404
AXPQ20 PGUM 280102
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1102 AM ChST Sat Jun 28 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...
Invest 97W is located near 15N138E (due west of the Marianas). A
circulation associated with this system is difficult to identify on
satellite imagery. Scattered to numerous showers and isolated
thunderstorms are observed in all quadrants expected the southwest.
Little change is expected in intensity or location over the next few
days.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough enters the region near 18N130E and extends
southeastward to 9N146E to the south of Guam. Convection is found
within 225 miles on either side of the trough axis near the western
end, then within 325 miles near the east end. Invest 97W is embedded
in this trough. Pockets of moderate to deep convection are observed
and thunderstorms were found along the northern edge leading up to
97W. This feature is expected to remain quasi-stationary and
maintain its intensity over the next few days.

TRADE-WIND TROUGHS...
5 trade-wind troughs are observed. The First enters the region near
12N180 and expected southwest through Majuro and continues southwest
to EQ164E to the south of Kosrae. Convection has been observed within
150 miles of the through axis. Pockets of deep convection are
observed, mostly to the south of Jaluit and southwest of Ebon.
Showers associated with this trough are expected to diminish as the
day progresses. The trough will continue to move westward over the
coming days as it slowly weakens.

The second, third and fourth troughs are fairly close together and
fairly weak. The second trough is located to the north west of Kosrae
and extend northwest to near Pingelap. The next trough is just east
of Pohnpei and extend north to about 11N159E. The fourth trough is
between Chuuk and Pohnpei, with the axis located near 11N156E and
extending southward to 5N155E. All three troughs have isolated
pockets of convection and one noticeable pocket of deep convection
near Pingelap. The pocket of deep convection is further enhanced
low-level convergence. These troughs are expected to move westward
and diminish over the next few days.

The last trough is located near 11N140E and extends southwestward
over Yap and Palau, then farther to the southwest to near 3N131E.
Pockets of deep convection can bee found within 130 mile of the
trough axis. Thunderstorms have been observed to the east of Palau.
This is trough is expected to move westward over the coming days,
increasing convection across Palau.

TUTT...
The TUTT enters the region near 25N156E and extends south to near
17N151E, then turns west to near 17N137E. The TUTT then turns west-
northwest to end near 24N130E. A TUTT cell can be found along this
axis near 21N152E. Convection is just starting to develop around the
TUTT cell. The TUTT and TUTT cell is expected to remain quasi-
stationary and the cell is expected to gradually intensify over the
next few days.

$$

Bowsher