textproduct: Key West

KEY MESSAGES

- Colder and windy conditions return to the Island Chain and surrounding coastal waters following a frontal passage from earlier this afternoon. - A Small Craft Advisory is in effect for all Florida Keys coastal waters.

- Overnight lows tonight across the Upper Keys are expected to be in the mid to upper 40s, with 50 to 55 degrees for the Middle and Lower Keys. Daytime highs Friday are only expected to reach the mid 60s.

DISCUSSION

Issued at 1045 PM EST Thu Feb 5 2026 A post-frontal environment has descended upon the Florida Keys this evening. Unlike the previous front, the peak of our northwesterly winds seems to have already passed as fresh to occasionally strong breezes are currently recorded along the Reef. This is partly due to this being a weaker front and also due to winds quickly turning more northerly with drainage from mainland being introduced. KBYX radar is unsurprisingly clear of precipitable echoes as all observed precipitation over land for the day occurred in the early afternoon hours. Meanwhile, temperatures now vary greatly across the island chain with the lower 60s in the Lower Keys and mid 50s over the Upper Keys. This is pretty substantial jump from highs in the lower 70s early today with a nearly 20 degree difference observed at Key Largo.

The short term forecast is dominated by the aftermath of this reinforcing front. While breezes have declined a good deal from their peak, hazardous marine conditions will continue into tomorrow. Our KKEY 00z balloon sounding from this evening notes an extremely dry pocket of air above 850 mb with strongly backing flow in the low levels. Not only will this flow be able to mix down overnight creating some gusty pockets among the wind field, but it also signals cold air advection with low temperatures forecast to hit the upper 40s in the Upper Keys and lower to mid 50s elsewhere early Friday morning. Breezes will continue to fall off tomorrow as the surface low associated with this frontal system rockets into the North Atlantic leaving high pressure centered about the western Gulf to take over. What results is a dry and cool but warming weekend with near normal conditions expected to take over at the start of the next work week.

MARINE

Issued at 1045 PM EST Thu Feb 5 2026 A Small Craft Advisory is in effect for all coastal waters of the Florida Keys. From synopsis, fresh to strong breezes will continue through Friday morning in the wake of a strong cold frontal passage. As the front continues to push away from the Florida Keys on Friday, breezes will somewhat slacken, although marine conditions will remain hazardous. An area of high pressure will build across the Mid- Atlantic over the weekend, supporting moderate northwest breezes. As the high slides southeastward late Sunday through early next week, breezes will slacken and clock around to the northeast.

AVIATION

(00Z TAFS) Issued at 1045 PM EST Thu Feb 5 2026 VFR and dry conditions will prevail at both EYW and MTH tonight. While frequent northwest to northerly gusts to 20 to 25 knots may cause some crosswind concerns early on, breezes will slacken gradually into tomorrow morning.

KEY WATCHES/WARNINGS/ADVISORIES

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