Small Craft Advisory 4, NWS Key West, FL

Area Forecast Discussion
National Weather Service Key West FL
1255 PM EST Mon Jan 26 2026

...New AVIATION...

.KEY MESSAGES...

-A potent cold front will race southeastward through the Florida
 Keys late today or this evening. In wake of the front, winds will
 clock northwest to north and freshen considerably. Near gale
 breezes will be possible. A Small Craft Advisory conditions
 expected for all Keys waters by this evening.

-The cold air mass behind the front along with one, possibly two,
 reinforcing front(s), have a good potential of keeping
 temperatures well below normal for the duration of the week.

-The reinforcing fronts will contribute to additional periodic and
 significant wind surges through the week.

&&

.AVIATION...
(18Z TAFS)
Issued at 1252 PM EST Mon Jan 26 2026
VFR conditions will prevail at both EYW and MTH through around 21z.
A cold front is moving through our waters bringing in a line of
showers and behind that, cloudy and windy conditions. MVFR to IFR
CIGs will be possible and TEMPOs will be included if need be
later this evening (around 21-00z). Near surface winds will
quickly become west to northwest at near 15 knots and frequent
gusts of near 25 knots around sunset. Tonight, around 00z, winds
will turn to the northwest to north while staying elevated,
potentially posing crosswind concerns.

&&

.PREVIOUS DISCUSSION...
Issued at 400 AM EST Mon Jan 26 2026

Big changes are coming for Keys weather this week. To start things
off, a potent cold front will drive southeastward across the Gulf
and through the Keys today into tonight as a strong mid latitude
trough moves through the eastern United States. Ahead of the
front, a prefrontal trough will swing through South Florida and
the Keys. Surface winds will firm up modestly out of the west.
Highs today will be similar to yesterday at near 80 with dew
points holding in the lower to mid 60s.

Low level convective support will be quite limited as the
prefrontal trough barely scrapes across our area and the lower
level flow becomes diffluent as the front reaches the Keys.
Meanwhile upper level jet support will remain well to our north.
As a result, despite high surface dew points, rain chances will
remain slim at best. Behind this front, winds will surge out of
the northwest to north, becoming windy. This front will inject
much cooler and drier across the Keys. Expect highs and lows to
slip 5 to 10 degrees below normal. The coolest lows will likely be
found in the lee of South Florida due to radiational cooling and
a South Florida land breeze. Dew points will plummet to near 50
Monday night and likely the 40s on Tuesday.

This will mark the beginning of a prolonged stretch of much
cooler than normal weather, lasting through the remainder of the
week. Highs will struggle to reach the upper 60s with lows falling
broadly in the 50s. These persistent cold temperatures will be a
consequence of the broad long wave trough remaining across the
CONUS as a series of shortwaves swing through the eastern United
States. In response, a couple of strong reinforcing surface highs
driving southward through the eastern United States will reinforce
the cool and dry air in place with additional northerly surges.
There is a possibility that medium and long range temperatures
may be cooler than forecast. This is due, in part, to the
strength and duration of the cold air advection episodes, and the
high likelihood that the shallow nearshore water temperatures will
fall well into the 50s. For now, will hold forecast temperatures
near the ensemble mean.

&&

.MARINE...
Issued at 1131 AM EST Mon Jan 26 2026
Small Craft Advisory conditions are expected as early as this
evening in the coastal waters as a cold front races in through
from the northwest. From synopsis, a strong cold front will push
through Keys coastal waters this afternoon through tonight. Winds
will start out light to gentle out of the southwest, strengthening
slightly through the day, as the tail end of a prefrontal trough
advances eastward across South Florida and the Keys. Expect winds
to freshen substantially as the front blasts through the Keys
marine zones, clocking around to the northwest to north and
becoming strong, gusting up to near 30 knots. Winds will relax
substantially on Tuesday, as high pressure builds southeastward
through the Southeast and across the Florida Peninsula. Additional
wind surges are becoming increasingly likely Tuesday night into
Wednesday night, as a reinforcing cold front rolls southward
across the area.

&&

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

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

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