textproduct: Key West

KEY MESSAGES

- A cold frontal passage across the Florida Keys today will usher in a prolonged period of windy conditions along the island chain.

- A Small Craft Advisory is in effect for all coastal waters for hazardous winds and seas. These conditions will last through the next several periods.

- Shower and thunder chances will decrease during the early part of the week as a dry air mass approaches the Florida Keys.

DISCUSSION

Issued at 1022 AM EDT Sun Oct 18 2026 It's a cloudy and windy morning out there across the Keys with a cold front currently situated almost parallel to the island chain. Numerous showers and isolated thunderstorms are focused across the Hawk Channel and Florida Straits while a significantly drier airmass is slowly sinking southward across the Gulf and Florida Peninsula. Mid-level water vapor imagery shows the parent trough and developing nor'easter is rotating near the Outer Banks of the Carolinas where it will continue to strengthen over the next 24 hours. Surface and marine observations have been reporting continuous fresh to occasionally strong breezes along the island chain and surrounding nearshore waters, supporting the ongoing Small Craft Advisory. Activity near the Upper Keys will need to be monitored today as slow storm motions and backbuilding may lead to isolated flooding concerns if the activity were to become focused over land. However, activity is currently situated offshore just to the south and east of the Upper Keys, drifting towards the south/southwest. Our expectations remain the same as previously advertised, while passing showers may occasionally occur across the island chain today, the highest coverage should remain focused in the Straits while the front continues to slowly sink southward. Hopefully this means limited interruptions to outdoor activities this afternoon, at least on land. Our main concern continues to be hazardous marine conditions, particularly for smaller vessels including dinghies.

MARINE

Issued at 1022 AM EDT Sun Oct 18 2026 A Small Craft Advisory is in effect for all the Florida Keys waters.

From synopsis, a cold front is situated nearly parallel to the Florida Keys waters with fresh to strong breezes occurring across the nearshore and offshore waters. Hazardous winds and seas are expected to continue through this afternoon, and a Small Craft Advisory is in effect for all the Florida Keys waters. The cold front is expected to stall across the Straits of Florida tonight. Expect fresh to strong northeasterly breezes to prevail through the first half of the week. Shower chances will gradually decrease by Monday as drier air begins to move in while the front is forced further south.

AVIATION

(12Z TAFS) Issued at 823 AM EDT Sun Oct 18 2026 Occasional aviation impacts are expected through this TAF period due to a cold front extending across the area. Expect low ceilings to bounce from MVFR to VFR at times with prevailing VFR returning this evening. Most of the rain will focus south of the terminals during this period, but we will be watching trends to see if an AMD is needed to add a prevailing mention of SHRA or TS. Northeasterly sfc winds will remain elevated at 10-15 kts with gusts of 20-25 kts.

PRELIMINARY POINT TEMPS/POPS

Key West 86 76 86 76 / 70 50 40 20 Marathon 85 77 85 76 / 70 50 40 20

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...Small Craft Advisory until 11 PM EDT this evening for GMZ031>035- 042>044-052>055-072>075.