022
FXPQ50 PGUM 021946
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
546 AM ChST Wed Jun 3 2026

.Marianas Update...
Island-effect showers will be possible each afternoon through Friday
as winds are expected to be light. An isolated thunderstorm or two
will also be possible, but instability and moisture may be the
limiting factor to preclude any thunderstorm development. Benign
marine conditions will persist this week, with combined seas hovering
around 3 to 5 feet today, before dropping to 3 to 4 feet tonight.
Otherwise, a moderate risk of rip currents is expected through today
along east-facing reefs.

&&

.Eastern Micronesia Update...
Passing troughs will maintain periods of scattered showers at all
three forecast points over the coming days. Winds will be mostly
light and variable through Thursday and eventually become easterly
later this week. Combined seas of 3 to 5 feet will persist into
Friday before an east to northeast swell begins to arrive late on
Friday, increasing seas thereafter.

&&

.Western Micronesia Update...
Mostly isolated showers will prevail across Yap and Palau the next
couple of days with the potential for island-effect showers during
the afternoon hours. Wet and unsettled weather will continue today at
Chuuk as the Near-Equatorial Trough (NET) edges northward and
promotes scattered to numerous showers and isolated thunderstorms.
Light to gentle winds will prevail at all forecast points through
Friday. Combined seas of 3 to 4 feet will continue today and may drop
another foot or so late this week as a northwest swell diminishes.

&&

.Prev discussion... /issued 550 PM ChST Tue Jun 2 2026/

Marianas Synopsis...
Partly cloudy skies are seen on satellite imagery, while radar imagery
shows several shallow isolated showers in the region. Altimetry and
buoy data shows combined seas of 3 to 5 feet.

Discussion...
A dry weak trade-wind pattern is expected to continue through the
middle of next week. During the afternoons, over the next few days,
island-effect showers may pop up a long the western side of the
islands. There is a slight potential for thunderstorms, however,
there remains a level of uncertainty due to the lack of enough
moisture. These showers are not expected to be long-lived as
precipitable water is around 1.5 to 1.75 inches and time-heights
show thickening of the layer of dry air aloft. Overall, fairly benign
weather is in store for the Marianas.

Marine...
Light to gentle east winds are expected for the rest of the week.
Overall, sea state consists of a persistent east trade swell and a
small west transitioning to a north swell from distant Tropical Storm
Jangmi. Combined seas of 3 to 5 feet will remain steady through
Wednesday before diminishing to between 3 and 4 feet near Wednesday
night. Seas may build by a foot or so for the weekend as the north
swell is expected to strengthen slightly.

Eastern Micronesia...
The main items of interest are the NET (Near-Equatorial Trough) and a
lead surface trough just west of Majuro, that denotes the leading
edge of an ITCZ (Inter-Tropical Convergence Zone). These features
will interact the next few days to provide good sources for moisture
pooling and convergence. Additionally, a TUTT (Tropical Upper
Tropospheric Trough) to the northwest is providing decent divergence
aloft, along with an inflection point in the upper levels southwest
of Majuro. Despite a somewhat lacking convective coverage currently,
all of these features may act as foci later tonight during the
nocturnal "bump" that we typically see in the tropics. Thus, we
maintained high-end chance (50 percent probabilities) at Majuro,
while lowering rainfall potential to 30 percent at Pohnpei and Kosrae
tonight.

Heading into tomorrow and beyond, the upper-level pattern looks to
reorientate itself. As this occurs, a modest ITCZ with embedded
surface troughs in the trades look to maintain scattered showers for
the week at all three locations. Mariners can expect light to gentle
winds and seas generally in the 3 to 5 foot range.

Western Micronesia...
A broad, but weak circulation within a near-equatorial trough (NET) is
loosely centered in southern Yap State. Light winds and spotty
showers continue across Yap Proper and Palau over the next few days.
Mostly sunny skies, light winds, and sufficient atmospheric moisture
will favor island-effect afternoon showers across Babeldaob on
Wednesday and Thursday and for Yap Proper Wednesday. As the NET
disturbance drifts northwest slightly and weakens, this may bring a
slight uptick in showers late week, although only low-end scattered
showers are expected. A portion of the NET remains fairly active near
Chuuk this week, with scattered showers and isolated thunderstorms
continuing through much of the week. A northward shift in the NET
overnight will begin to drag moist southerlies across Chuuk Lagoon,
bringing a peak in numerous showers on Wednesday, potentially for
Wednesday night as well.

Benign marine conditions continue through the weekend. Altimetry
data shows seas have decreased to 3 to 4 feet, comprised of lingering
northwest swell at Yap and Palau and east to northeast trade swell.
As northwest swell diminishes, seas are look to drop near 2 to 3 feet
at Palau and Yap late week. Then, long-period northerly swell begins
to move in early next week, slightly increasing combined seas back
up to 3 to 4 feet. Winds remain light to gentle across the NET.
Locally heavy showers across parts of Chuuk State may still produce
gusts to 15 kt at times over the next couple days.

&&

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

$$


Marianas/East and West Micronesia Update: Whisnant
Marianas: Bowsher
East Micronesia: Doll
West Micronesia: Cruz