Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
490 FXUS62 KKEY 300954 AFDKEY Area Forecast Discussion National Weather Service Key West FL 554 AM EDT Sat May 30 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... - Conditions may favor cloudline development this afternoon as breezes will be light to gentle out of the southwest at times. - Rain and thunder chances will only be slight (10% to 20%) through the rest of the weekend. - While highs will be seasonably warm in the upper 80s through next week, lows will remain warmer than normal, providing little relief from the heat in the overnight hours. && .DISCUSSION... Issued at 550 AM EDT Sat May 30 2026 Multiple bouts of showery weather was seen across the forecast area during the overnight hours. The KKEY sounding from last night calculated a PWAT value of 2.05" which falls in line with widespread satellite derived values near two inches. Multiple ghost boundaries across the area served as the main trigger for these showers, but once again most of the measurable rain fell across the Upper Keys. MRMS suggests the highest rainfall totals were near Tavernier with 1 to 1.5 inches, but outside of this localized area were totals of up to half of an inch. This speaks to the isolated nature of the rainfall we can manage to get, and why this pattern seems to be difficult to predict. It`s easy to say that it will rain somewhere within our forecast area, it`s more difficult to pinpoint where it will rain. Our KBYX radar is still detecting a few ghost boundaries in the area, and virtually any of them can trigger shower development. Based on radar trends, and the lack of significant lift across the area, were opting to keep rain and thunder chances just below climo for now. Another consideration is potential reverse cloudline development in the afternoon. Low level wind forecasts remain light and variable, but there does seem to be an opportunity for a window of southwesterlies around lunch time. If a cloudline can develop, then this would favor rainfall chances, but that is hard to forecast when our wind field is currently so variable and nebulous. This low uncertainty forecast continues over the next few days as high pressure across the area remains in place. A moist air mass is in place with PWAT values near 2 inches, which is close to the 90th percentile. The past few soundings from KKEY have shown that this moisture is distributed through most of the vertical column, with the exception of a couple of areas of drier air in the mid levels, so any small scale trigger should be able to get some shower activity going. Global guidance and ensembles continue to show a trough digging down the Eastern Seaboard sometime next week, possibly Tuesday and Wednesday. This will bring better lift to the general area, even though some drier air may sneak in along the vertical profile. && .MARINE... Issued at 550 AM EDT Sat May 30 2026 There are no watches, warnings, or advisories in effect for the Florida Keys local waters. From synopsis, weak high pressure across the area will support light to gentle southeast to south breezes over the next few days, becoming light and variable at times. The nebulous pressure pattern will continue through much of early next week, with near normal rain and thunder chances also expected. A weak frontal boundary may stall near the Keys coastal waters by mid week, supporting an uptick in wind speeds as well as rain chances. && .AVIATION... (06Z TAFS) Issued at 550 AM EDT Sat May 30 2026 VFR conditions will prevail at both island terminals with SCT clouds near FL020. AN OVC deck will sit near FL150, but no consequences are expected from this. There are low chances, near 20 percent, for showers during the TAF period. The most likely window of time for showers will be between 15Z and 21Z. Significant impacts arent expected in general, but amendments will be made if warranted due to isolated stronger showers. Surface winds will be variable near 5 knots, except in the vicinity of showers and thunderstorms where gusts can be stronger and erratic. && .OF NOTE IN KEYS WEATHER HISTORY... On this day in 1999, a waterspout moved onshore as an F0 tornado along the north end of Duval street. There was no damage reported. && .PRELIMINARY POINT TEMPS/POPS... Key West 88 81 89 81 / 20 10 20 10 Marathon 87 81 87 81 / 20 10 20 10 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...DP Aviation/Nowcasts....DP Data Acquisition.....DR Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest