textproduct: Key West

KEY MESSAGES

- A Coastal Flood Statement remains in effect. Low lying areas will see minor saltwater ponding around the times of high tide.

- A weak front will stall near or just south of the Florida Keys tomorrow morning. This will lead to low to medium chances for showers and thunderstorms over the next few days.

DISCUSSION

Issued at 146 PM EDT Mon Oct 12 2026 So far today there has been minimal precipitation across our waters despite a frontal boundary evident on vis satellite and surface analysis extending from northeast to southwest across South Florida. CIMSS steering products indicate that ridging remains centered over the northern Gulf while Atlantic ridging extends across the Bahamas. Mid-upper level troughing extends south along the Florida Peninsula, promoting modest height falls (as noted on the 12Z RAOB) despite the overwhelming anti-cyclonic presence nearby. Nonetheless, it appears that subsidence from the surrounding regions of high pressure is winning the battle today as upper-level troughing and weak surface convergence have not been enough to produce much activity. In fact, minimal development is noted along the front beyond our waters. Also, MIMIC-TPW imagery shows the column of moisture ahead of the trough/surface front is becoming pinched in between a broad region of dry air advecting west across the Bahamas and the region of post- frontal dry air advecting south, so favorable moisture content is decreasing. Given the close proximity of the stalling front and associated thin moisture axis near or just north of the Florida Keys, it's difficult to not mention at least a chance of showers/storms through tonight. Additionally, the latest hi-res guidance continues to show some potential for mainland convection to track towards the Keys this evening. As far as tides and coastal flooding is concerned, tidal anomalies are very slowly decreasing, but overnight high tides continue to peak near Coastal Flood Statement criteria, so the Statement will remain in effect for the Florida Keys through at least tonight.

The diffuse frontal boundary will stall near or south of the island chain tomorrow morning with a sharp gradient of drier air expected to situate north of the Keys. This will continue to promote gentle to moderate northeasterly breezes across our coastal waters while 30- 40% PoPs become focused across the Straits of Florida. By midweek, the region of high-pressure over the Southeast will begin to shift towards the Western Atlantic. This will promote deep-southeasterly flow across the Florida Keys and should allow deeper moisture to return. Persistent gentle to moderate northeast to easterly breezes will continue during this time. By the end of the week, global models suggest the mid/upper-level ridge will be fully centered south of Bermuda while longwave troughing deepens across the Central to Eastern CONUS. Recent model runs have begun to resolve a stronger subtropical ridge which means the prospects of a strong frontal passage across the Keys this weekend has decreased. This evolution still bears watching over the coming days, but current solutions stall a cold front across the northern Gulf, focusing the higher winds north of our waters. Another feature to watch is an easterly wave currently in the Caribbean Sea. This feature may meander towards the Yucatan this week, potentially becoming more influential to our perceivable weather by the weekend.

MARINE

Issued at 146 PM EDT Mon Oct 12 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. Despite a cold front to our north, precipitation has been minimal so far today.

From synopsis, a couple of nearby features will define the weather across the Florida Keys for the first half of the week. The Atlantic Ridge is gradually weakening and retreating east towards the central Atlantic. Another region of high pressure is located over the Southeast and northern Gulf. Between the two high pressure centers lies a weak frontal boundary that is extending across south Florida. The front is forecast to slowly pass across the Keys waters by tomorrow. This will promote gentle to moderate northeast to east breezes. There will be slight chances for showers and a few thunderstorms over the next few days as the diffuse and weakening front stalls near the Straits of Florida. Late in the week, a strong cold front could develop and move towards the Florida Keys. Currently, there are low chances that the front will make it to the Florida Keys waters. We will continue monitoring this potential system.

AVIATION

(18Z TAFS) Issued at 146 PM EDT Mon Oct 12 2026 VFR conditions and mostly sunny skies continue to prevail across the TAF sites this afternoon. A weak cold front is situated just to the north of the Island Chain, but convection has been minimal so far today. Hi-res guidance indicates potential mainland convection this evening which could track towards the TAF sites after 00Z. Will maintain VCSH for now, but confidence is generally on the lower end. Otherwise, expect continued 5-10 kt northeasterly winds.

CLIMATE

On this day in 2023, the daily record warm low temperature of 85F was recorded in Key West. This is also the warmest low temperature ever recorded during the month of October. Temperature records for Key West date back to 1872. Also, on this day in 2023, the daily record warm low temperature of 84F was recorded in Marathon. This is also tied for the warmest low temperature ever recorded during the month of October for the Marathon area. Temperature records for Marathon date back to 1951.

OF NOTE In 1987, Tropical Storm Floyd intensified into a Category 1 Hurricane as it moved east northeast between Cuba and the Keys. It traveled along the length of the Keys causing only minimal damage (with the exception of an F1 tornado near Rock Harbor on the 11th), with the eye passing directly over Key West bringing about an hour of "total calm" to the city.

PRELIMINARY POINT TEMPS/POPS

Key West 89 80 87 79 / 20 40 20 20 Marathon 89 80 87 79 / 20 40 20 20

KEY WATCHES/WARNINGS/ADVISORIES

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