Area Forecast Discussion
Issued by NWS Key West, FL

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FXUS62 KKEY 151741
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
141 PM EDT Tue Sep 15 2026

...New AVIATION...

.KEY MESSAGES...

- Near normal rain chances (around 30-40%) through tonight will
  give way to considerably higher rain chances for the remainder
  of the work week and at least the first half of the weekend.

- Our current confidence in the rainfall totals is low, although
  most locations in the Keys can generally expect 1 to 3 inches,
  with locally higher amounts, through Saturday.

- Easterly breezes will trend upwards over the next several days,
  peaking Wednesday through Thursday (10-15 mph).

&&

.AVIATION...
(18Z TAFS)
Issued at 132 PM EDT Tue Sep 15 2026
While VFR conditions will prevail across the terminals through
18z Wednesday, there will be several opportunities for showers
and thunderstorms in the vicinity of the terminals. This includes
a developing cloud line near EYW through the late afternoon
hours, convection pushing off the Mainland in the evening, and
late overnight activity through the remainder of the TAF period
in modestly confluent flow. Have elected to include a general
window for VCSH for now due to a lack of confidence in evolution,
although this will be reevaluated at the 00z TAF issuance.

&&

.PREV DISCUSSION...
Issued at 400 AM EDT Tue Sep 15 2026
Over the next couple of days, a robust continental high will
spread south and southwestward through the southeastern United
States and gradually bolster the local pressure gradient. Expect
light east to southeasterly breezes to freshen modestly later
this afternoon and evening out of the northeast to east. Deep
layered moisture is expected to slip slightly through the day with
weak lower level inhibition holding on. As a result, expect near
normal shower and thunder chances today. Island cloud lines will
once again be possible. Temperatures will remain trend less with
highs near 90 and lows in the lower 80s. Dew points will hold in
the mid 70s.

The tail end of the sharp trough digging off the Atlantic coast
is expected to pinch off and interact and absorb a TUTT cell
moving in across Hispaniola and the Central Bahamas through the
middle portion of the week. As a result, deep layered moisture is
expected to increase across and east of our area as broad lower
level troughing takes shape. The mid and upper level low and
lower level trough is expected to sweep westward into our area
through the back half of the week. In addition, the mid and upper
low complex will result in falling heights aloft. Expect shower
and thunder chances to trend sharply upwards through the middle of
the week, likely peaking in the Thursday time frame. Breezes will
gradually relax and veer east to southeast as the trough pushes
through.

It may take some time for the copious atmospheric moisture to
clear out of our area. The trough/low complex should slowly
lumber westward into the Gulf while broad ridging sets up off the
Atlantic Coast. This will keep a broad moist confluent zone
across our area for quite some time. Consequently, a prolonged
period of above normal rain chances are possible through late week
and weekend. With all that said, the evolution of these features
are highly uncertain as is often the case with complex upper level
interactions. that said, uncertainty is high and model to model
and run to run disagreement is high.

&&

.MARINE...
Issued at 1030 AM EDT Tue Sep 15 2026
No watches, warnings, or advisories are in effect for the Florida
Keys nearshore or offshore waters. From synopsis, light east to
southeasterly breezes will gradually back to the northeast to east
and freshen this afternoon and evening, as a continental high
builds southward towards our area. Expect breezes to peak in the
moderate range this evening through late Wednesday. Near normal
rain chances will trend considerably upwards through mid week, as
broad troughing in the western North Atlantic and increased
moisture retrogrades southwestward towards the Keys.

&&

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

$$

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

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