textproduct: Key West

KEY MESSAGES

- High uncertainty remains regarding the wind forecast. Winds will generally be gentle to moderate out of the northeast to east. However, large swings both up and down will be possible. - Well above normal rain and thunder chances will continue over the next couple of days.

- Increased cloud cover and convective coverage will help to keep temperatures closer to near normal levels over the next few days.

DISCUSSION

Issued at 1010 AM EDT Thu Jun 4 2026 The Florida Keys received a well-needed dose of rainfall over the past 24 hours. A daily total of 1.21 inches was measured last night at the Key West office. Multiple COCORAHS observations in Key West also reported over an inch of rainfall. The most rainfall yesterday occurred at Long Key, where over 3 inches of estimated rainfall occurred per 24 hour MRMS estimates.

Shower activity waned after sunrise across the Keys. A feature called a Mesoscale Convective Vortex, or MCV, was observed just north of Key West, and that feature played a role in maintaining the stratiform precip observed around sunrise in the Lower Keys. While MCVs typically move east, observations from both KBYX and KAMX in Miami suggest the vortex is moving north. These observations line up with GOES East scans over the Gulf, where an upper level trough located west of the Keys is slowly lifting north. What this means for weather over the Keys is a high degree of unpredictability. Deep layers of moisture linger over the Keys, despite the amount of rainfall. The morning KKEY sounding sampled another day of near record PWAT over the Lower Keys. Despite the amount of moisture, the lull in activity is likely to last until the afternoon. CAMS models suggest the environment will destabilize before sunset, so another round of showers is possible. The greatest source of uncertainty is the wind forecast. High pressure developing over the eastern United States suggests freshening breezes, but the timing is uncertain. Plus, a weak frontal boundary is stalled just south of the Florida Keys. Even though winds should be increasing based on the synoptic pattern, local scale effects will interfere with the pressure gradient. Overall, expect weather to be very chaotic this afternoon and this evening. PoPs will remain elevated, so no changes were made to the inherited forecast.

PREV DISCUSSION

Issued at 430 AM EDT Thu Jun 4 2026 Over the next couple of days the combination of the eastern United States high and a surface trough over the central Gulf will keep winds gentle to moderate across the Keys. Deep layered moisture will remain quite elevated, with inhibition remaining low with moderate CAPE. As a result shower chances will remain well above normal with a chance for thunderstorms. Wind surges will continue to be possible, but probably not as strong as what we saw last evening. Will maintain likely to categorical PoPs for today through tomorrow. The continued increased cloud cover and convective activity should help to keep temperatures down near or slightly below normal with dew points holding in the lower to mid 70s.

Head into the weekend, mid to upper level ridging building northeastward across the Gulf will link with ridging driving eastward across the southeastern States. This will gradually push in much drier air through the mid and upper levels, and eventually the lower levels. Meanwhile, the eastern United States surface high will move southeastward off the Carolina Coast on Friday and then eastward out into the Atlantic over the following few days. This should allow easterly breezes to trend downwards slightly. There is still some uncertainty due to broad troughing expected to setup across Cuba in this time frame. Expect rain chances to fall closer to normal with temperatures climbing back above normal. Dew points should remain in the mid 70s.

Through early next week, deep layered ridging will hang on across out region with surface ridging setting up across the southeastern United States. While the fine details imparted by the previously mentioned weak troughing across Cuba will keep some measure of uncertainty, in general winds will be light to gentle broadly out of the southeast. Elevated lower level moisture will continue to harass the region through this period. Expect slight to low chance for precipitation and a few thunderstorms will remain possible.

MARINE

Issued at 430 AM EDT Thu Jun 4 2026

Expansive high pressure building southeastward into our area will maintain gentle to moderate northeast to easterly breezes over the next few days. A very disturbed environment may result in periodic wind surges into moderate to fresh range. Winds should gradually trend downwards this weekend, however, uncertainty continues to be high.

AVIATION

(12Z TAFS) Issued at 1010 AM EDT Thu Jun 4 2026 A wet pattern continues across the Florida Keys this afternoon. Expect periods of MVFR to IFR conditions, in spite of the prevailing VFR weather. Near surface winds are expected to gradually increase near hte end of the period. Another round of showers is expected later this afternoon.

PRELIMINARY POINT TEMPS/POPS

Key West 87 77 87 78 / 70 60 70 50 Marathon 86 77 86 78 / 80 60 70 40

KEY WATCHES/WARNINGS/ADVISORIES

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