182
AXPQ20 PGUM 230111
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1111 AM ChST Sat Aug 23 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...

None.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough enters the region near 14N130E and extends
southeast to an embedded circulation just south of Palau near
6N135E, then makes a short easterly jog to near Eauripik at 7N142E.
Widespread showers and isolated thunderstorms are located mostly
around the circulation and may be heavy at times. This feature is
expected to remain quasi-stationary and maintain intensity over the
next few days.

TRADE-WIND TROUGHS...
There are 4 major trade-wind trough in the region.

The first is located near 16N141E and extends southwest to 6N135E
close to Yap Proper and the Marianas. The associated convection
makes a Y shape where the base is the trough axis and the arms are
the convergence zones on both sides of the trough. This feature is
producing scattered to widespread showers and isolated thunderstorms.
It is expected to move westward and maintain intensity over the next
few days.

The second trough is located between Chuuk and Pohnpei. near 11N158E
and extends southwest to 4N150E. Isolated to scattered showers and
isolated thunderstorms are associated with this through. A large cell
can be found near 10N157E. This feature is expected to remain quasi-
stationary and all but the cell is expected to decay over the day,
while the cell is expected to maintain intensity.

The third trough is located just west of Kosrae, 7N163E and extends
southwest to 2N160E. Convection for the most part is starting to go
into a decaying cycle, with a lingering blob of showers heading
towards Pingelap. This feature is expected to continue to decay as it
moves westward today.

The last trough is embedded in the ITCZ and is located near 12N180
and extend southwest to 4N177E, which is east of Majuro. Showers are
expected to fill in along the trough axis. More on this in the ITCZ
section. This feature is expected to move westward and maintain
intensity over the next few days.

TUTT...
The TUTT enters near 25N180 and extends westward to near 18N130E.
Most of the convection associated with the TUTT is located between
24N to 25N and from Date Line to 152E. The combination of a few
surface troughs and the TUTT providing the needed ventilation is
producing scattered to numerous shower and isolated thunderstorms
over these open waters. This feature is expected to remain stationary
over the next few days with varying intensity due to the passing
surface troughs.

...ITCZ...
The ITCZ enters the region near 5N180 and extends northwest through
Majuro, and Kwajalein and ends near 11N166E. Showers vary from
scattered to widespread with isolated thunderstorms with the most
intense showers where the trade-wind trough interacts with the ITCZ.
This feature is expected to extend westward and gradually intensify
over the next few days.

$$

Bowsher