787
AXPQ20 PGUM 150212
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1212 PM ChST Wed Oct 15 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 96W does have a mid-level circulation and is producing a
surface trough under it. The circulation is located near 12N143E, and
the axis is located near 17N146 and extends southwest through the
Marianas to 9N141E near Sorol. Convection associated with this
feature is becoming light to moderate, with the heaviest showers
between Guam and Sorol. An upper-level trough is aiding in
thunderstorm development. This feature is expected to continue moving
west into the Philippine Sea and into more favorable conditions.

There is a tropical disturbance to the west of Kosrae near 6N162E.
This feature is clashing with a fragmented ITCZ, and the embedded
troughs in the region. Moderate to deep convection is associated with
this feature along the eastern sector of the disturbance. This
feature is expected to become an open surface trough over next day or
so as it moves westward into Pohnpei State.

...OTHER WEATHER SYSTEMS...

TRADE-WIND TROUGH...
A trough is near the north end of Invest 96W at 18N147E (to the east
of Alamagan) and extends northeast to 23N153E (southwest of
Minamitorishima). Moderate convection is associated with this
feature, and extend about 150 nautical miles from the trough axis.
An upper-level trough is aiding in the production of thunderstorms
near Minamitorishima. This feature is moving in a northwest
direction and is expected to maintain its intensity over the next few
days.

TUTT...
The TUTT enters the region near 25N177E and extends southwest into a
TUTT cell 16N172E (southeast of Wake Island). The TUTT continues
south to near 8N167E near Kwajalein. Light to moderate convection is
associated with the TUTT cell along its eastern sector. Along the
outer peripheries, the cell is producing isolated to scattered
thunderstorms. This feature is expected to maintain its current
intensity and move westward over the coming days.

OTHER SYSTEMS...
An upper-level trough enters the region near 25N150E and extends
southwest until it exits the region at 14N130E. This trough passes to
the west of the Marianas. This upper-level trough is aiding the
trade-wind trough and Invest 96W. This feature is being squeezed by
two upper-level highs and is expected to evaporate over the next day
or so.

...ITCZ...
A fragmented ITCZ with embedded troughs is clashing with the
tropical disturbance near Kosrae and is hard to tell where the
disturbance ends and the ITCZ begins. The ITCZ enters the region near
6N180 and extends northwest to near Kwajalein. Then, ITCZ turns
southwest to meet up with the tropical disturbance near 6N162E near
Kosrae. Moderate to deep convection with heavy rains are associated
with this feature. Convection extends about 100 miles north of the
axis and about 350 miles south of the axis. The ITCZ is expected to
fill in over the next few days and maintain its intensity.

$$

Bowsher