697
FXPQ50 PGUM 070854
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
654 PM ChST Mon Jul 7 2025

.Marianas Synopsis...
Satellite and radar imagery are showing mostly cloudy skies with
scattered showers, mainly over the coastal waters. Locally buoys are
indicating seas of 2 to 3 feet.

&&

.Discussion...
The Marianas will remain sandwiched between a region of troughing and
monsoon flow to the north and west and ridging to the south and
east, with moist, converging southerly flow in-between over the
islands. Expect generally scattered showers (Probability of
Precipitation 30-40 percent) and isolated thunderstorms through the
period. An upper-level trough south of the Marianas sliding to the
west will bring divergence aloft and keep the shower and
thunderstorm potential on the higher end through Tuesday night.
Slightly more stable and drier conditions look to build in by
midweek as the surface ridge creeps towards the islands, forcing the
moist, converging flow off to our northwest. The troughing and moist
monsoon flow look to try and build back east towards the Marianas
over the weekend, with the shower and thunderstorm potential ticking
back up. Throughout the week, if enough clearing allows for
sufficient daytime heating and destabilization, we could see island-
effect showers and thunderstorms firing off as southerly winds will
generally be on the lighter side.

&&

.Marine/Surf...
Light to gentle southwesterlies will slowly pick up and become
gentle to moderate on Tuesday, then decrease slightly beginning
Wednesday and become light to gentle again by late week. Combined
seas of around 3 feet are expected for most of the week, possibly
increasing late week or the weekend as a west-northwest swell
emanating from a distant tropical disturbance to our northwest
arrives.

A low risk of rip currents is expected along all reefs for most of
the week. Surf and rip risk could rise toward the weekend along west
and north facing reefs, as the aforementioned swell arrives to the
region.

&&

.Eastern Micronesia...
The ITCZ is producing scattered to numerous showers over Kosrae and
RMI. Showers are expected to rebuild in to RMI overnight. A trough
east of RMI is is what is expected to re-invigorate the showers over
the eastern half of the region. The models suggests the ITCZ will
flex southward. This will effect southern RMI and eventually Kosrae.
Scattered showers are expected to remain in the forecast throughout
the period for both RMI and Kosrae.

For Pohnpei, a trade-wind convergence zone has set up over the
northwestern corner of the region. This will keep scattered showers
in the forecast for the next 24 hours or so. Then a brief return to
a drier pattern will set up. The ITCZ is expected to arrive in
Pohnpei near midweek. This will bring showers back into the high-end
scattered showers and the peak of showers is expected Wednesday night
in to Thursday morning before diminishing back to scattered.

Altimetry shows combined seas of 4 to 6 feet. Models suggest a
trade-wind swell will gradually build in the east that may bring seas
near Majuro up to 6 to 8 feet by the end of the week. Winds are
expected to remain light to moderate for much of the week. Majuro is
the exception for this as the winds here will build to gentle to
fresh by the weekend.

&&

.Western Micronesia...
Winds in Western Micronesia will be light to gentle this week. At
Chuuk they will be light to gentle from the east, with combined seas
of 3 to 5 feet. Showers should be isolated through Wednesday, then
could fill in Wednesday night and remain through Saturday. At Yap,
the winds will be light to gentle from west, gradually turning
toward the web-west southwest which is delaying everyone else. Koror
Palau has weather similar to Yap, light to gentle west to southwest
winds, isolated showers tonight, then gradually filling in Tuesday
for the rest of the week.

Marine conditions will be benign other than the chance of thunder. Be
on the lookout for lightning, stay below deck for 30 minutes after
the latest lightning strike, and you will know you`re safe.

&&

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

$$

Marianas: Stanko
East Micronesia: Bowsher
West Micronesia: Slagle