177
AXPQ20 PGUM 080104
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1104 AM ChST Tue Sep 8 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 our Area of Responsibility (AOR) near
25N133E, extending southeast through a col centered north-northeast
of the Marianas. From there, the trough continues south-southeast
passing through a col centered near 13.5N143E before passing south
of Guam. The trough continues curving southeast to pass through a
circulation centered between Satawal, Yap and Weno, Chuuk around
8N149E before turning to the northeast and straddling 10N as
it crosses the Date Line. Bands of convection resulting in
numerous showers and isolated thunderstorms are occurring over
open waters well to the north of Yap Island and Koror, Palau. To
the east, widespread cloud cover, scattered to numerous showers,
and convection are evident south of the trough, affecting
Kwajalein and the Republic of the Marshall Islands (RMI),
including Majuro. The monsoon trough is expected to remain fairly
unchanged in intensity and location for the next few days,
potentially spinning up a monsoon disturbance in the long-range.

SURFACE TROUGHS...
A surface trough extends southwest from the circulation near
Satawal and Weno, Chuuk, centered near 5N149E, to the Equator
around 138E. Convection is strongest closer to the center. An
area of numerous showers and isolated thunderstorms was occurring
over Satawal earlier this morning which has now moved over
Eauripik of eastern Yap State. The trough will maintain its
current intensity and stretch northward as the parent circulation
also lifts to the north over the next few days.

TRADE-WIND TROUGHS...
A trade-wind trough extends from 12N155E west-northwest to
18N147E. The leading edge of the trough is allowing for pop-up
convection, scattered showers, and isolated thunderstorms well to
the east-northeast of the Marianas. This trough looks to continue
moving west and strengthen as a potential circulation approaches
from the southeast over the next day.

Another trade-wind trough is located from 12N172E extending
north-northwest to 19N169E. Shower activity is not as impressive
as the trough mentioned above with isolated to scattered showers
and short-lived convective towers concentrated near the center of
the trough axis. Over the next few days, this trough will slowly
move westward before dissipating.

$$

Mesa