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AXPQ20 PGUM 081134 AAA
TWDPQ

Tropical Weather Discussion...UPDATED
National Weather Service Tiyan GU
934 PM ChST Wed Oct 8 2025

Updated for new tropical cyclone in the region.

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 CYCLONES...
A newly formed Tropical Depression Nakri (29W), formerly known as
JTWC`s Invest 95W, is centered near 20N138E well northwest of the
Marianas. This system is moving north-northwest at 8 mph, with
maximum sustained winds at 30 mph near the center of the closed Low-
Level Circulation (LLC). This system is expected to continue to move
in this general direction toward Okinawa, Japan, followed by a slight
acceleration in forward speed by Thursday. In addition, the system
is expected to slowly intensify on approach toward the Ryukyu chain,
possibly becoming a tropical storm early Thursday morning. This
system is not expected to have any direct impact to any islands in
NWS Guam`s Area of Responsibility (AOR).

For more information please refer to bulletins from the Joint
Typhoon Warning Center under WMO header WTPN31 PGTW and from the
National Weather Service under WMO header WTPQ31 PGUM.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough enters Guam`s AOR at 15N130E and extends to
Invest 95W. South of this line, southwesterly winds are bringing
scattered showers to the open ocean north of Koror and Yap, and
west of the Marianas. These features will continue to lift
northwest the next few days with an overall similar pattern.

TRADE-WIND TROUGHS...
A very long surface trough stretches from EQ145E to Chuuk,
continuing northeast to 18N160E (west-southwest of Wake Island),
ending at 22N165E (north-northwest of Wake Island). Scattered
showers and a few thunderstorms are occurring from the equator to
5N along the trough due to increased surface convergence, and from
13N to 22N as this portion of the trough interacts with a mid-
latitude trough thats dropping south across the tropics. A
similar convective behavior is expected through the weekend as it
continues to head west.

TUTT...
A trough dropping south from the mid latitudes stretches from
25N180 where it enters Guam`s AOR, through Wake Island to Saipan,
ending just west of there at 17N142E. Scattered showers and a few
thunderstorms continue to develop along and south of this feature
due to divergence.

This trough is transitioning into a TUTT, with both the GFS and
ECMWF forecasting a cell to form south of Wake Island in 48 hours,
drifting south to between Bikini Atoll and Kwajalein by Friday,
with the TUTT axis stretching west to a weaker cell that`ll try to
develop somewhere near Guam. This also occurs as a fairly stout
upper ridge builds from near Taiwan east to the Date Line between
20N and 30N. The increased gradient allows the winds to increase
between these features due to a tightening pressure gradient. This
signals a potentially interesting period from the Marianas
eastward for the weekend and through at least the middle of next
week, possibly longer. Stay Tuned!

...ITCZ...
The ITCZ is more distinguishable today as it attempts to reform.
Currently it stretches from Chuuk eastward to the Date Line.
However, this feature itself is void of any appreciable
convection, with embedded troughs being the focus for any
increased convective potential. This looks to be the case through
the weekend and into early next week.

$$

Morning Issuance: Doll
Update: Montvila