Area Forecast Discussion
Issued by NWS Key West, FL

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FXUS62 KKEY 270918

Area Forecast Discussion
National Weather Service Key West FL
418 AM EST Sat Feb 27 2021

Nighttime microphysics is showing very little in the way of cloud
cover except some shallow cumulus moving in from the southeast.
KBYX has remained echo-free overnight thanks to an area of high
pressure off the northeast coast causing large scale subsidence
over our region. The 00Z KEY RAOB also showed very dry air above
750 mb. Temperatures across the island chain have only dropped as
low as the mid to upper 70s due to the warm east-southeast flow.
This has also kept the dewpoints near 70 degrees. Winds have
picked up since yesterday, with our marine locations observing
15-18 knots across our waters.

The previously mentioned area of high pressure moved off the northeast
coast into the Western Atlantic last night. The gradient has
tightened due to the surface high starting to build to the south,
which has allowed our winds to increase. Breezy conditions are
expected to last until around Sunday before starting to taper off
Sunday night as the anticyclone moves more eastward. We will
remain under the influence of this high pressure into mid-week,
with east to southeast winds prevailing and above normal
temperatures expected. Rain chances will also remain near nil
until then.

There is still a large discrepancy in the models regarding next
week and whether or not the Florida Keys will get a late season
cold front, as well as the strength of it if it does arrive. MOS
guidance is currently showing differences of up to three standard
deviations for temperatures heading into next weekend. The
ensemble plumes are also showing a great deal of uncertainty as we
get into the latter half of next week. Due to the large spread in
guidance, have opted to not stray too far from previous forecast
in the long-term. Refinement of the details of the forecast will
occur with the next few forecast cycles. Stay tuned..


Small craft should exercise caution in all waters except for the
Gulf Waters. Small Craft advisories likely will be required for
the Hawk Channel and the Florida Straits tonight. From synopsis, A
dominant dome of high pressure located off the northeast coast
will slide east during the day today. As the high slides east, it
will build south, leading to freshening breezes. Fresh east to
southeast breezes are expected today through Sunday night, with
the strongest winds tonight. Breezes are expected to subside and
become gentle to moderate Monday through Tuesday. Light to gentle
breezes will prevail throughout the day on Wednesday.


VFR conditions are expected to prevail at EYW and MTH through the
TAF period, with few to scattered cloud bases FL020-025. No rain is
expected, and surface winds will be east to southeast 11 to 15 knots
with frequent gusts near 20 knots.


On this day in 1989, the daily record low temperature of 46F was
recorded. Temperature records in Key West date back to 1872.





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