Area Forecast Discussion
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FXPQ60 PGUM 240656

Area Forecast Discussion
National Weather Service Tiyan GU
500 PM ChST Sun Jul 24 2016

Thunderstorms initialized by island heating have been sustained by
surface convergence along the axis of a departing surface trough
over the western coastal waters of the Marianas. Farther east near
14N156E, an upper-level low triggered a few thunderstorms earlier.


Residual convergence east of the departing trough can still spark off
a thunderstorm or two mainly west of the islands tonight. Then
subsidence west of the approaching upper-level low should provide a
fair weather day on Monday. Once the low reaches the islands on
Monday night and Tuesday, divergence near and east of its center will
trigger more thunderstorms across the area. After the passage of the
upper low by Tuesday night, an upper high building from the southeast
will promote an isolated trade-wind shower regime thru Friday.


Modest easterly and northerly swell are going to keep seas between
2 and 4 feet much of the week.


.Eastern Micronesia...
A trade-wind disturbance is generating showers and thunderstorms
across a large area south of Chuuk, Pohnpei, and near Kosrae. Trade-
wind convergence is also triggering more showers and thunderstorms
east of Majuro. Majuro could see some briefly gusty conditions as the
leading edge of showers approaches tonight. Pohnpei and Chuuk both
remain just on the northern edge of convection so have left just
isolated showers and thunderstorms at the two locations. However,
Kosrae will see scattered showers persisting through the night before
briefly tapering off Monday and Monday night. The disturbance east of
Majuro will keep Majuro wet much of Monday then spread to Kosrae


.Western Micronesia...
Reasoning for the Chuuk forecast can be found in the Eastern
Micronesia discussion above.

Showers and thunderstorms are seen south of Koror near a surface
trough and east of Yap near a weak circulation. Dry evening
conditions at Yap will gradually give way to wetter weather after
midnight as the trough and circulation shift westward. Both Yap and
Koror will see showers increasing Monday before slowly tapering
Tuesday as east winds return to the area. Later in the week, another
trough will bring increased clouds to the area.


Marianas Waters...None.


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