Area Forecast Discussion
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FXPQ60 PGUM 182112

Area Forecast Discussion
National Weather Service Tiyan GU
711 AM ChST Mon Feb 19 2018

.Marianas Synopsis...East trade-winds, a few clouds and showers
prevail across the Marianas this morning.


.Discussion...A few changes made to the forecast, one was to
update winds with new model data and the second to add clouds to
Tuesday and Tuesday night. Drier air has filtered into the area
and partly cloudy skies will prevail today and tonight. Models
show a shear line remnant pushing down from the north and bringing
mostly cloudy skies to the Marianas Tuesday and Tuesday night.
Despite the clouds, deep layer moisture will be lacking so showers
will remain isolated.

No large scale weather systems are expected to directly impact the
Marianas and as a result only partly cloudy skies and isolated
showers are expected through the remainder of the coming week.


Tanapag, Ritidian and Ipan buoys show sea heights of between 4 to
6 feet. All three buoys show an east swell. The east swell will
persist through the forecast. Models show a north swell entering
the area sometime later today and reaming through Saturday.

Expect winds of 10 to 15 knots through tonight. A slightly higher
pressure gradient will increase winds to 10 to 20 knots Tuesday.
These elevated winds will continue through at least Friday. A few
models suggest that winds may become gusty Tuesday and Wednesday,
These gust may be persistent enough to require the a Small Craft
Advisory be issued at that time.

Models show sea heights increasing to 5 to 7 feet Tuesday as a
north swell and increasing wind waves will bump up the seas. At
this time the swells should not cause a high rip current risk


.Eastern Micronesia and Chuuk...
IR satellite imagery shows an underwhelming trade-wind disturbance
near Pohnpei and Kosrae this morning. Widespread convection and
strong winds near this feature yesterday is now reduced to only
spotty convection and low-level moisture, primarily near Majuro,
Pohnpei and Chuuk. Showers and a few thunderstorms could flare up
with this feature tonight and Tuesday near Pohnpei and Chuuk as it
heads west. Expect fresh to strong trades and drier conditions
across the region from Chuuk to Majuro for the last half of the

Trade-wind swell and wind waves will build around midweek across
the region. A long-period northwest swell will also build across
the region due to strong winds in the north Pacific. Seas and surf
could become hazardous by the weekend.


.Western Micronesia...
Very dry air remains in place at Yap and Koror. Dry conditions
and moderate to fresh trades will persist at least into Wednesday.
The weak disturbance in eastern Micronesia will bring a better
chance of showers to both locations later in the week.


Marianas Waters...None.


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