395
FXUS62 KKEY 160225
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
1025 PM EDT Mon Jul 15 2024

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

.DISCUSSION...
Issued at 1025 PM EDT Mon Jul 15 2024

Scattered showers and isolated thunderstorms have waxed and waned
a few times across various parts of the Keys coastal waters during
the late afternoon and evening hours, however the island chain has
remained dry. Currently, radars show the greatest concentration of
activity over the waters between Andros Island and the eastern
Florida Straits, with little activity closer to the Keys.
Temperatures along the Keys are slowly dropping into the mid 80s,
with dewpoints in the mid to upper 70s, and winds on land from the
east to southeast around 10 mph. Surface analysis depicts a
typical July pattern, with a dominant Atlantic ridge extending
westward across the Florida peninsula into the Gulf of Mexico, and
a weak tropical wave moving inland into Central America. Aloft,
the subtropical ridge axis also extends from the Atlantic westward
across Florida, with deep easterly flow over the Keys to the
south of the ridge. The 00Z Key West sounding sampled a moist and
conditionally unstable airmass, with PW of 2.23 inches (above the
90th percentile for the date). MIMIC-TPW satellite imagery shows a
similarly moist airmass with estimated PWs of 2 inches or greater
extending eastward from the Keys to Andros Island. A much drier
airmass, with estimated PWs near 1.5 inches or less, extends from
Andros Island eastward for several hundred miles.

Overnight, the moist airmass as sampled by the 00Z sounding will
remain over our area, providing plenty of fuel for any convection
that develops. However, whether we will see a trigger for
development is uncertain, especially given the current lack of
nearby activity on radar. An expected slight increase in ESE low
level flow later tonight could provide the necessary kick to spark
more activity near the Keys, although most of the CAM guidance
remains rather dry through the night. All of the above said, it is
difficult to lower overnight rain chances with so much moisture
available, especially in this ESE flow pattern that often favors
increased late night activity after relatively quiet evenings.
Will leave the existing 40 percent PoPs unchanged. Otherwise,
expect a typically warm and muggy night, with overnight lows in
the lower 80s and dewpoints holding in the mid to upper 70s.

&&

.MARINE...
Issued at 1025 PM EDT Mon Jul 15 2024

Evening observations show ESE breezes holding around 10 knots
along the reef and at Long Key C-MAN, with seas at Satan Shoal
running around 1.5 feet. Winds may still increase a notch during
the next few hours into the 10 to 15 knot range. From the
synopsis, Atlantic ridging will remain across the Florida
Peninsula through the duration of the forecast. This will result
in gentle to moderate easterly to southeasterly breezes across
Keys waters. Winds will tend to surge in the evening and night
hours and lull during the day.

&&

.AVIATION...
(00Z TAFS)
Issued at 1025 PM EDT Mon Jul 15 2024

VFR conditions will prevail through Tuesday at the EYW and MTH
terminals. Convection may increase near the terminals late
tonight, and have included VCSH after 03Z. Short-term amendments
for any possible sub-VFR impacts at the terminals will be based
primarily on radar trends. Surface winds will remain from the east
to southeast at 7 to 10 knots.

&&

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

$$

Public/Marine/Fire...Jacobson
Aviation/Nowcasts....Jacobson
Data Acquisition.....DR

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