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430
FXUS62 KKEY 242302
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
702 PM EDT Tue Sep 24 2024

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

.DISCUSSION...
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Issued at 619 PM EDT Tue Sep 24 2024

Currently - All eyes are fixed on Tropical Storm Helene as it
continues to organize as it slowly moves northwestward through the
northwestern Caribbean Sea. The Keys are already falling within
the far northern periphery of Helene`s cyclonic envelope and
local winds have come up to near breezy across the Keys. In
addition, multiple convective bands have been driving
northwestward across our area, occasionally giving portions of the
island chain a quick torrential dousing and wind gusts of 35 to
40 mph.

Helene is a rather large system that is expected to continue
gather strength over the next couple of days. Helene is expected
to move northwestward tonight, then northward tomorrow, and
eventually north northeastward towards Florida on Thursday. A
brief close brush with the Yucatan and initially modest shear is
not expected to deter Helen`s intensification as Helene is
expected to move into an environment with very warm waters, low
shear, and healthy upper level diffluence. Helene is expected to
become a major hurricane by Thursday afternoon as it moves into
the eastern Gulf of Mexico. While all guidance points to a
passage northward well west of the Florida Keys, we should fall
within Helene`s tropical storm wind radii. As a result, a
Tropical Storm Warning is now in effect for the Middle and Lower
Keys. Expect occasional rounds of showers and a few thunderstorms
throughout the Keys. Winds will peak as Helene makes its closest
approach early Thursday. Helene`s strong winds is expected to
drive 1 to 3 feet of storm surge flooding, particularly in low
lying flood prone areas along our southern shores.

As Helene pulls further away and winds down over the southeastern
United States, Atlantic ridging will pivot northward out of Cuba
and into the Keys area. As a result, expect a fairly quick
wind field collapse heading into the weekend with rain chances
falling to near normal. Unfortunately Helene`s passage will have
pulled deep tropical moisture across the Keys. Expect hot and
humid conditions.
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&&

.MARINE...
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Issued at 619 PM EDT Tue Sep 24 2024

Large Tropical Storm Helene is expected to strengthen as it moves
northwestward through the northwestern Caribbean Sea. Helene will
gradually arc north then north northeastward over the next couple
of days. As a result of Helene`s size and forecast track, a
Tropical Storm Warning remains in effect for a sizable portion of
Keys waters. Expect the strongest winds and highest seas around
the period of closest approach early Thursday.
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&&

.AVIATION...
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(18Z TAFS)
Issued at 619 PM EDT Tue Sep 24 2024

Squalls will continue to increase in coverage over the next 24 hours
as Tropical Storm Helene starts to trek north. Ahead of the main
event (likely Wednesday evening through Thursday afternoon),
occasional squalls will pass over the terminals tonight which will
likely require continued use of TEMPOs. Surface winds will slowly
increase overnight, with southeasterly gusts of 20 to 25 knots
expected at MTH and gusts near 25 knots at EYW by early tomorrow
morning. Winds will only continue to increase thereafter. Conditions
will deteriorate by tomorrow afternoon, with fast-moving squalls
capable of gusts near 45 knots and MVFR to IFR conditions likely.
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&&

.KEY WATCHES/WARNINGS/ADVISORIES...
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FL...Coastal Flood Warning until 6 PM EDT Thursday for FLZ076>078.
     Tropical Storm Warning for FLZ077-078.
GM...Tropical Storm Warning for GMZ032>035-043-044-053>055-073>075.
     Small Craft Advisory for GMZ031-042-052-072.
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&&

$$

Coordinator/Hazards..BT
Public/Marine/Fire...11
Aviation/Nowcasts....JAM/NB
Social Media.........LIW
Data Acquisition.....DR

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