textproduct: Key West

KEY MESSAGES

- Fog will be possible this evening across portions of the Keys due to high dew points and light breezes clocking northwest to north. - A strong high pressure system sinking into the northern Plains from Canada is forecast to freshen breezes early next week. Breezy conditions are possible at times. - A moderate drought continues for the entire island chain. Burn bans are possible, trees and bushes begin browning, and water supply decreases. For the upcoming week, there will be a slight chance for showers.

DISCUSSION

Issued at 1113 AM EST Sat Feb 28 2026

It's a warm and moist start to the weekend here in the Florida Keys! While KBYX radar is free of perceptible echoes in our CWA, a small cluster of showers (that were thunderstorms) is detected a little over 50 miles west northwest of the north edge of our offshore Gulf waters. The major story of the day is seen on GOES-19 visible satellite imagery. While mid to high level clouds quickly stream to the east over our area, some streaks of lower level stratocu meander over the island chain from the south. Meanwhile, ripples of patchy fog drifting south from the west coast of Florida are observed advecting into the northern portion of our southeast Gulf waters. While the patches are not as thick as a few hours ago, there is still a mass of fog looming north of our waters. Generally south light to gentle breezes persist along the Reef with light to calm conditions north of the island chain. Current temperatures range from the upper 70s to lower 80s with most dew points in the lower to mid 70s.

The big forecast challenge for the day is fog. Sea surface temperatures (SSTs) near or just below 70F along with dew points in the lower 70s are sustaining the fog bank off of Florida's west coastline. A surface trough pushing east through the Gulf will shove the surface ridge nosed over south Florida out into the western North Atlantic today resulting in our southerly breezes becoming light and variable and then northwest to north late. As winds shift to the north, there looks to be thermodynamic support for fog and low ceilings to advect into our Gulf waters and possibly over the Lower and Middle Keys later this afternoon and into the evening. The nature of this forecast is uncertain as it depends on the timing of the northerly wind shift as well as the maintenance of our Gulf SSTs and ambient dew points. Rain chances, however, continue to be near nil with a lack of forcing along with some dry air remaining in the mid levels. Temperatures will be remain just above normal in the short term with highs topping out in the lower 80s and lows near 70.

PREV DISCUSSION

Issued at 430 AM EST Sat Feb 28 2026

Light to gentle southeast to southerly breezes are being driven by the western end of an Atlantic ridge stretching across South Florida and the Keys. This flow has brought in a warm and moisture rich airmass. Temperatures remain in the mid 70s with dew points in the lower 70s. While there is some veering, very low level inhibition and lower to mid level dry air has shut out shower activity near the island chain.

Over the course of the day, troughing moving through the eastern United States and associated weak lower level troughing developing across the peninsula will push out the surface ridge. This along with day time heating will help to relax breezes as they clock southwesterly. Low level inhibition and limited lower to mid level moisture will help to keep rain chances minimal. There is considerable uncertainty regarding fog potential late today into tonight. Surface dew points are expected to fall into the upper 60s overnight with the northerly flow. This along with water temperatures near or slightly below 70 on our gulf waters should provide a window for fog and low ceilings across portions of the Middle and Lower Keys.

The lower level trough across Florida will lift out to the northeast tonight as modest surface ridging expands southeastward from the southeastern United States. This will help to firm up northeasterly breezes. Winds coming in out of the northern half of the compass will help nudge dew points down further into the mid 60s. Temperatures should remain slightly above normal with highs in the upper 70s to near 80 and lows near 70.

A lengthy stretch of near breezy or breezy conditions are expected to set in heading into mid week as a beefy anticyclone builds southeastward off of northeastern North America. Breezes will begin trending upwards late Sunday and remain moderate to fresh through much of the week. These moderate to fresh breezes will gradually clock further east northeasterly to east over the ensuing days as the high builds out into the Atlantic. Expect a fairly static pattern through much of the week with highs near 80, lows near 70, and dew points in the upper 60s. The fast flow and deepening boundary layer should result in slight to low chance for showers.

MARINE

Issued at 1113 AM EST Sat Feb 28 2026

No watches, warnings, or advisories are currently in effect for the coastal waters of the Florida Keys. From synopsis, an Atlantic ridge across South Florida will pull further east while a frontal boundary stalls across north central Florida. The combination of these features will result in light breezes likely becoming variable later today. Thereafter, a broad high pressure system is forecast to migrate into the eastern United States, then out into the Atlantic. This is expected to support freshening breezes, especially across the Straits of Florida. A mix of Cautions and Advisories is becoming increasingly likely for the bulk of the work week.

AVIATION

(15Z TAFS) Issued at 1113 AM EST Sat Feb 28 2026

VFR conditions will prevail through the early this afternoon for EYW and MTH. As light near surface winds turn to the north later today, a window of low ceilings and fog will be possible as it advects in from the Gulf. Uncertainty is still relatively high as these features have yet to coalesce and depends on when the wind direction changes from variable to northerly.

PRELIMINARY POINT TEMPS/POPS

Key West 82 68 78 69 / 0 10 0 10 Marathon 79 68 78 70 / 0 10 10 20

KEY WATCHES/WARNINGS/ADVISORIES

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