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000
FXUS62 KKEY 221912
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
312 PM EDT Mon Apr 22 2024

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

.DISCUSSION...
Issued at 300 PM EDT Mon Apr 22 2024
Light, southwesterly flow late this morning allowed a broken
reverse cloud line to form along portions of the island chain.
This interacted with some pre-frontal shower activity to produce a
few isolated showers in the vicinity of Marathon earlier this
afternoon, with 0.02" of observed rainfall measured at Marathon
International Airport. This activity has since waned, with KAMX
Doppler radar only detecting scattered showers and thunderstorms
over the favored South Florida Mainland. Temperatures are
generally in the lower 80s across the island chain at this mid-
afternoon hour.

For tonight, we will need to monitor the progress of the activity
over South Florida. This may trigger outflow boundaries that could
clip portions of the Upper Keys and the adjacent coastal waters.
Most convective-allowing model (CAM) guidance supports this
evolution, with most of this (albeit isolated to scattered) taking
place between 00z-05z. The Lower and Middle Keys are expected to
remain generally dry tonight.

High pressure will build in the wake of this weak frontal boundary
across the Southeast, then quickly slide eastward into the western
North Atlantic. For the Florida Keys, the result will be winds
quickly clocking around to the easterly direction and thus very
minimal cool advection. Forecast soundings suggest a very dry
lower tropospheric profile for the work week and into next
weekend. With a weak mid-level ridge in place over the Gulf of
Mexico, this will act to deflect any major synoptic disturbances.
Inherited a dry forecast through Sunday, and this still seems
appropriate after digesting the latest numerical weather
prediction guidance today. Near-normal temperatures will continue
through next weekend, with highs generally in the lower to mid
80s, and lows in the lower to mid 70s.

&&

.MARINE...
Issued at 300 PM EDT Mon Apr 22 2024
Small Craft Should Exercise Caution headlines for increasing
winds are posted for all Florida Keys coastal waters. In addition,
Small Craft Advisories may be required for some marine zones late
in the overnight hours. A weak front will continue to move
through the Florida Keys coastal waters this evening, with light
to gentle west to northwest breezes slowly freshening. Fresh to
strong breezes will clock around to the northeast before sunrise,
with moderate northeast to east breezes prevailing from late
Tuesday night through Thursday. Strengthening high pressure over
the western North Atlantic will produce fresh to strong easterly
breezes to the Keys marine zones beginning Friday, lasting through
much of next weekend. Small Craft Advisories may be required for
portions or all of the Florida Keys marine zones for these
periods.

&&

.AVIATION...
(18Z TAFS)
Issued at 300 PM EDT Mon Apr 22 2024
Westerly winds will persist over EYW and MTH through the afternoon,
but a decayed cold front will veer winds to northwesterly in the
evening and northeasterly overnight. Brief periods of MVFR CIGS are
possible along wind shift lines, but otherwise VFR CIGs will prevail
at both terminals. Expect a further east-northeasterly shift by
tomorrow morning.

&&

.CLIMATE...
On this day in 1940, the daily record low temperature of 62F was
recorded in Key West. Temperature records for Key West date back to
1872.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  73  82  74  83 /  10  10  10  10
Marathon  73  83  75  82 /  10  10  10  10

&&

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

$$

Public/Marine/Fire...BT
Aviation/Nowcasts....AJP
Data Acquisition.....JAM

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