textproduct: Key West

KEY MESSAGES

- A Small Craft Advisory is in effect for all Keys Coastal Waters

- Very warm and humid conditions over the next few days will lead to bouts of major risk of heat illness in the afternoon hours, with little relief during the overnight periods.

- Quick moving showers and storms may bring bursts of moderate to heavy rainfall, reduced visibility, and gusty winds through Tuesday. - A general 2-4" of rainfall and thunderstorms, with locally higher amounts, are possible at most island communities Wednesday through next Sunday.

DISCUSSION

Issued at 1010 PM EDT Mon May 25 2026 Warm and humid conditions continued across the Florida Keys this Memorial Day. Dew points across the island chain, once again, were in the lower to mid 70s. Temperatures across the island chain were in the 80s. Occasional periods of showers were able to transit across the Keys. However, as of the evening hours, shower activity has diminished per KBYX radar returns. The 00Z KKEY sounding provided some information as to why. Sampled precipitable water dropped by over 0.4" compared to last night. CAPE values were about 1000 J/kg lower than yesterday. The measured wind field showed southeasterly winds persisting from the surface to about 26 kft, while yesterday's winds backed northeasterly by 13 kft. These observations suggest a dry slot has moved over the Florida Keys. GOES East water vapor imagery highlights the extent of this drier layer, stretching from over the Upper Keys into the Bahamas. The center of this dry circulation appears to be near 30 N and 70W, north of Hispaniola and east of Georgia. This would be the center of a broad upper level ridge.

What does this imply for tonight's weather? Expect breezy conditions to continue through the overnight hours. Small Craft Advisory conditions continue for the Keys waters, after all. Showers that form are likely to be short lived, fast moving, and capable of moderate to heavy rainfall. Even though the atmosphere is drier than the past few days, a significant amount of moisture remains near the surface.

GOES East satellite data also highlights the feature on track to bring dry weather to an end this week. A shortwave trough is slowly making its way east along the northern Gulf Coast. Heavy showers are seen in satellite imagery over the Central Gulf. The first signs of this feature nearing the Keys are likely to be high altitude cirrus clouds streaming in from the south southwest. We are swiftly approaching the wet season in the Florida Keys.

MARINE

Issued at 1010 PM EDT Mon May 25 2026 A Small Craft Advisory is in effect for the coastal waters of the Florida Keys. From synopsis, an Atlantic high pressure system centered near Bermuda will support fresh east to southeast breezes through Tuesday night. Breezes will noticeably slacken and veer to the southeast to south as the high slides eastward and weakens by the middle of the week. Shower and thunderstorm chances will increase for the middle and latter part of the work week.

AVIATION

(00Z TAFS) Issued at 1010 PM EDT Mon May 25 2026 VFR conditions will prevail at EYW and MTH for the upcoming TAF period. Near surface winds will continue to be slightly raised during overnight hours and a bit weaker during the day. Isolated showers will continue to percolate near, but not in the vicinity, of the terminals.

PRELIMINARY POINT TEMPS/POPS

Key West 81 90 81 90 / 30 20 40 50 Marathon 80 87 80 87 / 20 20 40 50

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...Small Craft Advisory until 5 AM EDT Tuesday for GMZ031>035- 042>044-052>055-072>075.