Area Forecast Discussion
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FXUS62 KKEY 230049

Area Forecast Discussion
National Weather Service Key West FL
849 PM EDT Mon May 22 2017

.DISCUSSION...In the middle and upper levels(700-200 mb), latest
available IR imagery overlaid with model streamline analysis as of
800 pm, depict a burgeoning full latitude trough that extends
south to Northern Texas from low pressure over Northern Minnesota
and Ontario. A series of shortwaves continues to dig this trough
deeper. A nearly 100 knots jet at 250 mb over Central Texas
decelerates quickly upon reaching the Eastern Gulf of Mexico and
Florida where it encounters middle and upper ridging

At the surface and in the lower to middle levels,(Surface to 700
mb), latest IR imagery overlaid with land and marine surface
observations and analysis as of 800 pm, detail weaker broad
ridging from the Upper Ohio Valley southwest to Louisiana. A
weaker frontal boundary is nearly stationary from East Tennessee
southwest to the Texas Coast. The Keys are south of the western
periphery of a surface ridge that moves across the Florida
Peninsula. As a result, the 00Z sounding illustrated a gentle SE
flow from the surface to 850 mb, slowly veering to west up to
about 300 mb. Total PWAT in the column was only 1.26 inches.

.CURRENTLY...As of 800 pm, skies are mostly clear across the
islands and all surrounding waters. Temperatures across the
islands are in the lower 80s with dewpoints in the lower 70s.
C-man stations along the Florida Reef are recording southeast
winds between 10 and 15 knots, and island platforms recording
southeast winds near 10 mph.

.SHORT TERM...Overnight, another impulse over the Rockies will
dive southeast, continuing to carve out the aforementioned trough
over the Central CONUS. Locally, the combination of weak low
pressure developing along the frontal boundary, near the
Louisiana Coast, and a ridge axis remaining to the north of the
Keys, will result in gentle to occasionally moderate southeast to
south breezes overnight. Latest model forecast soundings do
illustrate some low level moistening between 0600-1200Z, with PWAT
rising up to near 1.5 inches by 12Z, but middle level subsidence
would be quite prohibitive to shower development. Nevertheless,
will maintain a dime pop already in the grids for the overnight


.MARINE...Overnight, No headlines or advisories. Gentle to
moderate breezes are expected across the waters, with a slight
surge, near 15 knots expected across Hawk Channel and the Florida
Straits towards daybreak.


.AVIATION...Rest of tonight, VFR conditions expected at both the
KEYW & KMTH Int`l island terminals. Expect some scattered clouds
at FL020-025.




Upper Air/Data Collection......Vickery

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