Area Forecast Discussion
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FXUS62 KKEY 300236

Area Forecast Discussion
National Weather Service Key West FL
1036 PM EDT THU SEP 29 2016

.DISCUSSION...A cutoff upper level low spins across the Ohio River
valley and stretches south into the Gulf of Mexico. The mean layered
700-850 mb analysis from CIMSS retains the subtropical ridge west-
southwest across the central Bahamas. At the surface, a frontal
boundary lags to the southwest through the Florida panhandle from a
surface low nestled east of the Appalachians. Surface observations
indicate weak ridging persists through the Bahamas and across the
Florida Keys. Winds are light and variable beneath mostly cloudy
skies. Aside from scattered showers and storms which have persisted
west of the Tortugas much of the evening, the KBYX radar is sans
echoes nearby the island chain. Temperatures are near 80 degrees with
dewpoints in the mid 70s.

.FORECAST...The 00Z KKEY RAOB sampled a little more moisture compared
to the last few soundings. It appears the dry slot apparent on MIMIC
TPW imagery has retrograded to the east-southeast into the Straits of
Florida. The profile is moderately unstable, with weak inhibition
below 850 mb. The 500 mb temperature is -8.7 degC, which is two
degrees cooler than 24-hours ago.

The weak and variable wind profile will become easterly overnight,
driving the dry slot (see MIMIC) back to the west across the Florida
Keys. Remnant boundaries in the southeastern Gulf of Mexico should
become foci for convective initiation once the easterlies converge.
Thus, we increased shower and thunderstorms coverage across the
extreme western zones. Otherwise, no changes planned for the
inherited forecast.


.MARINE...No watches, warnings, or advisories are in effect, and the
forecasts contain no headlines. A weak pressure pattern will persist
across the Florida Keys and adjacent coastal waters tonight and
Friday, resulting in light to occasionally gentle breezes. Breezes
will freshen Saturday through Monday.


.AVIATION...VFR conditions will prevail at both the Key West and
Marathon terminals overnight and through Friday morning. Surface
winds will be variable less than 5 knots overnight, becoming easterly
near 5 knots Friday morning.


Key West  80  89  79  88 / 20 30 30 40
Marathon  78  90  79  89 / 20 30 30 40


.KEY Watches/Warnings/Advisories...


Data Collection......Vickery

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