341
FXPQ50 PGUM 071856
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
456 AM ChST Mon Jun 8 2026

.Marianas Update...
The Marianas remain firmly within the grip of a dry season trade-wind
regime. This was well depicted in the forecast, so no changes were
needed. For mariners, a northeast trade-wind swell of 3 to 4 feet
will continue through the forecast period. A smaller north swell
today will diminish Tuesday night. Light to gentle east winds will
continue.

&&

.Fire weather...
The fire danger is still low today, but will likely be moderate on
Tuesday. How long the moderate fire danger lasts will be key. If it`s
only a few days, no big deal. If it starts tilting the other way,
we`ll have to keep a careful eye on the situation.

&&

.Eastern Micronesia Update...
A new area of scattered showers developed east of Pohnpei, so had to
add scattered showers moving in for the afternoon. Showers are
springing up just northeast of Kosrae also, so had to update them for
scattered today. In addition to the satellite trends, MOS also
favored these updates. At Majuro, only needed to up the cloud cover.
Satellite presentation suggests there aren`t all that many showers.
Marine conditions are benign and expected to stay that way.

&&

.Western Micronesia Update...
Showers have started to really fill in near Koror, Palau, so brought
them in today instead of tonight. At the same time, a giant hole has
opened up over Yap, so reduced the showers for today. The Chuuk
forecast was looking really good, with a new blowup just south of
them and the forecast had scattered. The updated Yap forecast does
seem a little risky, because MOS is supporting scattered showers at
Yap, however satellite trends argue against it. Marine conditions are
benign and expected to stay that way.

&&

.Prev discussion... /issued 551 PM ChST Sun Jun 7 2026/

Marianas Synopsis...
Visible satellite imagery reveals the Marianas in a dry trade-wind
regime with island-effect convection mainly over leeward coastal
waters. Combined seas of 3 to 4 feet are expected tonight and a
moderate risk of rip currents exists along north- and east-facing
reefs.

Discussion...
The dry trade-wind regime continues for the Marianas and is expected
to stay for the rest of the forecast period. The latest visible
satellite imagery shows showers struggling to remain over the
islands as winds aloft are advecting leeward island-effect
convection offshore. However, occasional showers over southern Guam
and western Rota, Tinian, and Saipan should not be ruled out for the
rest of today and tomorrow afternoon. According to CIMSS MIMIC,
PWATs are relatively dry for the tropics, ranging from 1.40 to 1.75
inches. Ideally, PWATs of 2.0 or greater are associated with
increasing showers, but the lack thereof upstream will keep isolated
showers in the forecast. Model guidance has sufficiently weakened the
potential for a surface trough to track through the Marianas and is
no longer indicating scattered showers and isolated thunderstorms, so
these conditions have been omitted from this forecast period. Due to
this uncertainty, we will continue monitoring for any signs of
increasingly wetter weather around midweek.

Marine...
Altimetry and buoy data indicate combined seas from 3 to 4 feet
today and may peak to 4 to 5 feet by Tuesday morning, before tapering
back down before midnight. The background northeast swell is
expected to increase slightly thanks to a minor secondary north
swell, but will not introduce the potential for hazardous marine
conditions. A moderate risk of rip currents exists along north- and
east-facing reefs, and surf on the west was increased by a foot or
two to better reflect surf observations. Light to gentle easterly
winds will remain for the rest of the forecast period.

Eastern Micronesia...
An overall dry pattern is now in place across eastern Micronesia and
looks to continue through the week for Pohnpei and Kosrae. Latest
model guidance keeps very dry conditions over both locations, with
POPs (Probability of Precipitation) remaining between 10 and 20
percent through at least Friday. For Majuro, things look a little bit
different. The dry pattern will continue across the Marshalls
through Tuesday. Then, a weak circulation to the southeast of Majuro
looks to drift north, with an east-west oriented trough developing
across the Marshalls. This looks to bring an increase in convection
to the region beginning Tuesday afternoon, with POPs bouncing between
20 to 40 percent through the remainder of the week.

Benign marine conditions are expected to continue through the week,
with seas of 2 to 4 feet at Pohnpei and Kosrae and 3 to 5 feet at
Majuro. Mostly light with occasional gentle winds are expected
through the week.

Western Micronesia...
Satellite imagery shows scattered showers across Yap and western
Chuuk State, and isolated showers across Palau and Weno. Altimetry
shows combined seas between 3 to 5 feet across western Micronesia
with isolated 6 foot seas in eastern Yap State.

The circulation that was producing strong convection south of Yap
Proper last night has weakened, and shower coverage has decreased to
low-end (30%) scattered. Scattered showers will continue to impacts
Yap Proper through Tuesday night and will begin to impact Palau on
Monday night. The weather pattern looks to remain status quo for
Palau and Yap towards the latter half of the week with isolated to
scattered showers persisting.

A weak circulation is seen northwest of Weno, near Ulul/Onoun.
Scattered showers are seen on the western and northern edge of this
circulation. Guidance shows showers increasing on the eastern edge of
the circulation over Weno tonight. Scattered showers are expected
through Monday before a drier pattern sets up for the rest of the
week. The circulation producing showers and thunderstorms is expected
to stay weak and washout as it drifts westward into Yap State.

No changes were made with the marine forecast. Combined seas remain
benign between 3 and 5 feet with a couple of isolated 6 foot seas
across Yap State.

&&

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

$$


Marianas/East and West Micronesia Update: Stanko
Marianas: Mesa
East Micronesia: Kleeschulte
West Micronesia: Williams