Area Forecast Discussion
Issued by NWS Key West, FL

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670
FXUS62 KKEY 041407
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
1007 AM EDT Thu Jun 4 2026

...New DISCUSSION, MARINE, AVIATION...

.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.
&&

$$

Public/Marine/Fire...AJP
Aviation/Nowcasts....AJP
Data Acquisition.....AJP

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