Area Forecast Discussion
Issued by NWS

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FXUS62 KKEY 181920

Area Forecast Discussion
National Weather Service Key West FL
Issued by National Weather Service JACKSONVILLE FL
220 PM EST Mon Dec 18 2017

Currently - An upper level ridge is centered over Cuba and the
Florida Straits with the surface ridge centered east-west over
central Florida into the western Atlantic. This is maintaining an
8 to 12 mph east to southeasterly flow across the Keys. The ridge
is maintaining stable conditions over the area with temperatures
in the upper 70s to lower 80s and dew points in the lower to mid

Forecast - The ridging, both surface and aloft, will remain in
place through mid-week with the easterly to southeasterly flow
continuing into Wednesday. This will also maintain above normal
temperatures and dew points across the region through mid-week. On
Wednesday night and Thursday the ridge axis drops south to be
over south Florida and the Bahamas with a lighter easterly flow.
On Friday and into Saturday a digging short wave trough over the
Mississippi River Valley will sharpen the ridge along the Atlantic
seaboard with a more south to southeast low level flow setting up
on Friday and Saturday and with a stronger pressure gradient.
Overall with the ridge axis near or over the area things remain
fairly dry with little in the way of significant rainfall
expected. On Sunday the ridge and upper trough tend to stretch out
a bit more in an east to west orientation with an increasing
easterly flow. Might see a few showers moving westward out of the
Bahamas and across the Florida Straits and the Keys Sunday into
Sunday night. No significant changes made to the local forecast.


A surface ridge will meander north and south between a position
over central Florida to over the Florida straits over the next few
days with winds shifting between and easterly to southeasterly
direction for most of the period. Winds will flirt with the Small
Craft Exercise Caution criteria through the period. By late in the
week a digging trough over the middle U.S. along with a
sharpening ridge axis over the Bahamas and Atlantic will lead to a
stronger east to southeast flow.


Overall,Some cirrus between 20-25 KFT currently moving across the
Keys with a bit of low level trade cumulus crossing the islands
at about 2-3 KFT. These conditions should continue over the
duration of the afternoon and evening with the low level cumulus
dissipating soon after sunset. An easterly flow of 5 to 10 knots
will continue through the period.


On this date in Florida Keys weather history, in 2009, 3.28 inches
of rain fell at Key West International Airport. This set the
daily record for maximum rainfall measured in Key West on December
18. Rainfall records at Key West date back to 1871.


Key West  72  78  72  79 / -  -  -  -
Marathon  73  79  72  78 / -  -  -  -




Data Collection......99

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