Update AFD Area Forecast Discussion — Sun Apr 5, 2026 11:12 AM

AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
1103 AM EDT Sun Apr 5 2026

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

.KEY MESSAGES...

- Breezes will gradually slacken today, and there is high
  confidence breezy conditions will remain out of the forecast
  for the start of the week.

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

- Although passing showers are possible, significant rainfall is
  not likely for the next few days.

- 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 957 AM EDT Sun Apr 5 2026
The Easter Bunny has had a pleasant trip along the Florida Keys
this morning. Automated surface observations have been reporting
mild morning temperatures near 80F coupled with dew points in the
lower 70s. Breezes are in the process of gradually diminishing,
and the sparse surface observations we have available to us are
reporting sustained winds near 15 mph. Occasionally, these
automated obs will show a gust observation, but these are coming
in much less frequently compared to the past few days.

Visible satellite shows a widely spread field of cumulus clouds,
but plenty of sunshine is making it through the breaks in the
clouds. Our KBYX radar is detecting some shower activity across
the area, mainly across the distant Florida Straits south of the
Lower Keys. Based on the narrow appearance of the shower activity,
there may be a localized area of surface- level convergence
triggering this activity. The 12Z sounding from the morning
radiosonde launch shows a reasonably moist profile from the
surface up to near 700mb. Within this layer, winds veer ever so
slightly. If there truly is some convergence still out there, the
current chance of showers, 30%, seems reasonable to carry through
this morning update. No changes to the current forecast package
are proposed at this time.

&&

.PREV 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 957 AM EDT Sun Apr 5 2026
Small Craft Should Exercise Caution Until Winds Decrease across
all Florida Keys local waters. From synopsis, breezes will
continue to slacken while an Atlantic high weakens and moves
farther 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...
(12Z TAFS)
Issued at 957 AM EDT Sun Apr 5 2026
VFR conditions will prevail through the TAF period. If any MVFR
CIGs are observed, they will be short lived and infrequent as a
low level cloud field brushes the area. East surface winds of 10
to 15 knots will occasionally gust to near 20 knots, but the
frequency of these gusts will decrease over the course of the
period. TAFs will remain dry even with showers to the south of the
area, but we cannot rule out a stray shower brushing either
terminal.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  83  73  83  72 /  20  20  20  30
Marathon  82  74  81  73 /  30  30  30  40

&&

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

$$