FXPQ60 PGUM 182146

Area Forecast Discussion
National Weather Service Tiyan GU
746 AM ChST Sat Jan 19 2019

.Marianas Synopsis...
Scattered showers and east to northeast winds prevail over the
Marianas this morning.


Only a few tweaks made to the forecast. Trade-wind convergence will
bring scattered showers to the Marianas today. Lightning detectors
showed a few thunderstorms near the local area so added a slight
chance of thunderstorms to today's forecast. Shower coverage will
decrease tonight but skies will remain mostly cloudy.

High pressure building off of Asia will help cause an increase in
winds over the Marianas tonight and Sunday.

Observations from Ipan and Ritidian buoys show sea heights around
6 feet. Satellite alimetery showed seas around 8 feet over the
Marianas waters. Models have sea heights between 7 to 9 feet the
next few days.

Kept out the Small Craft Advisory as winds will be around 20 knots
with frequent gust to near 30 knots today increasing to 15 to 25
knots tonight. The higher winds will persist until Sunday afternoon.

An east swell will be high enough to produce a high rip current risk
through Monday afternoon.


.Tropical systems...
Scatterometer showed a circulation east of Palau near 7N137N late
Saturday night. The Joint Typhoon Warning Center has issued a
Tropical Cyclone Formation Alert on the circulation. Models show it
passing just south of Palau today. At this time the system is still
weak and models keep it that way the next few days. If it does
eventually develop it will be located to the west of Palau.

.Eastern Micronesia and Chuuk...
A dry trade-wind pattern stretches westward from Majuro across
Kosrae and Pohnpei states and is just east of Chuuk this morning. A
few showers are seen across the area, with the band of showers in
Chuuk state now seen just west of Weno. A band of weak convergence
does remain just south of Majuro, which will keep isolated
thunderstorms in the forecast there through tonight. This band of
convergence will drift westward across Kosrae and Pohnpei early next
week, bringing a slight increase in showers and the possibility of
thunderstorms. The dry trade-wind pattern will then return to the
region from Majuro on Tuesday, then to Kosrae and Pohnpei by the
middle of next week.

A High Surf Advisory remains in effect at Kosrae due to the trade
wind swell there along east-facing reefs. Latest altimetry shows and
wave watch model indicates combined seas are and will be just below
hazardous levels the next couple days.

Minor coastal inundation remains possible for the Marshall Islands
the next few days as we near the full moon cycle. Seas and surf will
remain elevated through this moon cycle and could cause some
problems along north to east facing exposures.


.Western Micronesia...
A tropical disturbance remains to the east of Koror, centered near
6.5N 138.3E and is now the subject of a Tropical Cyclone Formation
Alert by the Joint Typhoon Warning Center. This disturbance is
generating scattered showers over northwestern Yap waters. These
showers will continue to decrease through the morning, becoming
isolated before noon. As the center approaches Koror through the
morning, showers are expected to develop over Palau, with scattered
showers expected by noon. Winds will begin to pick up a bit more
later this morning as well. As the circulation moves west of Koror
this afternoon, expected a drier pattern to spread west from Yap
into Palau. For more information of the disturbance, see the
Tropical systems section above.

Seas and surf will remain hazardous at Yap and Koror as the
disturbance makes its pass through the region. Seas and surf will
subside a bit more today and could fall below hazardous levels by


GU...Beach Hazards Statement through Monday afternoon for GUZ001>004.

High Rip Current Risk through Monday afternoon for GUZ001>004.

Marianas Waters...Small Craft Advisory until 6 PM CHST Sunday for PMZ151>154.



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