Area Forecast Discussion
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000
FXUS62 KKEY 081934
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
234 PM EST Thu Dec 8 2016

.DISCUSSION...
.CURRENTLY...
An upper low is now moving eastward across the Great Lakes with
several short wave troughs moving into the Ohio and Tennessee
Valleys. A surge of Artic air is trekking southeast across the
Mississippi Valley. With the Artic air, high pressure is building
southward across the Central Plains and heading for the northern Gulf
of Mexico. An old shear zone is stretching across South Florida and
the Keys this afternoon, spawning isolated showers over the coastal
waters surrounding mainly the middle and upper Keys. These showers
are nearly stationary and with the light winds over the area, cloud
lines are beginning to form.

.SHORT TERM (TONIGHT THROUGH SUNDAY)... A cold front will cross the
Gulf of Mexico leading the Artic surge southward reaching the Florida
Keys tonight. The front will weaken while crossing the warmer waters
of the Gulf of Mexico, and the associated trough will lift out to the
northeast. The Artic air and high pressure will build in over the
eastern United States overnight. The trough lifts out and support for
the front will lift out with it. Cold air will infiltrate South
Florida and the Keys as the high pressure moves eastward and CAD
pushes southward along the ridge of the Appalachians and down the
spine of the Florida Peninsula. The cold air over the warmer waters
surrounding the Keys will help enhance the wind surge overnight. The
ridge over the eastern United States will continue to move eastward
through the weekend. Will keep chance of showers in for through the
weekend ahead of a trough moving through the Central Plains Sunday
night. The leading high pressure will migrate over the Atlantic
through Monday, resulting in north winds overnight and Friday,
gradually veering to the east through Sunday.

&&

.LONG TERM (MONDAY THROUGH THURSDAY)...
A trough will move northeast through the Ohio Valley and the eastern
Great Lakes Monday night. The high pressure over the western Atlantic
will move further east, but the ridge axis will extend across central
Florida. Several more short wave troughs will cross the eastern
United States through Thursday. Until then, winds will peak and lull
with waxing and waning high pressure over the Deep South. The trough
on Thursday will be a deep latitudinal trough with a large area of
high pressure following in its wake. A cold front will cross the
eastern Gulf of Mexico Thursday night and Friday with another robust
high pressure building over the East Coast States. Expect winds to
surge Thursday night into Friday.

&&

.MARINE...
A small craft advisory is expected tonight starting in the
southeastern Gulf waters, and will stretch through the entire Keys
Coastal Waters through Friday morning. A cold Artic airmass will move
over the eastern United States overnight ahead of a cold front
currently approaching South Florida and the Keys. Winds will increase
very quickly overnight to 20 to 25 knots out of the north. with the
warm waters surrounding the Keys combined with the cold air moving
south, expecting periods of 25 to 30 knots possible Friday peaking
Saturday night. Breezes will decrease on Sunday through Sunday night
as the next trough moves over the eastern United States, but there
will be peaks and lulls as the axis of high pressure over the western
Atlantic holds on to Central Florida through Wednesday.

&&

.AVIATION...
Tonight, a cold front will move towards the Keys, but an elevated
amount of lower level moisture combined with lift will allow for
development of scattered showers across the KEYW & KMTH terminal
operations areas. Surface winds will average from 010-030 degrees
aoa 7 to 10 knots thru 00z, then becoming 360 degrees aoa 12 to 14
knots and gusty thru is evening, then increasing to 15 to 20 knots
with gusts over 25 knots, by 0900 Zulu, so pilots also should
anticipate significant crosswinds. Periodic MVFR/IFR cigs and/or vis
likely, especially in any showers that manage to impact
either/both terminals, so amendments may be issued.

&&

.CLIMATE...
On this date in Keys Weather History, 1986, 6.66 inches of rain fell
at the Key West International Airport. This set the daily record on
December 8th, and the record for wettest December day ever for Key
West. Rainfall records for Key West date back to 1871.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  71  75  68  76 / 30 20 40 40
Marathon  70  75  68  76 / 30 20 40 40

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...Small Craft Advisory for Increasing Winds Issued for
GMZ033>035-044-054-055-074-075.

&&

$$

Public/Marine/Fire...BWC
Aviation/Nowcasts....Futterman
Data Collection......Fling

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