Update AFD Area Forecast Discussion — Mon Apr 6, 2026 4:39 AM

AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
425 AM EDT Mon Apr 6 2026

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

.KEY MESSAGES...

- Light to gentle easterly breezes are expected through Tuesday to
  Tuesday night. Passing showers are possible, but significant
  rainfall is not likely through tonight.

- There is high confidence for a chance of showers and
  thunderstorms mid week, but confidence in the wind forecast is
  low.

- Breezy conditions may be able to return late in the week.

&&

.DISCUSSION...
Issued at 430 AM EDT Mon Apr 6 2026
Showers were percolating with more energy than the past few days
across the Florida Keys coastal waters. KBYX radar scans show
shallow, disorganized showers across the eastern waters, and some
locations in the Middle and Upper Keys likely observed at least a
trace of rainfall. Nighttime microphysics returns from GOES East
are able to highlight some of the nighttime showers, but drier air
aloft is putting a cap on this early morning rainfall. Last
night`s 00Z sounding sampled a very dry mid atmosphere, so for the
moment thunderstorm chances are very low. While the upper
atmosphere is dry, moisture levels near the surface are slowly
rising. Dew points across the island chain are near 70 degrees,
and GOES East sampled a derived PWAT near 1.45 inches just upwind
of the Keys. Today, we have high confidence that the weather will
be humid with light to gentle breezes, and just a little bit
warmer than normal.

Later this week, the environment becomes much more complicated. A
high pressure system descending out of central Canada into the
Northern Plains will be sufficient to force a frontal boundary
towards South Florida by tomorrow morning. The uncertainties
revolve around where, exactly, the front stalls. Recent
statistical models suggests the front will stall further north.
This scenario places a general warm sector environment directly
over the Florida Keys for most of the week. These conditions could
start as soon as early Tuesday morning when moisture replaces the
drier air aloft.

In contrast to the precipitation forecast, there is low confidence
in the wind forecast later in the week. The strength of easterly
breezes across the Keys depends on where and when the frontal
boundary stalls. The difference between the 10th and 90th
percentile wind speeds over the island chain on Wednesday is
almost 13 mph. The current consensus favors light to gentle
breezes as the frontal boundary approaches the Keys, gentle to
moderate breezes after the boundary stalls, and then freshening
to moderate to fresh breezes late in the week after the Atlantic
High rebuilds enough to force the boundary south of the Keys. The
pattern is complex, and it will not be a shock if the wind
forecast changes by tomorrow morning. However, the prolonged
period of moisture will be much appreciated.

&&

.MARINE...
Issued at 430 AM EDT Mon Apr 6 2026
No watches, warnings, or advisories are in effect for the Florida
Keys coastal waters. From synopsis, breezes slackened to light to
gentle breezes across the Florida Keys nearshore waters over the
weekend. There is high confidence these lighter near surface winds
will persist through Tuesday to Tuesday night. A high pressure
system building over the Northern Plains early this week will be
sufficient to force a frontal boundary south towards the Florida
Keys. There is high confidence that the environment will favor
widespread showers and a chance of thunderstorms midweek. However,
whether gentle or fresh to strong breezes are observed over the
Keys waters before the weekend depends on where the frontal
boundary moves. The current forecast places more confidence on the
front stalling north of the Outer Gulf waters.

&&

.AVIATION...
(06Z TAFS)
Issued at 430 AM EDT Mon Apr 6 2026
VFR conditions will prevail at both EYW and MTH for the upcoming
TAF period. Short lived showers will be able to form near the
island terminals, but there is not enough confidence in where and
when to try to time VCSH in the TAFs. MVFR CIGs will be able to
form near showers, not at sufficient frequency to require a TEMPO.
Near surface winds will remain below 10 knots. Shower coverage is
expected to decrease after sunrise.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  83  72  81  69 /  20  30  40  40
Marathon  82  72  80  70 /  20  40  50  50

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&

$$