Area Forecast Discussion
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FXUS62 KKEY 270235

Area Forecast Discussion
National Weather Service Key West FL
1035 PM EDT TUE JUL 26 2016

.DISCUSSION...A mean layer analysis reveals the subtropical ridge has
built west across the Florida Peninsula. This evening`s sounding
sampled the developing barotropic atmosphere, consisting of deep
easterlies and very little vertical wind shear. The low levels are
sufficiently moist, although dry layers invade above 850 mb. Based on
SPC`s sounding climatology for today, precipitable water is exactly
average, heralding a typical sounding for this time of year. Riding
along the southern flank of the subtropical ridge are undulations in
moisture and curvature, see loops of MIMIC TPW. One such undulation
is moving through the Straits as we speak. The KBYX radar detects
widely scattered showers and a few thunderstorms. East southeast
winds range from 12 to 19 knots, consistently highest at SANF1. The
gusts atop the Weather Service office have corroborated SANF1.
Temperatures are in the mid to upper 80s and dewpoints are in the mid
70s. The back side of this undulation will coincide with the typical
nocturnal surge associated with the cooling of the nearby larger
landmasses. We advertise a 40% chance of showers and storms which
seems reasonable. No changes planned nor needed.


.MARINE...Moderate to fresh, east to southeast breezes will prevail
on the coastal waters of the Florida Keys overnight through Thursday.
Winds will peak in the 15 to 20 knot range Wednesday and Wednesday
night, especially across the Straits of Florida and the western zones
of Hawk Channel. Small Craft Should Exercise Caution, and Small Craft
Advisories may be required.


.AVIATION...VFR conditions are expected to prevail at both the Key
West and Marathon terminals overnight and through Wednesday morning.
A shower or thunderstorms could impact either terminal, resulting in
brief MVFR or IFR conditions. However, there is not enough certainty
in the timing to warrant inclusion in the terminal forecast.
Therefore will keep vicinity showers for both terminals through the
TAF period. Surface winds will be easterly near 10 knots overnight,
increasing a few knots and becoming gusty after sunrise Wednesday.


.KEY Watches/Warnings/Advisories...


Data Collection......Chesser

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