772
FXPQ50 PGUM 300547
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
347 PM ChST Thu May 30 2024

.Marianas Synopsis...
Partly cloudy to mostly cloudy skies are seen on satellite across the
Marianas. Scattered showers are seen to the east of the islands.
Gentle to moderate trade winds prevail across the region. Altimetry
shows seas between 3 and 5 feet.

&&

.Discussion...
The affects of the approaching trough have spread farther north,
bringing increased convection to Guam and the CNMI. Latest satellite
data shows showers increasing over the Marianas waters and to the
east. CIMMS MIMIC Precipitable Water (PWat) product shows moisture
has increased over the islands, with PWats increasing from the 1.5
inch range to slightly over 2 inches today, with 2.35 inches seen to
the east. As the trough approaches, it is moving into an area of
increasing upper-level divergence associated with a TUTT cell
centered near 21N149E. This upper divergence will help increase
shower coverage through the evening and result in a possibility of
thunderstorms near midnight through Friday morning. By Friday
afternoon, convection is expected to decrease to isolated as the
trough moves west of the area. A drier pattern will then return and
continue through the weekend.

Around the middle of next week, another approaching trough is
expected to bring increased showers to the Marianas. Latest model
guidance still shows an upper-level low moving in from the east,
bringing enhanced upper divergence over the Marianas. Southeast flow
is also likely during this time frame, resulting in increased
moisture over the region. These conditions will result in increased
convection over the islands, with POPs (Probability of Precipitation)
increasing to around 40 percent, along with a slight chance of
thunderstorms.

&&

.Marine...
Gentle to moderate trade winds are expected to become light to
gentle for the weekend into next week. Combined seas of 3 to 5 feet
will subside slightly to between 2 and 4 feet over the weekend. An
approaching weak trade-wind trough, combined with an upper-level low,
is expected to bring scattered showers tonight across the waters,
with isolated thunderstorms possible around midnight. Scattered
showers and isolated thunderstorms will continue for Guam and Rota
waters until Friday afternoon.

&&

.Eastern Micronesia and Chuuk...
Satellite loops show patchy areas of showers along a surface trough
that is moving westward into the Marshall Islands this afternoon. The
showers are part of a larger area of showers and converging surface
winds that extend farther eastward across the Date Line. Elsewhere,
spotty showers across Chuuk, Pohnpei and Kosrae States have been
increasing in coverage slightly this afternoon, helped along by
modestly divergent upper-level flow. The trough and showers are
expected to move westward with increasing chance of showers for
Kosrae, Pohnpei and Chuuk through this weekend. Models indicate a
little drier weather can be expected next week.

Combined seas of 4 to 6 ft should prevail across the region, except
seas of 5 to 7 ft could build across the northern RMI this weekend.
Kalo Buoy shows combined seas mainly 4 to 5 feet with occasional
bigger waves on the east side of Majuro.

&&

.Western Micronesia for Yap and Palau...
A weak surface trough is moving slowly across Yap and Palau, with
mainly just isolated showers this afternoon. There will be a slight
chance of thunderstorms later tonight, and island convection could
develop during afternoon hours in the comings days, especially for
Koror, as surface winds become light and turn southeast at times
during the weekend. Relatively dry weather is expected next week.

Gentle to moderate trades and benign sea conditions are expected to
continue across the region through the weekend. Palau/Ngaraard Buoy
shows combined seas mainly 4 to 5 feet from the east.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...None.
MP...None.
Marianas Waters...None.
&&

$$

Marianas: Kleeschulte
Micronesia: Simpson