Area Forecast Discussion
Issued by NWS Key West, FL

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695
FXUS62 KKEY 012009
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
309 PM EST Mon Dec 1 2025

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

.KEY MESSAGES...

-Gentle to moderate breezes will become shift to the southeast
 towards early Tuesday morning.

-Breezes will continue to clock around the compass while
 continuing to slacken through Wednesday as the next frontal
 system approaches due to developing low pressure along the Mid-
 Atlantic to New England coastlines. This could set up for
 potential foggy conditions Tuesday night into Wednesday.

-A benign forecast is anticipated for much of the week with rain
 chances near nil, increased humidity initially, before a dip
 with frontal passage mid week before increasing again by the
 weekend. Temperatures will also remain above normal early week,
 near normal mid week, and then above normal again by the weekend.

&&

.MARINE...
Issued at 309 PM EST Mon Dec 1 2025

A broad high pressure currently across the Great Lakes
region will move into the New England States this evening. At the
same time, an area of low pressure across the far western Gulf
Basin as it moves into the North Gulf Coast area. This will clock
winds around the compass, coming out of the east tonight and
coming out from the south Tuesday. A corresponding cold front is
expected to press through the Keys by early Wednesday morning. As
this front approaches the area, breezes will initially slacken and
could promote fog development. In the wake of the frontal passage
breezes will freshen and shift north to northeast.

&&

.AVIATION...
(18Z TAFS)
Issued at 309 PM EST Mon Dec 1 2025

VFR conditions will prevail through the forecast period. Easterly
winds this afternoon and evening will become southeast to south
overnight into Tuesday morning. Winds will further veer out of the
southwest to west towards Tuesday afternoon. While a brief period
of crosswinds will occur, the magnitude will be around 10 knots.

&&

.PREV DISCUSSION...
Issued at 428 AM EST Mon Dec 1 2025

The humidity is back at least for the next few days across the
Florida Keys. Temperatures along the Island Chain are in the lower
to mid 70s and dew points are in the lower 70s. This is making it
feel quite humid and sticky to start the new and final month of
2025 (December). KBYX radar has been detecting isolated to
scattered showers all night. The heaviest and most widespread
activity has been across the southwestern distant Straits of
Florida with more isolated activity elsewhere, mainly south of the
Island Chain. However, occasionally a couple showers have been
able to affect a few island chain communities, mostly in the
Middle and Upper Keys. GOES 19 Nighttime Microphysics imagery
shows some low level clouds throughout the Keys with an area of
high clouds across the southwestern Straits moving southeastward
towards Cuba. Another large surface high pressure system is
located over the Lower Great Lakes region. This is promoting
gentle to moderate northeast to east breezes at marine platforms
surrounding the Island Chain.

.FORECAST...
The aforementioned high pressure will continue to move to the east
over the next 24 hours. Therefore, expect mainly gentle to
moderate northeast to east breezes to continue through this evening
before shifting to the east to southeast and further slackening
overnight through Tuesday night. Moisture also continues to lurk
over the area early this morning. GOES 19 Total Precipitable Water
(TPW) products shows estimated PWAT values of 1.4 to 1.6 inches
throughout the Keys. While moisture is lingering, most of the
shower activity has remained over the marine area. This is
expected to be the main theme for today resulting in a dry
forecast for the Island Chain. However, we do keep the rain
chances over the Straits of Florida, especially the west side.

As this high continues moving off to the east, a storm system will
begin to quickly develop on its heels. This system will become a
Nor`easter as it moves northeastward to a place just off the New
England coastline by Tuesday evening. However, the item of
interest for the Keys will be another frontal boundary which is
expected to approach and then move through the Keys sometime mid
week. However, before we get to frontal passage, there may a time
frame early Tuesday evening into Wednesday morning where the
winds go light and variable along with dew points in the lower to
mid 70s. While we are still early on in the season, there is the
potential for sea fog to develop early Tuesday evening through
Wednesday morning. We are cooling the SST`s with each frontal
passage and with dew points in the mid 70s along with light and
variable wind flow, this could set the stage for a window of sea
fog. We will continue to keep an eye on this.

After the potential brief window for fog, the aforementioned front
is expected to press through the Keys sometime Wednesday. This
will result in winds clocking around the compass becoming north to
northeasterly Wednesday night into Thursday. Accompanying the
freshening winds will also be a dip in the dew points, potentially
back into the mid to upper 60s along with a few degrees drop in
temperatures. Moisture is expected to be remain rather meager
through much of the week resulting in a dry forecast. However,
rain chances will be lurking nearby, mainly over the marine area
surrounding the Keys.

In the wake of the front, a series of much weaker high pressure
systems will traverse across the eastern United States as the
pattern remains progressive. Therefore, expect breezes to continue
to clock around the compass this week as multiple frontal systems
approach and try to press through the Keys. Rain chances remain
near nil for the Island Chain through late week before slight
chances creep back in for the second half of the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  75  83  73  79 /  10  10  10  10
Marathon  74  83  72  79 /   0  10  10  10

&&

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

$$

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

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