Area Forecast Discussion
Issued by NWS
FXUS62 KKEY 271836
Area Forecast Discussion
National Weather Service Key West FL
236 PM EDT Mon Mar 27 2017
.DISCUSSION...In the middle to upper level(700-200 mb), latest
available model streamline analysis overlaid on top of satelitte
imagery as of 200 pm depict a zonal/broadly cyclonic middle and
upper level pattern across the entire CONUS. The axis of two
shortwaves embedded within the flow are evident, with one
approaching the Middle Mississippi Valley down to Louisiana, and
a second now upstream approaching the Bitteroots. But the flow is
mainly zonal upstream of the Keys over the Gulf.
At the surface and in the lower to middle levels(Surface to 700
mb), Latest satelitte imagery overlaid with marine and land
surface observations and analysis as of 200 pm, details the center
of 1025 mb center of surface ridging near 37 North 60 West. Well
to the south of that feature, a developing 1007 mb gale center is
near 25 North 69 West. The combination of these two features is
allowing for only gentle to moderate easterlies across the islands
and surrounding waters, with some gusts over 15 knots attm.
.CURRENTLY...As of 200 pm, Skies are mostly sunny across the
islands and surrounding waters. Radar does detect a few very light
showers dotting waters 25 nm offshore of the Keys Island Chain.
Temperatures are near 80 degrees across the islands, with
dewpoints in the middle to upper 60s. C-man stations along the
Florida Reef, Florida Bay, and Smith Shoal Light are northeast to
east at 10 to 15 knots, except closer to 15 knots at Pulaski Shoal
and Sand Key Light.
.SHORT TERM...Tonight thru Thursday Night, a period of Mostly
Sunny skies with chamber of commerce weather and no rainfall can
be expected over the islands. As the aforementioned gale over the
South Atlantic moves northwards away from Dominican Republic,
dominant surface ridging sets up over the Florida Peninsula
allowing for gentle to moderate breezes across the waters. Very
fry air will continue to be advected across the islands in the
middle level zonal flow. And latest available forecast soundings
keep PWAT well under an inch over the islands. Temperatures, given
strong insolation and weak mixing, will reach into the middle
80s starting Tuesday, with lows in the lower 70s. Across the
Outer Florida Straits waters, only a few light showers given weak
convergence can be expected.
.LONG TERM...Friday through Monday, a weak surface trough, shear
axis is progged to approach across the Gulf waters. The net affect
will be for winds to veer more to between southeast and South from
Friday and Friday night, but the system appears to weak and
dissolves near the Keys Saturday and Saturday Night. Another weak
ridge may build in across the Peninsula for Sunday thru Monday.
Daytime Temperatures will continue to reach the mid 80s, with
overnight lows only falling down to the low to mid 70s.
.MARINE...Winds will be gentle to moderate form east to southeast. No
cautionary or advisory headlines for small craft are expected
VFR conditions will prevail at EYW and MTH this afternoon through at
least Tuesday morning. Sustained northeast to east winds of 15 to 20
knots from just off the surface to about 3,000 feet will decrease to
10 to 15 knots this evening.
On this date in Florida Keys weather history, in 2013, the low
temperature at Key West International Airport was 57 degrees. This
set the daily record for minimum temperature measured in Key West on
March 27th. Temperature records at Key West date back to 1872.
.PRELIMINARY POINT TEMPS/POPS...
Key West 72 84 72 84 / - - - -
Marathon 72 85 71 85 / - - - -
Upper Air/Data Collection......Vickery
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