textproduct: Key West

KEY MESSAGES

- 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.

AVIATION

(18Z TAFS) Issued at 126 PM EDT Sat May 30 2026 VFR conditions will prevail at both island terminals through the TAF period, with near-nil rain and thunder chances. Near- surface winds will remain light and variable.

PREV 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.

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...None.