straits of Florida. A few island communities have seen some measurable rainfall overnight, but nothing in comparison to the totals seen yesterday. Winds have finally shifted to the north, which has helped temperatures drop into the upper 70s and kept dew points in the lower 70s. Over the next few days, the aforementioned upper-level trough will tighten and elongate itself west of the East Coast. Despite being on the less favorable (western) side of this trough, forecast soundings are depicting decent low-level moisture and adequate CAPE to support showers and thunderstorms through Wednesday. Low- level flow will generally be light and, at times, variable. This nebulous flow could help spur various mesoscale processes/interactions, such as land breezes and cloud lines, that could bring measurable rainfall to the island chain. Have kept 30% rain chances (above most MOS guidance) for now, but will continue to keep an eye on how any patches of drier air influences convective trends. Once we are finally out of the influence of the upper low by Tuesday night into Wednesday, high pressure will build back in and easterly flow will resume. There is still a slight chance (10%) of showers and thunderstorms through the extended forecast, however, the atmospheric profile will become less favorable as a drier airmass infiltrates the region. Temperatures through the weekend are forecast to be a few degrees above normal, but dew points will remain in the lower to mid 70s, keeping us below Heat Advisory levels. && .MARINE... Issued at 430 AM EDT Tue May 21 2024 There are no watches, warnings, or advisories in effect for the Florida Keys coastal waters. From synopsis, today through Wednesday, breezes will gradually shift to the east as high pressure in the western North Atlantic builds back in across the region. Gentle east to southeast breezes will resume Friday through Saturday. && .AVIATION... (06Z TAFS) Issued at 430 AM EDT Tue May 21 2024 Early morning showers (with a couple embedded thunderstorms) in the vicinity of the island chain will weaken after sunrise. From then, VFR conditions are expected at both EYW and MTH today. Near surface winds will be light and variable, becoming southeast at around 5 knots by this afternoon. && .CLIMATE... The record breaking 7.08 inches of rainfall recorded yesterday, May 20th, has boosted May 2024 into the top 10 wettest Mays on record (currently sitting at 8th wettest May). This feat was achieved despite yesterday being the only day rainfall has been recorded thus far in May 2024. && .PRELIMINARY POINT TEMPS/POPS... Key West 87 79 89 80 / 20 30 20 30 Marathon 87 79 89 81 / 20 30 30 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...NB Aviation/Nowcasts....JAM Data Acquisition.....JAM Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest