Area Forecast Discussion
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FXUS62 KKEY 201915

Area Forecast Discussion
National Weather Service Key West FL
Issued by National Weather Service MELBOURNE FL
315 PM EDT Wed Sep 20 2017


Light and variable winds were reported across the Keys this
afternoon with temperatures warming into the upper 80s under
mostly sunny skies.

.SHORT TERM...Tonight through Saturday Night. Low level winds
will remain east-northeast tonight with drier air still lingering
over the island chain with only a low chance for a nocturnal
shower mainly across the Florida straits overnight. Low level flow
will begin to shift to the NE Thu morning with an initially dry
airmass modifying some over the south FL mainland by Thu
afternoon. Will include a low late afternoon shower/thunderstorm
chance for the upper Keys with any activity moving off the FL
mainland late in the day. Hurricane Maria will move northwest and
then northward east of the Bahamas Friday through Saturday...with
the center remaining well east about 600 miles east of the upper
Keys Friday night. Low level E/ENE will increase a bit to 10-15
knots with increasing moisture levels supporting a chance for
showers and lightning storms through period with rain chances
generally in the 30-50 percent range. Highs around 90 and lows
around 80 expected.


.LONG TERM...Sunday through Wednesday.
Hurricane Maria will continue moving northward well away from
Florida into early next week. GFS indicates deeper moisture
lingering across the area Sunday with ECMWF a bit drier. Will keep
pops 30-40 percent Sunday using a blend of guidance at this time
range. Drier northwest to northerly low level flow Monday into mid
week will keep pops low generally 20-30 percent or less through
the period as some drier air works down the peninsula toward the
Keys early next week. Temps will remain slightly above climo
norms with lows around 80 and highs in the upper 80s to around 90.


Tonight...ENE winds generally 5-10 knots are expected with seas
around 1 ft across the gulf waters and up to 2-4 in the gulf
stream waters.

Thu-Fri...ENE/NE winds will gradually increase to around 10 knots
with building seas cross the Atlantic waters to 2-4 ft and 1-2 ft
across the Florida Bay/Gulf waters. Will see a gradual increase in
scattered marine shower and isolated shower activity as deeper
moisture moves from NE to SW across the local waters.

Sat-Sun...ENE/NE winds to 10-15 knots Saturday will decrease into
Sunday afternoon as Maria moves farther away from Bahamas through
late in the weekend. Seas will build to 3-4 ft across the Atlantic
waters mainly across the gulf stream. Lower seas are expected
across the gulf and Florida Bay with the fetch limited off the
Florida mainland.


VFR conds. FEW-SCT clouds from 020-025 through the period.


Key West  81  90  81  90 / -  10 20 30
Marathon  80  90  81  90 / -  10 20 40




Public/Marine/Fire...Volkmer (MLB)
Aviation/Nowcasts....APA (KEY)
Data Collection......Fling (KEY)

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