-- Discussion containing changed information from previous version are highlighted. --
932
FXUS62 KKEY 201520
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
1120 AM EDT Thu Jun 20 2024

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

.DISCUSSION...
Issued at 1105 AM EDT Thu Jun 20 2024
Composite satellite imagery highlights broad cyclonic
(counterclockwise) flow engulfing the Florida Peninsula, including
the Florida Keys. At the surface, expansive high pressure centered
to the north of Bermuda is bridging two areas of low pressure: one
associated with Tropical Storm Alberto centered over eastern
Mexico, and another weak area of low pressure just to the east
of the Northern Bahamas. The relative locations of these features
has resulted in a slowly waning surface pressure gradient,
consistent with modestly slackened easterly breezes this morning.

The 12z sounding at KEY sampled quasi-steady geopotential heights
at virtually all sampled geopotential heights. The sounding also
revealed modest dry air intrusion in the 925-850 isobaric layer.
However, forced ascent from the aforementioned cyclonic features
has been able to overcome this dry air (at least south of the
island chain). For the rest of today, scattered, mainly light
passing showers and isolated thunderstorms will certainly be
possible. Undulations of dry and more moist air will likely
continue over the next 24 hours, as the surface low continues to
progress to the west northwest towards northern Florida. Middle of
the road PoPs (around 50%) seems appropriate based on this
scenario. Outside of canceling the Small Craft Advisory for
decreasing winds and subsiding seas, no additional changes
proposed to inherited forecast.

&&

.MARINE...
Issued at 1105 AM EDT Thu Jun 20 2024
Small Craft Should Exercise Caution headlines are posted for all
Florida Keys coastal waters. From synopsis, strong high pressure
centered north of Bermuda working in tandem with Tropical Storm
Alberto near the Bay of Campeche will result in moderate to fresh
breezes through this evening. A second, weak area of low pressure
currently east of the Bahamas will move west northwest, reaching
the southeast U.S by late this evening or overnight. This, along
with weakening Alberto over Mexico, will loosen the pressure
gradient, leading to slackening east to southeast breezes for
Friday through the first part of next week.

&&

.AVIATION...
(15Z TAFS)
Issued at 1105 AM EDT Thu Jun 20 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 from 20z onward. Near surface winds are
easterly at near 15 knots with gusts at times of up to 25 knots.

&&

.CLIMATE...
On this date in 1983, an F1 tornado produced $2.5m in damage near
Lower Sugarloaf Key. There were no tropical cyclones in the area.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  88  80  89  81 /  50  40  40  50
Marathon  88  81  89  82 /  50  30  40  50

&&

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

$$

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

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