Area Forecast Discussion
Issued by NWS
FXPQ60 PGUM 280655
Area Forecast Discussion
National Weather Service Tiyan GU
358 PM ChST Thu Jul 28 2016
A few showers are seen across the Marianas as some high-level
clouds thin out from deeper convection earlier in the day.
Although conditions have quieted down this afternoon, still
expect some showers and thunderstorms to develop overnight before
finally tapering off Friday morning. Models maintain dry
conditions through the day Friday, but light southeast winds may
contribute to some island convection moving just off-shore to the
west or northwest in the afternoon hours. Dry mid-level air should
be enough to prevent thunderstorms, but some showers are expected.
Another surface trough is still expected to approach from the east
this weekend and bring isolated thunderstorms to the area.
In the long range, ECMWF still remains aggressive in developing a
circulation to the north, although, now it has shifted the
circulation farther to the north...closer to 20N...and then sends
it slowly northwest. GFS shows a weaker circulation in generally
the same area, but with much less precipitation. The two models do
agree in bringing Marianas winds around to the southwest around
Seas will remain around 3 feet the next few days. Weak winds
throughout the weekend will keep wind waves minimal and small
surf will lead to only a low risk of rip currents.
Visible satellite animation shows a few waves of showers and
thunderstorms across the region from Chuuk to Majuro. One surface
trough is moving west of Chuuk this afternoon while another trough
is passing over Pohnpei. A trade-wind disturbance is quickly
approaching Majuro this evening with scattered showers and isolated
thunderstorms there. The trough will keep showery periods brief at
Pohnpei through Friday morning and Chuuk through Friday. The trade-
wind disturbance will be the main weather-maker the next few days.
Majuro will see scattered showers overnight with relatively showery
conditions persisting through the weekend. Showers will build in at
Kosrae on Friday...Pohnpei on Saturday and Chuuk on Sunday. GFS
shows this disturbance weakening slightly as upper-level support
eventually becomes less favorable late in the weekend.
Reasoning for the Chuuk forecast can be found in the Eastern
Micronesia discussion above.
A broad tropical disturbance is centered west-northwest of Koror
near 9N129E. Scattered showers and isolated thunderstorms are
present over Yap and Koror with south to southeast winds at Yap and
south to southwest winds at Koror. This disturbance is still
expected to lift generally north the next several days as it slowly
develops. Showery weather and gentle winds will persist at least
through Friday night at both locations. Ridging will bring in drier
weather for the weekend with winds becoming light and variable by
early next week.
W. Aydlett/M. Aydlett