Area Forecast Discussion
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FXUS62 KKEY 270902

Area Forecast Discussion
National Weather Service Key West FL
502 AM EDT Sat May 27 2017

Mainly zonal flow aloft sits atop a weak and diffuse surface
pressure gradient. MIMIC TPW products highlight the band of pooled
moisture stretching across the Bahamas, the Florida Straits, and
the southern Gulf of Mexico. Shortly after midnight, a classic
`ghost-line` erupted near the upper Keys, then proceeded to
zipper down the coastal waters adjacent to the middle and lower
Keys. The most recent scans indicate the col-region of convergence
persists across the Straits, with scattered showers and isolated
thunderstorms flourishing within a moist and unstable boundary
layer. Temperatures across the island chain are near 80 with
dewpoints a couple of degrees below that. A humid, sticky early
morning, with flashes of lightning painting the southern sky.

A formidable mean layer ridge will develop over the Gulf of
Mexico today through Sunday. The surface ridge will remain
fractured and split across the Florida Peninsula. As the
anticyclone develops to our north, warm and dry air will invade
the lower and middle troposphere. Thus, mainly variable winds,
with hot days and muggy nights. Rain chances will be nearly nil,
with one exception, the Straits tonight. Lingering boundaries
should activate tonight well to the south of the island chain. The
mean layer ridge will drift eastward Monday through Tuesday,
consolidating the western flank of the Atlantic ridge. Boundary
layer moisture will slowly increase as east to southeast breezes
freshen. Moist convection will remain challenged due to the
entrenched compression aloft. Significant rain chances do not
return until Thursday or Friday as the mean layer ridge erodes,
allowing moist parcels free reign with the deep, maritime-
tropical atmosphere.


No current watches, warnings, or advisories. A feeble ridge of
high pressure will extend across the Florida Peninsula today
through Sunday. This ridge will strengthen Sunday night through
Wednesday resulting in freshening east to southeast breezes.


VFR conditions are expected at the island terminals today.
Surface winds will be weak, ranging from northeast to variable.




Data Collection......Vickery

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