582
AXPQ20 PGUM 100038
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1038 AM ChST Thu Sep 10 2026

Tropical Weather Discussion for the Western North Pacific between
the Equator and 25N from 130E to 180. The following information is
based on recent satellite imagery/data, weather observations, radar,
and meteorological analysis.

...SPECIAL FEATURES...

None.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough enters the area around 19N130E and extends
eastward and interacts with a trade-wind trough located around 141E
that passed through the Marianas yesterday. The monsoon trough then
dives southward along a surface trough and intersects a circulation
around 6N146E. It then extends to the east-northeast, passing north
of Chuuk and through the far northern RMI, intersecting a surface
trough with an embedded circulation near 15N166E. The trough then
pushes southeast and exits the region around 8N180. Mostly cloudy to
cloudy skies and high-end scattered to numerous showers and isolated
to scattered thunderstorms are observed along the monsoon trough
axis, particularly in the vicinity of the trade-wind trough near
141E. The monsoon trough will generally remain quasi-stationary over
the next day or so before lifting northward this late on Friday and
into the weekend. Minor adjustments will be possible along the
western portion of the monsoon trough with some movement likely being
augmented by the aforementioned surface trough as it moves westward.

A monsoon surge is located the Equator around 146E to the northeast
and ends east of Weno, Chuuk and west of Pohnpei. An area of numerous
showers and isolated thunderstorms are observed affecting portions
of Pohnpei and Chuuk States. This surge and unsettled conditions are
expected to remain generally stationary over the next day or so.

SURFACE TROUGHS...
A surface trough is located near 141E from 17N to 6N this morning.
The feature passed through the Marianas yesterday and brought
scattered to numerous showers and isolated to scattered thunderstorms
and this continues today. The trough will propagate westward over
the next day or two and continue to bring unsettled weather as it
pushes to the west.

TRADE-WIND TROUGHS...
A trade-wind trough is located around 170E with an embedded
circulation near 15N166E. Scattered showers are observed along the
trough and this feature will generally drift westward and potentially
interact with the monsoon trough during the next few days. We will
continue to monitor this feature as it propagates westward.

$$

Whisnant