Update AFD Area Forecast Discussion — Sun Apr 5, 2026 4:24 AM

AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
415 AM EDT Sun Apr 5 2026

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

.KEY MESSAGES...

- Breezes are primed to gradually slacken today, and there is high
  confidence breezy conditions will abate for the start of the
  week.

- Small Craft Should Exercise Caution until winds decrease for all
  Keys coastal waters.

- Although passing showers are possible, especially overnight,
  significant rainfall is not expected Sunday into Monday.

- There is increasing confidence for above normal shower and
  possible thunderstorm chances for Tuesday and Wednesday. Low to
  medium confidence in potential breezy conditions on Tuesday
  night.

&&

.DISCUSSION...
Issued at 415 AM EDT Sun Apr 5 2026
After days of breezy weather across the Keys, the winds are
finally beginning to slacken today. While breezes are still fresh
to strong across Keys nearshore waters, winds at both airports
slackened below breezy thresholds during the early nighttime
hours. However, lighter breezes do not mean no weather. The KBYX
radar detected more showers than usual across the Keys coastal
waters. Multiple locations across the Middle and Lower Keys
observed at least a trace of rainfall. Satellite observations, and
the evening KKEY sounding, suggest a plume of moisture is
beginning to move over South Florida. Weather across the Florida
Keys, after a long dry spell, is trending back towards a wet
patten this Sunday.

Zooming out to look at the synoptic scale, one can see a well
developed low pressure system over northern Ontario and Quebec.
This low, its associated mid level trough, and the eastward
movement of the Atlantic high are why winds are slackening across
the Keys. Mid level winds are also veering southeasterly, which is
bringing additional moisture towards the Keys. The climatological
chance for showers is around 10 percent in April, and there is
high confidence in a chance of showers through Tuesday.
Thunderstorms may be able to form starting on Monday as well.

Past Tuesday morning the confidence in the forecast drops
significantly. Yesterday, statistical models indicated a prolonged
breezy, possibly windy, period across the Florida Keys this week.
Last night and this morning`s model runs instead show a delay in
breezy conditions until Friday. What happened? A cold frontal
boundary located over the eastern United States will meander east
to southeast towards South Florida this week. While prior models
suggested faster movement of the front, the recent model runs
stall it over South Florida until Thursday to Friday, which means
the pressure gradient does not tighten across the Keys. This also
means a stalled source of lift would be located just north of the
island chain. The resulting forecast shows higher chances of
showers midweek, and statistical guidance suggests PoPs as high
as 60 to 70 percent. However, this is not a confident forecast at
this time. Model runs may shift back towards a faster front
tomorrow. Either way, the Keys may get some much needed rainfall
this week.


&&

.MARINE...
Issued at 415 AM EDT Sun Apr 5 2026
Small Craft Should Exercise Caution until winds decrease for all
Keys coastal waters. From synopsis, breezes will continue to
slacken while the Atlantic high weakens and moves further east.
There is high confidence that light to gentle breezes will persist
through Tuesday. A high pressure system descending into the
Northern Plains on Tuesday night will push a frontal boundary
south towards the Florida Keys. Considerable uncertainty surrounds
where the front will stall, and when breezes will freshen later
this week. In contrast to the wind field, there is high confidence
for a chance of showers with a slight chance of thunderstorms mid
week.

&&

.AVIATION...
(06Z TAFS)
Issued at 415 AM EDT Sun Apr 5 2026
VFR conditions will prevail at EYW and MTH. Short lived periods
of MFVR VIS or CIGs may occur if showers move near the island
terminals. Winds will slacken during the day, and prevailing gusts
are not anticipated by sunset. While VCSH is left out of the
TAFs, that does not mean no showers are present. Short lived
showers are expected over the waters surrounding the Keys, but
confidence is not high enough to include VCSH.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  83  73  82  72 /  20  30  30  30
Marathon  82  74  82  72 /  30  30  30  30

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...Small Craft Advisory until 5 AM EDT early this morning for
     GMZ031>035-042>044-052>055-072>075.

&&

$$