353
AXPQ20 PGUM 012347
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
947 AM ChST Thu Oct 2 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...

TRADE-WIND TROUGHS...
The first trade-wind trough stretches from Eauripik at 6N 143E
through Ulithi before ending 1t 14N138E. Scattered showers and a
few thunderstorms are occurring along this feature from near Sorol
northward, with just a few clouds south of there. This feature
will continue west through the weekend with a similar convective
behavior.

Also emanating from Eauripik is a trough that stretches northeast
from Eauripik to between Gaferut and Satawal to 13N150E, then
turning north to 25N150E. Most of the convection is centered
immediately behind the trough between 15N and 25N and from 150E to
points east of there. This feature also denotes a sharp increase
in moisture with MIMIC water vapor imagery showing PWATs
surpassing 2.5 inches. The imagery also shows a mid to upper level
low forming near 15N150E. As a TUTT strengthens over the next few
days, convection should increase in coverage for locations further
south, with the whole trough moving west over the next several
days.

Another trough stretches from EQ147E through Chuuk to 10N57E.
Scattered to locally numerous showers with a fairly good coverage
of embedded thunderstorms are developing along this feature. The
models show a similar convective behavior will continue the next
several days as it too heads west.

Finally, a trough stretches from Namorik at 6N 168E through
Majuro to 13N177E. Widespread cloud coverage with numerous showers
and a few thunderstorms continue to develop with this feature,
which looks to be the case as it heads west the next several days.

TUTT...
Today the TUTT enters Guam`s AOR at 23N180 and connects to a cell
that`s stationary northeast of Wake Island at 22N172E, with the
TUTT axis extending southwest to a col at 14N161E, then extending
west to a cell east of Guam at 13N147E, exiting Guam`s AOR at
15N130E. Scattered convection is occurring near the cells and
along the connecting axes, with the exception being between an
upper-level high centered at 18N159E and the Guam cell. In
between these areas widespread convection is found between 15N and
25N from 150E to 155E, as this area is in a region of very good
divergence aloft.

Over the next several days the TUTT looks to maintain a similar
orientation, which is different than the forecast from the past
several days, as the models didn`t portray the formation of the
upper high to this extent., This casts a somewhat low confidence
to the TUTT forecast,

...ITCZ...
Today the ITCZ has shifted north to 10N, stretching from 176E to
the Date Line and beyond. Widely-scattered showers are developing
near this feature, which looks to be the case for the next several
days with little movement westward.

$$

Doll