textproduct: Key West

KEY MESSAGES

-Confidence is high that we will enter a quickly changing weather pattern for the upcoming week.

-A front will move through late tonight into Thursday with a brief bout of breezy conditions. Look for a secondary, potentially strong front to move through early Thursday.

DISCUSSION

Issued at 1005 PM EST Sun Jan 11 2026

Winds this evening have been light to gentle through the evening due to a fairly weak pressure field across our area that has also been perturbed by day time heating over South Florida. While this evenings sounding indicated we remain capped, the cap is up above 800 mb. This along with what best can be described as South Florida sea breeze activity affected portions of the island chain earlier this evening, but has since almost entirely dissipated. Showers do remain across the Florida Straits along the Florida convergence boundary. Mild conditions are in place with temperatures in the lower 70s with dew points in the upper 60s.

A cold front is expected to advance southward through the Keys late overnight. This front is being driven southward by a robust high sliding east southeastward through the southeastern United States. Expect winds to sharpen markedly late in the overnight in wake of the cold front. Unfortunately, this will only produce a tiny amount of cooling and drying as the responsible high will quickly push east southeastward. As a result, winds will quickly veer northeasterly and slacken tomorrow. Expect overnight lows to possibly visit the upper 60s with dew points slipping into the mid 60s. Rain potential will be slight to low chance. The Upper Keys will be most likely to be affected due to a confluence zone setting up along the Gulf Stream baroclinic boundary.

MARINE

Issued at 1005 PM EST Sun Jan 11 2026

Light to gentle broadly northerly breezes will freshen late overnight as a cold front sweeps southward through Keys waters. A Small Craft Advisory has been hoisted for all Keys waters. This wind surge is expected to be fairly short lived as a ridge axis presses quickly southeastward into the Gulf and southeast Atlantic states tipping slackening breezes northeasterly.

AVIATION

(00Z TAFS) Issued at 1005 PM EST Sun Jan 11 2026

Isolated showers currently over Florida Bay are expected to mainly stay just east of the MTH vicinity late this evening. VFR conditions are expected to prevail at the EYW and MTH terminals for much of the overnight, with the main issue increasing northerly winds from the current 4 to 7 knots to 10 to 13 knots and frequent gusts near 20 knots as a cold front moves through in the 14/11-12Z time frame. Isolated showers also accompanying and following the frontal passage Monday morning. At this time the more significant coverage in showers may be east enough of the two Keys terminals to keep vicinity showers out of the TAFS for now, however there is a chance, 40 to 55 percent, of MVFR ceilings for a few hours Monday morning at EYW around and after the frontal passage.

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...Small Craft Advisory for GMZ031>035-042>044-052>055-072>075.