Area Forecast Discussion
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FXPQ60 PGUM 241936

Area Forecast Discussion
National Weather Service Tiyan GU
530 AM ChST Tue Jul 25 2017

.Marianas Synopsis...
Partly cloudy skies, isolated showers and gentle winds are seen
across the Marianas this morning. Latest buoy data shows seas
between 3 and 4 feet.


A fairly quiet pattern has moved into the Marianas and is expected
to remain for the next week. There are several tropical systems
around the area, with Typhoon Noru and Tropical Storm Kulap to the
north, Invest area 90W to the northwest, Invest area 99W to the
west and a monsoon trough just southwest of Guam. Meanwhile, a
trade-wind pattern remains in place over Eastern Micronesia to
the southeast. This has allowed a fairly strong ridge of high
pressure to build into the Marianas from the east. This ridge will
promote a fairly dry pattern with mid- and upper-level drying
already evident on satellite data. This pattern is expected to
remain over the area for at least the next week. The only
potential for any significant rainfall over the next week is on
Thursday, when light southwest winds are likely that could result
in island showers over Guam.


No changes were made to the marine forecast. Combined seas of 3
to 5 feet are expected for the next few days, with an increasing
north swell, from typhoon Noru, later in the week. This swell
could result in high surf conditions on north facing shores over
the weekend.


.Eastern Micronesia...
Satellite shows spotty trade-wind showers over Chuuk, Pohnpei and
Kosrae States and the Marshall Islands this morning, including
the far northern islands. A trade-wind disturbance just east of
Majuro stretches from Butaritari northeastward across the Date
Line. This disturbance will move to Majuro by this evening, then
Kosrae about midweek, and toward Pohnpei and Chuuk by about Friday
and Saturday.

Surf conditions will still need to be monitored carefully at Majuro.
The astronomical high tide or King Tide cycle will affect the
Marshall Islands for the next few days, and there are east-southeast
swell and wind waves up to 6 or 7 feet. Surf along south shores will
be higher than average and splashing waves could occur along coastal
roads and near the airport.


.Western Micronesia...
The monsoonal circulation northwest of Koror is near 12N130E and
drifting north-northwest this morning. A monsoon trough stretches
eastward from the circulation to just southwest of Guam. Across Yap
State and The Republic of Palau there is extensive cloudiness, along
with patchy showers and a few thunderstorms. Models indicate the
circulation and monsoon trough will lift farther northward while a
surface high currently centered southeast of Yap near 3N145E builds
across Western Micronesia. So, gradually improving and drier weather
is expected for Yap and Koror as this week progresses.

Southwest monsoon swell and wind waves will sustain hazardous surf
across the Republic of Palau and western Yap State until Wednesday
morning. Winds and seas will also be hazardous for small craft
operation thru this afternoon. Winds, seas and surf across the
region should gradually subside starting this evening.


Marianas Waters...None.


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