Area Forecast Discussion
Issued by NWS Key West, FL

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000
FXUS62 KKEY 280813
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
413 AM EDT Tue Jun 28 2022

.DISCUSSION...
Quiet conditions prevail along the Florida Keys on this early
Tuesday morning, with radar showing isolated showers moving slowly
northwest across the area. Southeast breezes around 10 mph are
holding temperatures in the lower 80s at most island locations.
Surface analysis depicts a weak trough over the SE Gulf of Mexico,
with a front along the Eastern Seaboard and across the
Southeastern states, and weak high pressure displaced eastward
over the western Atlantic. Aloft, water vapor imagery shows a
well-defined upper trough over the northwestern Bahamas and
eastern Florida Straits, with a mid latitude trough moving off the
Mid Atlantic and Northeast coast. As a result, the subtropical
ridge is fragmented and weaker than normal for the end of June.
The 00Z Key West and Miami soundings sampled some relatively dry
air between 950 and 850 mb, which apparently was sufficient to
suppress convection on Monday, as activity was quite a bit less
extensive along the Keys than would be expected with the nearby
upper trough and near normal PW values.

For today, the question is whether the low level dryness, which
is forecast to persist, will once again suppress activity that
would otherwise be expected to flourish given the nearby upper
trough. The expected mesoscale setup is not especially favorable
either, with gentle SE flow not really allowing for migration of
convection/outflows from the adjacent larger landmasses, nor for
island cloud line development. The CAM guidance is mixed. Have
nudged PoPs down slightly to 30 percent for today, which is near
the MOS consensus. Little change is expected through Thursday,
with gentle E/SE flow, near normal moisture, and the upper trough
lingering nearby. Have continued with slightly above climo PoPs of
30 percent.

More typical mid summer weather should finally develop late this
week and continue through the weekend, as surface high pressure
and a ridge aloft build across the Southeastern states. This will
bring increasing E/SE flow across the Keys. However, PWs are
forecast to remain near to slightly above normal, and with at
least remnants of the upper trough forecast to linger nearby,
will maintain slightly above climo 30 percent PoPs through the
period.

&&

.MARINE...
There are no watches, warnings, or advisories currently in effect
for the coastal waters of the Florida Keys. Gentle east to
southeast breezes will continue across the Keys coastal waters
through Thursday morning, as weak high pressure remains over the
western Atlantic. Easterly breezes will freshen from late Thursday
into the weekend, with nighttime surges and daytime lulls, as
high pressure builds westward into the Southeastern United States.

&&

.AVIATION...
VFR conditions will prevail at EYW and MTH through the TAF
period. A few nocturnal showers this morning may pass over the
terminals, but confidence is too low in timing and location to
include any mention of VCSH at this time. Surface winds will be
out of the southeast at 6 to 9 knots.

&&

.CLIMATE...
On this day in 1909, the daily record rainfall of 3.87" was recorded
in Key West. Rainfall records for June date back to 1871.

&&

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

$$

Public/Marine/Fire...Jacobson
Aviation/Nowcasts....NB

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