textproduct: Key West

KEY MESSAGES

- Light to gentle north to northeast breezes this morning may strengthen to a gentle to moderate northeast to easterly breeze this afternoon. The wind forecast is unusually uncertain for the next few days, and large swings both up and down will be possible. - Rain and thunder chances will continue the trend upwards, peaking Wednesday night and Thursday.

- Increased cloud cover and convective coverage will help to trend temperatures down to near normal over the next few days.

DISCUSSION

Issued at 430 AM EDT Wed Jun 3 2026

A mid latitude trough reaches southwards into the far southeastern United States. This is driving cyclogenesis off the Carolina Coast as an expansive high builds across the eastern United States. For the Keys, this has resulted in a very weak and poorly defined wind field this morning. The broad swath of high moisture remains draped across our area. This past evenings sounding indicated precipitable water was just above 2 inches, but there were a couple of bands of relatively drier air and some weak low level inhibition. Convection was able to fire across mainly the Upper Keys and surrounding waters as a result of relic boundaries moving off of the mainland. Temperatures currently range in the lower to mid 80s with dew points in the lower to mid 70s.

A fairly complicated evolution of our weather is expected over the next few days. The mid latitude trough will continue to swing off of the Atlantic Coast and the associated surface low will deepen as it migrates northeastward just off the Atlantic Coast. At the same time the eastern United States surface high will build southward reaching into the Keys and steadily push a weak surface frontal boundary through South Florida and eventually the Keys. Adding to this mess, a southern stream upper trough over the Gulf will result in the formation of a central Gulf low that will slowly lumber its way northward as it deepens. The band of increased moisture will remain across our area and CAPE will remain at least modest. Altogether, this points to a several day period of much higher than normal rain and thunder chances, as well as the threat of bouts of moderate to fresh northeasterlies to easterlies. There is considerable uncertainty regarding wind speeds through the remainder of the week. The incoming freshening northeasterlies, along with increased cloud cover and convective activity will help to stymie the recent hot weather. Expect highs and lows to trend back towards normal over the next couple of days, remaining there through the remainder of the week. Dew points will likely remain in the lower to mid 70s, with some slight lowering later in the week as drier air moves in around the surface high.

Towards and through the weekend, strong mid to upper level ridging will build northeastward across the Gulf of America. This will result in mid level warming, reducing CAPE significantly. However, lower level moisture will remain quite high and inhibition will generally be limited. The old eastern United States surface high will steadily migrate southeastward off the Carolina Coast on Friday and eastward out into the Atlantic through the weekend. Expect broadly easterly breezes to trend downwards and rain chances fall back to normal climatology at a slight to low chance. With this temperatures will rebound to slightly above normal with dew points returning to the mid 70s.

MARINE

Issued at 430 AM EDT Wed Jun 3 2026

A robust surface high blanketing the eastern United States will build southward across our area today. Meanwhile, a low pressure system in the Gulf of America will gradually take shape and deepen over the next few. In addition, shower and thunderstorm activity is expected to ramp up, peaking tonight or Thursday. The combination of the above will result in light breezes this morning increasing to at least gentle to moderate this afternoon. There is the potential for periods of stronger breezes. However uncertainty is unusually high, and will be dependent on how far south the high builds, the strength and position of the Gulf low, and the extent and nature of showers and thunderstorm activity. Heading into late week and this weekend, the high will swing southeast and eastward into the Atlantic and the Gulf low will lift into the central Gulf Coast. In response, breezes will gradually trend downwards, as will rain chances.

AVIATION

(00Z TAFS) Issued at 430 AM EDT Wed Jun 3 2026

A wet pattern is taking shape across the Keys. As a result, while VFR conditions will prevail, bouts of MVFR and IFR conditions will become increasingly possible. Surface winds, away from convective activity, will start out light and predominantly easterly, with a lot of variability. Convective influences may bump northeast to easterly breezes up into the gentle to moderate range this afternoon.

KEY WATCHES/WARNINGS/ADVISORIES

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