514
AXPQ20 PGUM 232358
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
958 AM ChST Sun Aug 24 2025

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...
A broad, weak monsoon disturbance, Invest 93W, is centered near 9.2N
130.5E. 93W is drifting slowly west-northwest. Several bands of
scattered to numerous showers and isolated thunderstorms are found
around 93W, from south of the equator northward to near 17N, from
the Philippines eastward to 137E. 93W is expected to move northwest
toward Leyte and Samar in the Philippines as it slowly strengthens.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough extends east-southeast from the Philippines,
across 130E near 9N to Invest 93W. It then extends east to end south
of Yap Proper near 9N139E. A band of convergence north of the trough
is generating scattered to numerous showers and isolated
thunderstorms north of Yap Proper, west of the CNMI. As 93W moves
northwest over the next couple of days, it will drag the monsoon
trough farther north. The eastern extend of the monsoon trough looks
to spread a little farther east, possibly into western Chuuk State.

TRADE-WIND AND SURFACE TROUGHS...
A weak, disorganized circulation is seen west of Weno, Chuuk,
centered near 8N147E. A surface trough extends west from the
circulation to end just east of Weno near 8N153E. The western extent
of the ITCZ is interacting with the circulation and trough to
generate scattered to numerous showers and isolated thunderstorms
just north of Weno to near Eauripik. The trough and weak circulation
look to slowly drift northwest over the coming days with little
change in intensity.

A trade-wind trough is found just east of Pohnpei, extending north
from near 7N159E to end near 12N160E. This trough is interacting
with the developing ITCZ to produce scattered showers and isolated
thunderstorms north to northeast of Pohnpei. The trough will
continue to move west-northwest, interacting with the ITCZ to bring
increased convection to Weno, Chuuk over the next couple of days.

Another trade-wind trough is seen south of Kosrae, extending
northeast from near 1N160E to end near 4N165E. Scattered showers and
isolated thunderstorms are found just east of Nukuoro and
Kapingamarangi to Kosrae. This trough will continue to move slowly
northwest with little change in intensity over the next couple of
days, likely interacting with the ITCZ near Pohnpei.

The last trade-wind trough is seen just east of Majuro, extending
north-northeast from near 4N171E to end near 14N176E. Scattered
showers and a few thunderstorms are found just south of Majuro where
the trough is interacting with the weak ITCZ. Farther north,
scattered showers are found along the trough. The trough will
continue to move west with little change in intensity over the next
few days, maintaining increased convection along the developing
ITCZ.

TRADE-WIND SURGE...
A trade-wind surge is seen over the northern Marshall Islands from
near 159E to beyond the Date Line between 9N and 18N, with near-gale
to gale force winds seen near the Date Line. The surge is expected to
weaken as it retreats east over the coming days.

TUTT...
The TUTT enters the area from a cell centered near 25N180, extending
southwest to southeast of Wake Island near 18N169E, then turns
west-northwest, passing through another weak cell centered near
21N159E to 25N140E, then it hugs 25N to beyond 130E. A large area of
divergence associated with the TUTT is producing numerous showers and
isolated thunderstorms north of Wake Island, north of 22N from 161E
to 173E. Scattered showers and isolated thunderstorms are found in a
south of the second TUTT cell. The TUTT looks to remain quasi-
stationary as the cells slowly drift west.

OTHER SYSTEMS...
A surface ridge has developed across the Marianas and extends south-
southwest to end at the equator near 139E. This ridge is promoting
fair weather across the Marianas and Yap State, west of Eauripik.
This ridge is expected to weaken over the next day or two, remaining
quasi-stationary.

...ITCZ...
The ITCZ stretches west, crossing the Date Line near 8N, passing just
south of Majuro, where it turns west-northwest, passing north of
Kosrae, Pohnpei and Weno. It then turns west-southwest to end just
south of Eauripik. Mostly isolated to low-end scattered showers are
found along the ITCZ except where surface troughs are interacting
with it, as described in the trade-wind and surface trough section
above. The ITCZ is expected to continue to strengthen over the
coming days as it meanders north and south over the region.

$$

Kleeschulte