874
FXUS62 KKEY 120908
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
508 AM EDT Mon Aug 12 2024

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

.DISCUSSION...
Issued at 505 AM EDT Mon Aug 12 2024
It seems like another repeat of yesterday across the Florida Keys
this morning. A spattering of showers is percolating and drifting
west through the Straits of Florida and nearshore waters of the
island chain. Despite modest coverage noted on KBYX radar, most
convection has kept clear of land leaving current temperatures
once again in the mid 80s and dewpoints in the upper 70s. A
persisting Atlantic low level ridge across the Florida Peninsula
continues to promote gentle easterly breezes along the Reef.

Not much change in sensible weather is on tap for today. The main
headline is once again the issuance of a Heat Advisory for the
Keys from later this morning into the evening hours. Forecast
highs in the lower 90s paired with dewpoints in the upper 70s will
result in heat index values up to 110 degrees. The good news is
that there is enough moisture in the air for a few showers to
possibly cross the island chain today bringing some relief to the
heat. However a lack of organized lift will leave their coverage
scattered at best, with PoPs remaining near normal for this time
of year.

Tonight, a Saharan Air Layer (SAL) plume will slide over our area
from the east. This airmass is currently observed over the
Bahamas via CIMSS MIMIC TPW. Model soundings for later tonight and
into tomorrow morning show a stark drying of the lower to mid
levels as this feature crosses through. As a result, PoPs have
been lowered to a slight chance for tonight and to a lower end
chance for Tuesday as the moisture plume behind it no longer seems
as potent as in previous guidance.

In the extended forecast, a deep layer trough will establish
itself along the East Coast by the middle of the week. As this
trough slides south down the Eastern Seaboard, the Atlantic ridge
over mainland Florida will recede east. This will result in
lighter and more variable winds across our CWA by Thursday
evening. Northerly winds will then take over as PTC 5 passes far
to the east of Florida this weekend.

&&

.MARINE...
Issued at 505 AM EDT Mon Aug 12 2024
No watches, warnings, or advisories are in effect for the Florida
Keys coastal waters. From synopsis, an Atlantic ridge axis
planted north of the Keys coastal waters will promote gentle to
moderate easterly breezes through the early part of this week.
Breezes will then slacken and veer to the northwest by Thursday
night as a trough dips south along the Eastern Seaboard. As a
result, breezes will then become more chaotic by Friday as the
ridge axis fractures over Florida. A tropical disturbance to the
east of the Bahamas will move north towards Bermuda Friday and
Friday night.

&&

.AVIATION...
(06Z TAFS)
Issued at 505 AM EDT Mon Aug 12 2024
Isolated showers dotting the forecast area may near both terminals
through the mid to late morning, so have maintained VCSH. Later this
afternoon/evening, a much drier airmass will lead to minimal shower
coverage. Surface winds will be from the east to southeast at 5 to
10 knots.

&&

.CLIMATE...
On this day in 1926, the daily record low temperature of 71F and the
daily record rainfall of 2.59" were both recorded in Key West.
Temperature records date back to 1872 and rainfall records date back
to 1871.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  92  83  92  84 /  30  20  30  30
Marathon  92  84  93  84 /  30  20  30  30

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory from 10 AM this morning to 7 PM EDT this evening
     for FLZ076>078.

GM...None.
&&

$$

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

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