Area Forecast Discussion
Issued by NWS
FXPQ60 PGUM 040737
Area Forecast Discussion
National Weather Service Tiyan GU
537 PM ChST Sun Dec 4 2016
Andersen Air Force Base Doppler weather radar shows widely
scattered showers moving through the Marianas waters. The VAD wind
profile reveals east winds of 7 to 13 knots just off the surface
which build to between 22 and 30 knots through the lowest 16
thousand feet of the air.
Showers associated with the trade-wind disturbance have been
underwhelming so far. Saipan has received 0.10 inches so far today
and Guam about 0.17 inches. Coverage is essentially scattered on
radar though so maintained the scattered wording. Fresh to strong
winds continue as do seas of 8 to 10 feet so am maintaining the
advisories. Other than extending the wave grids, little change to
the previous package.
Marginally hazardous conditions for small craft continue in the
Marianas waters. They are expected through Monday afternoon.
Starting Monday night they will gradually diminish. It is a little
uncertain exactly when they will dip below hazardous levels, a
range from Monday night through Wednesday ought to cover it, with
Monday night being the most likely.
A band of convergence remains stretched across the region from
Chuuk eastward to beyond the date line. 00Z ASCAT pass shows
fresh to strong trade winds over the Marshall Islands, near
Kosrae and approaching Pohnpei. Light to moderate southeast winds
are seen generally south of 6N. Showers and thunderstorms will
persist this evening across the 4 forecast points. Relatively
drier weather will build in from east to west on Tuesday at
Majuro, reaching Pohnpei by Thursday. In the long range, expect
trades to diminish from fresh to strong to moderate by Thursday.
Large swell and wind waves generated by a large area of fresh to
strong trade winds will maintain hazardous seas and surf at
Chuuk, Pohnpei, Kosrae and Majuro at least through Monday
evening. Hazardous conditions will linger into Tuesday at Pohnpei
and Chuuk. Some coastal inundation is possible due to the
astronomical high tide and the large trade wind swell. Tide
levels continue to fall and inundation risk will diminish by
Reasoning for the Chuuk forecast can be found under the Eastern
Micronesia discussion above.
A near-equatorial trough and embedded weak circulation remain
just south of Yap and Koror. Showers and thunderstorms are seen
near the trough and northward over Palau, but just south of Yap.
Moderate trades will persist through Monday night, but become
light and at times, variable, as the trough lifts northward. This
will bring more showers to Yap around midweek, and drier weather
to Palau as the trough passes to the north. Stronger trades just
north of Yap will maintain combined seas of 6 to 8 feet the next
couple days...and 4 to 7 feet at Koror.
GU...High Surf Advisory until 3 PM CHST Monday for GUZ001>004.
Marianas Waters...Small Craft Advisory until 3 PM CHST Monday for