Area Forecast Discussion
Issued by NWS Key West, FL

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870
FXUS62 KKEY 211447
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
1047 AM EDT Fri Jun 21 2024

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

.DISCUSSION...
Issued at 1045 AM EDT Fri Jun 21 2024
Composite vorticity analysis places an area of low pressure
centered just east of the Florida First Coast from the surface up
to around 500 mb, and another broad area of low pressure centered
in the western Gulf of Mexico. These features are interacting with
broad high pressure centered north of Bermuda to produce a net
east to southeast steering flow. Dry air sampled in last evening`s
sounding up to around 750 mb has been largely eradicated, as the
aforementioned low pressure features advect deep, tropical
moisture in from the southeast towards the Keys.

KBYX and KAMX Doppler radar`s have been detecting minimal shower
activity thus far this morning, although this is expected to
change over the next several hours. An uncapped tropospheric
profile sampled this morning at KEY, along with no inhibition and
increased boundary layer moisture, will support proliferation of
scattered showers and thunderstorms by late this afternoon or
evening. Available convective allowing model (CAM) guidance
supports this meteorological reasoning, although there remains a
bit of uncertainty in timing of convective triggering. Bouts of
broken sunshine should allow temperatures to reach the upper 80s
during peak heating. No changes proposed to the inherited short-
term forecast.

&&

.MARINE...
Issued at 1045 AM EDT Fri Jun 21 2024
There are currently no watches, warnings, or advisories in effect
across the Florida Keys coastal waters. Although Florida Keys
marine zones are generally dry for now, scattered showers and
thunderstorms are expected to develop by late this afternoon or
this evening. Any stronger thunderstorm will have the potential to
produce blinding downpours, gusty winds and confused seas, and
cloud to surface lightning strikes. From synopsis, interaction
among low pressure off the east coast of Florida, high pressure
centered north of Bermuda, and broad low pressure in the vicinity
of the Yucatan Peninsula will result in gentle to moderate east to
southeast breezes over the next few days. Moisture pulled into
our area via the low to the west will result in waves of unsettled
weather this weekend. High pressure building over the North
Atlantic early next week will result in light to gentle southeast
to south breezes and a return to near- normal rain and thunder
chances.

&&

.AVIATION...
(15Z TAFS)
Issued at 1045 AM EDT Fri Jun 21 2024
VFR conditions will prevail at both EYW and MTH through the TAF
period. Shower activity will return later this afternoon into the
evening so VCSH is included. Near surface winds are easterly at near
10 knots.

&&

.CLIMATE...
In 1986, an F1 tornado caused $250k in damage between Plantation
and Tavernier. Tropical Storm Bonnie formed two days later on the
23rd in the central Gulf of Mexico moving westward, so this
tornado may have been caused by the initial depression/circulation.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  79  88  79  88 /  50  50  50  50
Marathon  80  88  80  88 /  50  50  50  50

&&

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

$$

Public/Marine/Fire...BT
Aviation/Nowcasts....AP
Data Acquisition.....AP

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