Area Forecast Discussion
Issued by NWS Key West, FL

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343
FXUS62 KKEY 301738
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
138 PM EDT Thu Jul 30 2026

...New DISCUSSION, AVIATION...

.KEY MESSAGES...

- A reverse cloud line is possible this afternoon. Any developing
  cloud line will tend to favor waterspout development.

- Light to gentle southwest to west breezes expected today,
  becoming mainly light breezes tonight.

&&

.AVIATION...
(18Z TAFS)
Issued at 124 PM EDT Thu Jul 30 2026
VFR conditions will prevail throughout the period with SW winds
around 5 kts through this evening and becoming light/VRB overnight
into Friday. In addition, while isolated SHRA activity could occur
through this evening due to the development of a weak reverse
cloud line, any precip activity that does develop is expected to
be light enough with minimal aviation impacts.

&&

.PREV DISCUSSION...
Issued at 433 AM EDT Thu Jul 30 2026
The western periphery of the Atlantic ridge will continue to
extend west into the Keys for today. This will result in mainly
southwesterly flow, though, much weaker than previous days. Expect
mostly light to gentle southwest breezes today becoming light
tonight. While a generally quiet day is on tap for today, a
reverse cloud line is possible in the vicinity of the Island
Chain. We do have drier air in place, therefore, the cloud line
may struggle a bit. However, if it does develop, any cloud line
will tend to favor waterspout development. Outside of the cloud
line development, the heat will be the main concern with highs in
the lower 90s combined with dew points in the mid to upper 70s.
This will lead to heat index values pushing close to 108 degrees.
Overnight lows also won`t provide much relief in the lower to mid
80s.

The ridge over the Atlantic will retreat slightly for Friday
through the first half of the weekend. This will place the Keys
into a col region resulting in a potential period of light and
variable breezes. Moisture undulations will continue to rotate
around the ridge resulting in slight rain and thunder chances.
Also, expect continued typical summertime heat and humidity with
highs in the lower 90s and overnight lows in the lower to mid 80s.

As we head into Saturday night and the second half of the weekend,
the high will regain some control across the region resulting in
breezes freshening out of the southeast. Moisture will increase
slightly compared to previous days, though, still mostly remain
slight chances. However, there is a possibility these become
chance PoPs due to the increased moisture. It just depends on how
much more it increases across the area. Temperatures will be
slightly cooler with highs near 90 degrees and overnight lows in
the lower 80s.

There are signals for a potentially more active pattern to move
the Keys for the early to middle part of next week. Numerical
model guidance is beginning to signal a Tropical Upper Tropospheric
Trough (TUTT) cell lumbering into the Keys or nearby. Other model
guidance just shows an increase in moisture with an uptick in
rain chances. However, if the prior solution occurs, the potential
exists for feistier showers and thunderstorms as well as more
widespread. This would also come with some upper level support as
well. Right now, it is too far out to tell exactly the details of
what may occur. However, the one trend being picked up on is for
an increase in cloud cover, slightly cooler temperatures, and
increased rain chances through the period. The details for when
and how much, intensity of any activity remains all but highly
uncertain. Check back for updates as we continue to fine tune the
forecast.

&&

.MARINE...
Issued at 1037 AM EDT Thu Jul 30 2026
There are currently no watches, warnings, or advisories in effect
across the Florida Keys coastal waters. From synopsis, the
western periphery of an Atlantic surface ridge will continue to
slide westward across the Florida Keys coastal waters. This will
result in a weak nebulous flow through tonight with light to
gentle breezes. A col region will set up for Friday into the first
part of the weekend, resulting in a potential period of light and
variable breezes. As high pressure strengthens in the North
Atlantic, southeast breezes will freshen by the second half of the
weekend and into early next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  84  91  84  91 /   0  10   0  20
Marathon  83  90  83  90 /   0  10   0  20

&&

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

$$

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

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