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982
FXUS62 KKEY 200851
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
451 AM EDT Mon May 20 2024

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

.DISCUSSION...
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Issued at 451 AM EDT Mon May 20 2024

This morning has felt like summertime in terms of convection
across the Florida Keys. Mesoscale boundaries have been the main
trigger mechanism for convection, with multiple outflow boundaries
still present on radar. KBYX is currently detecting scattered
convection within the forecast area, with most of the storms
aligning with or being adjacent to the island chain. The strongest
activity is currently located near the Upper and Middle Keys.
Good upper- level support has been very evident across most of the
region, with radar derived hail hedging close to 2" inches in the
waters across the Bahamas and even in a storm that plowed through
the distant Straits earlier. The activity closer to home has not
been able to fire up as well until just recently, which may be due
in part to drier air in the mid- levels sampled by last night`s
00Z sounding. The storms that have been able to overcome this
drier air have been able to tap into the fat CAPE profiles and
have gone nuts. Panning out from the Keys, a trough is extending
across the western North Atlantic, dragging a frontal boundary in
its wake. This front has made it almost to Central Florida.

A good environment will remain in place for scattered showers and
isolated thunderstorms today. Winds will continue to shift to the
north ahead of the aforementioned frontal boundary, which will
continue to usher in lower dew points. Dew points have already
dropped roughly 3-5 degrees over the past few hours, which has
made quite an impressive difference in the level of comfort when
walking outdoors. These lowered dew points and temperatures will
keep the Keys below the threshold for Heat Advisories through the
remainder of the week. Winds will remain generally from the
northwest to north through Tuesday night, briefing becoming
variable on Tuesday. Decent moisture will remain in place through
Wednesday, which could help spur on mesoscale processes such as
cloud lines during this timeframe. Guidance has trended downwards
on the higher rain chances through Wednesday, so have capped PoPs
at 30%. Forecast rain chances may continue to decrease, depending
on how much dry air can invade into the mid-levels. Easterly flow
will return by mid-week as high pressure really builds back in,
which will allow for dew points to gradually rise back into the
mid 70s. As of now, MOS guidance does not hint at any of the
oppressive dew points we have been tormented with over the past
few days returning through the extended forecast luckily.
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&&

.MARINE...
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Issued at 451 AM EDT Mon May 20 2024

There are no watches, warnings, or advisories in effect for the
Florida Keys coastal waters. From synopsis, a frontal boundary
currently draped across north Central Florida has helped the wind
field across the Florida Keys become somewhat nebulous this
morning. Breezes have begun to shift to the west to northwest in
the western waters. By this afternoon, breezes will veer to the
northwest and increase. Tuesday through Wednesday, breezes will
gradually shift to the east as high pressure in the western North
Atlantic builds back in across the region.
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&&

.AVIATION...
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(06Z TAFS)
Issued at 451 AM EDT Mon May 20 2024

Widely scattered showers with a few isolated thunderstorms will wax
and wane in the vicinity of the island chain early this morning.
After sunrise, this activity will diminish with slight rain chances
persisting throughout the rest of the day. VCTS is included at both
terminals until we expect this activity to die down, though any
shower passing over a terminal may result in MVFR CIGs or VIS and
will be TEMPO`ed as needed. Near surface winds will start out light
of the southwest, becoming northwest at 5 to 10 knots this
afternoon.
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&&

.CLIMATE...
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On this day in 1932, the daily record rainfall of 3.83" was
recorded in Key West. Rainfall records date back to 1871.
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&&

.PRELIMINARY POINT TEMPS/POPS...
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Key West  90  79  89  79 /  20  30  30  30
Marathon  89  80  89  80 /  30  30  30  30
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&&

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

$$

Public/Marine/Fire...NB
Aviation/Nowcasts....JAM
Data Acquisition.....JAM

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