388
AXPQ20 PGUM 170109
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1109 AM ChST Mon Aug 17 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...

TROPICAL AND MONSOON DISTURBANCES...
Invest 92W, located near knee (northwest of Pohnpei/well
northeast of Chuuk). It continues to retain a "Low" rating from
JTWC. Similar to the last several days, it continues to move
slowly west, with an estimated forward speed of 2 knots. Also in a
similar fashion, most of the convection is tied to the western
semicircle of the disturbance. The bulk of the models want to lift
this northwest over the next 48 hours, but given observational
trends we believe this system will continue its westward drift for
another 48 to 72 hours. This will allow for locally heavy showers
with isolated bursts of fresh to strong winds gusts to continue
across Chuuk and Pohnpei States, and to a lesser extent now,
Kosrae. Some further strengthening/organization is probable with
92W over the next few days, as it remains in a favorable
environment of low wind shear and warm to very warm SSTs.

Further northwest, we have Invest 94W, located near 18N133E
(northwest of Yap), in the open Philippine Sea. It continues to
remain as a "Sub-Low" rating, which may continue for at least
another 36 to 48 hours, possibly longer. This looks more like a
monsoon eddy in the flow, with just shallow convection near its
LLCC. This system is expected to meander in the area, eventually
picking up speed and heading northwest, likely out of Guam`s AOR
in 72 hours.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough enters Guam`s AOR between 10N and 20N at 130E.
It then turns east-southeast near Invest 94W, passing over Guam
and the southern CNMI before linking up with 92W. From there, the
monsoon trough axis passes through a col northwest of
Kwajalein/south of Bikini Atoll. It then continues east-southeast
through Majuro, exiting Guam`s AOR near 7N180. South of the
trough, mainly gentle to moderate west-southwesterly flow
dominates the region, locally backed near 92W and 94W. As one
would expect, high PWATs above 2.5 inches are common, with areas
of scattered showers and isolated thunderstorms continuing, mainly
along and just south of the trough axis. This trough
alignment/positioning looks to remain in place the next several
days, augmented locally in time as 92W and 94W progress along it.

SURFACE TROUGHS...
A surface trough extends northeast from 94W. to near 24N141E. No
significant convection is observed with the trough itself, as it`s
tied more to 94W and good surface convergence along the south
side of it. This pattern looks to continue the next 72 hours, at
which time most, if not all, of the trough will exit Guam`s AOR.

$$

Doll