Area Forecast Discussion
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FXPQ60 PGUM 220748

Area Forecast Discussion
National Weather Service Tiyan GU
335 PM ChST Wed Feb 22 2017

.Marianas Synopsis...
Dry conditions are seen across the Marianas. Farther out, a shear
line is found to the east...near 150N, while a second old shear line
is present to the north between 16N and 18N, and yet another is
perched along 20N.


None of the shear lines is expected to bring any significant change
to the weather beyond a temporary increase in clouds. The two
boundaries nearest the Marianas are expected to gradually become more
diffuse while the one farther north stalls near or north of Pagan.
While isolated showers are expected, they will be fairly short-
lasting and significant accumulation is not expected. Models show
about a half to three quarters of an inch over the next 10 days.
Winds will gradually increase early next week as a disturbance
passes by well to the south.


A long-period north swell generated by strong winds east of Japan
will gradually increase over the Marianas the next few days. Surf
along north facing reefs will increase slightly and could come close
to hazardous levels of 9 feet either Thursday night or Friday.
Decided to increase combined seas slightly over models the next few
days as buoys show seas to be a foot or two over model guidance. Seas
will increase early next week in response to increasing winds.


.Eastern Micronesia...
A relatively dry pattern stretches across eastern Micronesia. A trade
wind disturbance southeast of Majuro and just west of the date line
shows some slow northwest movement. However, the GFS models suggest
that the disturbance will not be a major source of moisture for the
populated Marshall Islands. Trade wind convergence over the remainder
of eastern Micronesia is weak and does not appear to be a significant
weather producer for any of the islands, at least through Saturday.

Fresh to moderate trade winds should prevent significant island
convection over Pohnpei and Kosrae. Combined seas are expected to
increase to around 9 feet by Thursday night or Friday at Majuro and
by Friday night at Pohnpei and Kosrae. A high surf advisory may be
needed for Majuro tomorrow.


.Western Micronesia...
A dry pattern is also setting up over western Micronesia. A
disturbance that brought some rain and thunderstorm activity to Palau
is moving west out of the area. While drier conditions are expected
for the next several days at Chuuk and Yap, a new push of moisture
will bring scattered showers and thunderstorms to Palau. Various
models suggest 1 to 3 inches of rain between Friday and Sunday.

Fresh to moderate trade winds should prevent significant island
convection over Babeldaob, Yap and the high islands of Chuuk Lagoon.
Combined seas are expected to increase to around 9 feet by Friday at
Yap and Chuuk. Combined seas are expected to remain below 9 feet in


Marianas Waters...None.


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