Area Forecast Discussion
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FXUS62 KKEY 221859

Area Forecast Discussion
National Weather Service Key West FL
259 PM EDT Sat Oct 22 2016

Changes to Forecast -- No significant changes were made; only slight
adjustments to the digital forecast database.

Current Situation and Analysis -- The first true autumn cold front
cleared the service area this morning, with air temperatures in
most Keys island communities remaining near or just below 80F, with
dewpoint temperatures dropping all day, currently approaching 60F
most locations.  Local Doppler radar scans are void of precipitation
echoes across the service area, while satellite and surface
observations show mostly clear skies across the Keys, and some
scattered stratocumulus clouds pulling away over the Straits of
Florida.  Fresh north to northeast breezes have been blowing west
of the Seven Mile Bridge, while winds have been much lighter to the

Prognostic Overview -- We hoisted Small Craft Advisories earlier
for the coastal waters west of the Seven Mile Bridge, based on
observational trends.  Forecast reasoning has not changed
appreciably from the last cycle.  A large area of continental
high pressure will govern the weather pattern for the next few
days.  Low-level cold thermal advection will peak overnight, with
the coolest and driest air likely since early May.  Thereafter,
gradual, but slow, air mass modification will ensue, while gradient
flow remains robust, and likely increasing later in the week.  In
fact, models indicate both increasing MSL pressure to the north of
the area, and decreasing MSL pressure to the south, resulting in
increasingly likely periods of strong breezes through mid to late
week.  Rain chances start out nil, then increase gradually, with
even some thunder possible as the surface air reaches near
maritime tropical again by Thursday.

A Small Craft Advisory is in effect for the coastal waters west of
the Seven Mile Bridge.  Small craft caution headlines cover the
other zones.  A large area of high pressure over the southeastern
United States will generate fresh to strong north to northeast
breezes from tonight through thursday.

In the wake of the frontal passage this morning, gusty northerly
breezes have persisted across both island terminals today, with just
a few clouds AOA FL025. Winds will veer out of the northeast by
Sunday morning, becoming gusty once again after 23/12z. With rain
chances remaining near zero, VFR VIS/CIG`s highlight the forecast.

The last time temperatures in Key West dipped below 70F dates back
to May the 8th 2016, some 167 days ago. The average date for such
an occurrence is October 28th. Temperature records in Key West date
back to 1872.

Key West  71  80  72  81 / -  0 -  -
Marathon  70  80  72  81 / -  0 -  -

GM...Small Craft Advisory in effect for GMZ033-GMZ034-GMZ035-


Data Collection......Fling/Vickery

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