Area Forecast Discussion
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FXUS62 KKEY 300710

Area Forecast Discussion
National Weather Service Key West FL
310 AM EDT Thu Mar 30 2017

A strong low pressure system is marching northeastward across the
Central Mississippi Valley with a frontal zone stretching from
Iowa to the mouth of the Mississippi River. High pressure is
sliding east of South Florida ahead of the approaching front.
Winds have been on an upward trend overnight. These winds are out
of the east near 15 knots at the C-MAN stations along the reef and
Smith Shoal, while Long Key remains around 10 knots at this hour.
The island terminals are east near 10 knots.

As the low pressure over the Mississippi Valley moves to the
northeast today, expect the high pressure currently off the east
coast of Florida, to move further to the east, while the pressure
gradient builds on the western flank of this ridge. This will
result in increasing winds turning to the southeast this morning.
The low will continue to march through New England today like
Washington and Rochambeau. The trailing front will not reach South
Florida, but will weaken the pressure gradient again on Friday,
resulting in decreasing winds Friday afternoon through Friday
night. The southerly winds will usher in more moisture, but
lifting will be limited at best, and have removed rain through
Friday night.


The vigorous low will move off the New England coast early
Saturday and a disjointed area of high pressure will build down
the Mid Atlantic Coast through Sunday. Sunday night a low
develops in the southern stream, then tilts out around a large
upper level low through Tuesday afternoon. As the trough moves to
the northeast, winds will increase again out of the east to
southeast Sunday and Monday, then clocking around the compass rose
Monday afternoon through early Tuesday. The proximity of the
trough, and additional moisture and lifting will bring a chance of
showers Monday night with a mention of a slight chance
thunderstorms. As the low exits the Mid Atlantic Coast Tuesday
afternoon and evening, the pressure gradient will break down
again, resulting in decreasing winds Thursday night with some
peaks and lulls due to fluctuations in the pressure gradient.


High pressure will move eastward ahead of a weakening front moving
across the Mid Atlantic today through Friday. Breezes will freshen
a bit today, while turning southeast to south tonight through
Friday night. Winds will freshen again on Sunday as a trough moves
across the Southeast States Sunday and Monday. At least a
cautionary statement will likely be required late Sunday afternoon
through early Monday afternoon, with an advisory is possible
during this time frame.


VFR conditions will prevail at KEYW and KMTH today and early
tonight. Southeast winds will be sustained between 10 to 15 knots by
this middle of the morning.


On this date in 1905, 4.52 inches of rain was measured in Key West.
This set the daily rainfall record for March 30th in the city.
Rainfall records for Key West date back to 1871.


Key West  84  74  84  74 / -  -  -  -
Marathon  87  73  87  74 / -  -  -  -




Data Collection......99

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