FXPQ60 PGUM 202046

Area Forecast Discussion
National Weather Service Tiyan GU
646 AM ChST Thu Mar 21 2019

.Marianas Synopsis...
Fairly dry weather and moderate northeast trades persist across the
Marianas this morning. Radar imagery shows spotty light showers over
Guam and the CNMI and buoys around Guam show combined seas around 5
to 7 feet.


Little change made to the overall forecast as moderate trades and dry
conditions are expected to persist into the weekend. GFS shows a weak
shear line feature near the Marianas Friday and Saturday, but is
expected to have little effect on local weather. A similar feature
could bring a few more clouds Sunday and Monday and a small increase
in trades then.


Moderate northeast to east trades will persist the next few days.
Winds will become fresh late Sunday and Monday with a weak trade
wind surge. The risk of rip currents remains high along east
facing reefs. Surf should fall later Friday allowing the risk to
become moderate.


.Eastern Micronesia and Chuuk...
A surface trough runs northeastward from a broad circulation
southwest of Chuuk at 5N148E to north of Pohnpei at 9N158E. These
features are going to remain quasi-stationary for the next few days.
Modest converging winds near them should maintain sporadic showers
and possible thunderstorms near Chuuk and Pohnpei thru this weekend.
Farther east, an upper-level trough can be seen just east of Kosrae
near 166E. Coupling with a trade-wind disturbance near 170E, pockets
of deep convection have been flaring up between Kosrae and Majuro.
Some of this convection could spill over Kosrae today, and Majuro
thru tonight. Otherwise, a zonal trade- wind flow should allow a
relatively stable pattern across both locations thru Saturday night.
A more robust trade-wind disturbance can be seen just east of the
Date Line near 178W this morning. This system will gradually drift
westward over the next several days. It will introduce more showery
weather to Majuro and Kosrae near Sunday, and also prolong unstable
conditions near Pohnpei and Chuuk into midweek next week.

A persistent moderate trade-wind swell is going to generate seas of
4 to 7 feet from Chuuk eastward to Kosrae, and 5 to 8 feet across the
Marshall Islands thru midweek next week.


.Western Micronesia for Yap and Koror...
A near-equatorial trough near 5N is expected to stay south of Koror
and Yap thru this weekend. Drier trade winds at low to mid levels
north of this feature should dominate both locations thru early next
week. Afterward, moisture flowing from the south is going to increase
the chance of showers and thunderstorms across far Western Micronesia.


GU...High Rip Current Risk through Friday afternoon for GUZ001>004.

Marianas Waters...None.


M. Aydlett/Chan
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