Long Key, Florida Weather Forecast Discussion

775
FXUS62 KKEY 301526
AFDKEY
Area Forecast Discussion
National Weather Service Key West FL
1126 AM EDT Tue Sep 30 2025
...New DISCUSSION, MARINE, AVIATION...
.DISCUSSION...
Issued at 1125 AM EDT Tue Sep 30 2025
Mostly clear skies prevail across the Florida Keys on this final
morning of September. GOES-19 visible imagery notes fair weather
cumulus dotted along broken lines stretched across the island
chain. A small meso low circulation can also be spotted in our
deep Gulf waters drifting southeast. Meanwhile, KBYX radar detects
a few shallow showers pulsing along these boundaries. These
showers have generally remained offshore resulting in a fairly dry
start to the day. Moderate west to northwest breezes are observed
along the Reef and after a brief uptick from this morning seem to
be fairly stable for now. While the drier conditions and
northerly influenced wind direction may make it seem like a fall
day outside, temperatures in the mid to upper 80s remind us that
it is still September, especially with dewpoints in the mid 70s.
This morning`s KKEY 12z sounding was another dry one with a PW
value below the 25th percentile for today. CIMSS MIMIC PW confirms
this with a clear streak of low values situated over most of the
island chain. The current low level wind direction will continue
to advect dry, modified continental air over the Keys today
resulting in slight chance PoPs for the rest of the day. As
Tropical Storm Imelda is progged to drift east into the North
Atlantic, breezes will gradually slacken and veer starting tonight.
Moderate west to northwest breezes will become gentle to moderate
and more northerly overnight into tomorrow. Residual moisture from
Imelda as well as a more moist wind direction will slide PoPs up
to more seasonable values later tonight and into tomorrow. High
pressure building along the Eastern Seaboard will gradually shift
conditions back to near normal by the end of the week.
&&
.MARINE...
Issued at 1125 AM EDT Tue Sep 30 2025
A Small Craft Advisory remains in effect for the eastern Straits
of Florida. From synopsis, Tropical Storm Imelda, located east of
the northeast coast of Florida, will continue to move slowly
northward, then make a sharp eastward turn today into the west-
central North Atlantic. Moderate to fresh northwesterly breezes
will slacken by tonight. High pressure over the Eastern Seaboard
will slowly slide eastward into the western North Atlantic, with
mainly gentle northwesterly breezes eventually veering to the
northeast to east for the middle to latter part of the work week.
Winds will then clock around towards the southeast towards the end
of the week and into the upcoming weekend.
&&
.AVIATION...
(15Z TAFS)
Issued at 1125 AM EDT Tue Sep 30 2025
VFR conditions will prevail at both EYW and MTH today. While a few
stray showers cannot be ruled out, uncertainty in exact location
and timing will leave mention out for now. Near surface winds will
be out of the west to northwest at near 10 knots with occasional
to frequent gusts to near 15 knots.
&&
.CLIMATE...
On this day in Keys Weather History, in 1945, a record low
temperature of 69 was recorded at Key West. This is also tied for
the coldest temperature recorded during the month of September.
Temperature records for Key West dates back to 1872.
&&
.PRELIMINARY POINT TEMPS/POPS...
Key West  89  79  88  79 /  10  20  20  30
Marathon  89  79  88  79 /  20  30  30  30
&&
.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...Small Craft Advisory until 9 PM EDT this evening for GMZ052-072.
&&
$$
Public/Marine/Fire...JAM
Aviation/Nowcasts....JAM
Data Acquisition.....JAM
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NWS KEY Office Area Forecast Discussion