745 
FXUS62 KKEY 160909
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
409 AM EST Tue Feb 16 2021

.DISCUSSION...
.CURRENTLY...
Under partly cloudy skies and light south winds, temperatures are
averaging in the mid 70s along the island chain. Meanwhile, local
radars are detecting an area of scattered showers on the outer
waters of Mainland Monroe, with only isolated showers elsewhere.
On our marine district, winds are south to southwest at 10 to 15
knots. 

&&

.SHORT TERM...(Today through Thursday night)
A deep full-latitudinal long wave trough extending from the Upper
Great Plains southward into the extreme Southeast Gulf of Mexico
early this morning will lift northeastward, resulting in most of
the mid and upper level ascent remaining well north of our area.
However, a modest low level confluent flow combined with an
abundance of moisture will prompt a brief spell of well above
normal rain chances today, with moisture and low level convergence
becomes negligible later tonight. For Wednesday through Thursday
night, a deep western Atlantic anticyclone will build westward 
and over our region, resulting in 5 to 10 percent rain chances 
beginning Wednesday. The main temperature challenge will be over 
the Lower Keys this afternoon with the shallow cool front passing 
through. Given considerable low level stratus and gusty north 
winds, temperatures of around 80 degrees may fall into the mid to 
upper 70s during this afternoon with temperatures averaging in the
lower to mid 80s elsewhere. Temperatures will return to well 
above normal with an increasing southeast flow Wednesday through 
Thursday night.

&&

.LONG TERM...(Friday through Monday)
Another progressive long wave trough accompanied by a well
pronounced cold front will plow through the Southeast United 
States and Florida Peninsula Friday night, with much cooler and
drier air to filter into our area beginning Saturday. With that,
the best chance for an episode or two of rainfall will be with the
aforementioned boundary, with little if any measurable rainfall
expected for the balance of this time frame. Well above normal 
temperatures Friday will become about 5 degrees below normal 
Friday night through Saturday night, before moderating quickly 
thereafter.

&&

.MARINE...
A shallow cool front in the extreme Southeast Gulf of Mexico will
limp southeastward and clear at least the western half of our
marine district, before becoming stationary on our far eastern
waters late this afternoon and early evening. With that, a Small
Craft Should Exercise Caution for increasing winds will be
inserted for the western half of our coastal water this afternoon
and early evening. Beyond that, the boundary will lift
northwestward and into the Southeast Gulf of Mexico and the
Florida Peninsula on Wednesday. Thereafter, a strong cold front is
expected to pass through our entire marine district late Friday,
with strong northerly breezes to follow through at least Saturday
night. 

&&

.AVIATION...
Scattered showers and a possible thunderstorm are expected to affect 
the Florida Keys this morning and early afternoon ahead of a cold 
front, with the main core likely moving through between 14Z and 19Z. 
These squalls are expected to produce MVFR conditions, although the 
ceilings may drop to IFR in the late morning and early afternoon. 
The weather will dry out behind the cold front this afternoon. Winds 
S-SW near 10 knots, becoming NW-N at 10 to 15 knots with occasional 
gusts near 20 knots this afternoon. 

&&

.CLIMATE...
In 1991, the daily record low temperature of 53 degrees was 
recorded in Key West. Temperature records date back to 1872.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  79  71  81  75 / 70 30 10 10 
Marathon  81  72  83  75 / 60 30 10 -  

&&

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

$$

Public/Marine/Fire...APA
Aviation/Nowcasts....SDR

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