Key West Naval Air Station Florida Weather Forecast Discussion

276
FXUS62 KKEY 100841
AFDKEY
Area Forecast Discussion
National Weather Service Key West FL
441 AM EDT Fri Oct 10 2025
...New DISCUSSION, MARINE, AVIATION...
.KEY MESSAGES...
-Peak rain chances today (90%), then slightly decreasing rain
 chances tonight (80%) as the non-tropical low begins to pull
 away from the area.
-A Coastal Flood Advisory remains in effect for all Florida Keys.
 The combination of the current King Tide cycle and persistent
 bouts of rainfall will support additional flooding over roadways
 and low lying lots. Coastal flooding will likely continue into
 the weekend.
-A weak cold front is anticipated to move through the Keys over
 the weekend. This will usher in drier air offering the first
 taste of Florida Fall to the Keys into early next week.
&&
.DISCUSSION...
Issued at 438 AM EDT Fri Oct 10 2025
The active pattern remains in place across the Keys. KBYX radar
has remained active all night with scattered to numerous showers
with some thunderstorms from time to time. The radar loop depicts
a cyclonic flow across the area. Showers were moving from
northwest to north across the eastern portions of the area with
the activity across the western areas moving from west to
northwest. Looking even more closely, we can potentially depict
where the center of the low pressure. The activity just outside
of the Keys to the north of western Cuba is moving southwest to
south, even slightly southeasterly. MRMS data shows estimated
rainfall accumulations of generally a trace to a quarter of an
inch overnight, though the heaviest rainfall has so far been over
the marine area. Temperatures along the Island Chain are in the
upper 70s to near 80 degrees with dew points in the mid 70s.
Marine platforms around the Keys are observing southeast to south
breezes near 5 knots.
.FORECAST...
The aforementioned low pressure system will continue moving north
to northeast today while slowly strengthening. It will continue
becoming better organized as it moves north northeastward to a
place off of the Mid-Atlantic coast by Sunday. GOES East Total
Precipitable Water (TPW) shows PWAT values remain quite juicy
early this morning. Most of the Keys are seeing PWAT values above
2 inches even approaching 2.3 inches in some instances. In
addition, an upper trough continues to dig southward across the
southeast Gulf today and tonight. At the surface, this will induce
a surface low, which we are already seeing signs of when looking
at radar. We also have ample instability in place with the 00z
sounding last evening showing almost 2000 J/kg of CAPE. Therefore,
all the ingredients are there for today to be quite active in
terms of more widespread shower and thunderstorm coverage. We
don`t expect any of this activity to be strong, more garden
variety for the thunderstorms with the typical gusty winds.
Therefore, PoPS were increased for today and tonight from 80% -->
90% and then 70% --> 80% respectively.
As this low continues to develop and strengthen while moving
north northeastward, it will begin to send a cold front southward
along the Florida Peninsula. There still remains some uncertainty
as to exactly how far south the front will go. One thing to
remember is that it is still early on in the season for a cold
front to fully push through the Keys, though it is still possible
under the right conditions. Latest thinking is the front may just
clear the Island Chain and then remain over the Straits for a few
to several days. Initially, drier air will make it into most if
not all of the Keys for the second half of the weekend into early
next week, though some lingering moisture is possible in the low
levels of the atmosphere. 10% PoPs are in the forecast along with
no thunder as a result.
Towards the middle to latter part of next week, there are some
signals of this front lifting back as a warm front. If this
occurs, moisture may return to the area along with some
instability. For now, PoPs remain at 20% for Monday night through
Thursday with no thunder chance. Stay tuned.
&&
.MARINE...
Issued at 438 AM EDT Fri Oct 10 2025
There are currently no watches, warnings, or advisories in effect
across the Florida Keys coastal waters. From synopsis, a non-
tropical surface low located over western Cuba will continue to
slowly drift northward today and then north northeastward tonight.
This will support bouts of elevated rain and thunder chances. The
low will initially support light to gentle southeast to south
breezes this morning. However, as the low moves north
northeastward, breezes will veer to the northwest to north over
the weekend. Low pressure will continue organizing and
strengthening as it heads northeastward adjacent to the Mid-
Atlantic coast. As it does this, it will drive an early season
cold front towards the Keys, further shifting winds to the north
to northeast. Northerly swells will be possible in our western
marine zones today and through the weekend due to the influence of
the low pressure system.
&&
.AVIATION...
(06Z TAFS)
Issued at 438 AM EDT Fri Oct 10 2025
VFR conditions are expected to mostly prevail at the terminals
through the TAF period. That said, periods of showers and an
occasional thunderstorm are likely throughout the period. This is
addressed via continuous inclusion of VCSH for the entire period.
It is likely that CIGs and visibility may be reduced to MVFR or
IFR when these occur at the terminals, but given the uncertainty
of timing, elected to only address this via TEMPO before 12z.
Later categorical changes will be addressed via amendment and
routine TAF issuances. Southeast winds 5 to 10 knots will become
south to southwest by this afternoon.
&&
.CLIMATE...
On this day in Keys Weather History, in 1888, the daily record
low temperature of 66F was recorded at Key West. Temperature
records for Key West date back to 1872.
&&
.PRELIMINARY POINT TEMPS/POPS...
Key West  84  78  86  78 /  90  80  50  20
Marathon  86  76  86  76 /  90  80  50  30
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 6 AM EDT Saturday for FLZ076>078.
GM...None.
&&
$$
Public/Marine/Fire...MJV
Aviation/Nowcasts....MC
Data Acquisition.....MC
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NWS KEY Office Area Forecast Discussion