209
AXPQ20 PGUM 050011
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1011 AM ChST Thu Jun 5 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 92W is centered west of Yap Proper and northeast of the
main islands of Palau near 9.6W 136.5E. Currently, 92W is rated a
sub-low, meaning development into a significant tropical
development is not expected in the short term. Moderate to deep
convection is occurring near 92W across Yap Proper and the main
islands of Palau. Pockets of convection are also occurring along a
surface trough extending north of 92W up to 19N132E. 92W will
continue to become better organized as it works northwest,
possibly strengthening into a tropical depression or tropical
storm as it exits the AOR by the weekend and approaches the
northern Philippines.


...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough extends east from the Philippines, entering the
AOR near 12N130E, passing through Invest 92W west of Yap, then
turning southeast, passing in-between Yap proper and the main
islands of Palau and crossing the equator near 143E. Pockets of
moderate to deep convection are occurring along the monsoon
trough and within the monsoon surge south and west of the trough.
Moderate to deep convection is occurring across much of the
Republic of Palau and western Yap state. The monsoon trough will
be pulled north as 92W continues to pull west-northwest towards
the Philippines. This will lead to south to southwest flow over
Palau and Yap for the end of the week into the weekend, bringing a
prolonged period of unsettled weather with associated heavy
showers and gusty winds.

TRADE-WIND TROUGHS...


Several trade-wind troughs are passing through the AOR. A trough
of note is situated east of the Marianas, beginning near 21N148E
and extending south, ending northwest of Chuuk Lagoon near 8N148E.
Pockets of showers are occurring along and north of the trough,
mainly over the open ocean. This disturbance will continue to
drift west over the next couple of days and dissipate.

Another trough is approaching Wake Island, extending south from
25N172E and ending near 16N168E. Pockets of showers are occurring
within the trough as it works west towards Wake Island.


TUTT...
The Tropical Upper-Tropospheric Trough extends from an upper-low
east of the Date Line, entering the AOR near 13N and stretching
northwest south of Wake Island through a TUTT low near 19N154E,
then extending southwest across the Marianas and ending near
13N138E north of Yap proper. The TUTT is interacting with several
surface troughs and helping bring moderate to deep convection,
directly west Marianas and north of Yap proper, as well as north
and west of Chuuk Lagoon. Spotty showers are occurring elsewhere
within the TUTT, with a pocket of convection underneath the TUTT
low northeast of the Marianas. The TUTT low looks to shift
westward, lifting north-northwest of the Marianas this coming
weekend, helping enhance showers and thunderstorms. Another TUTT
low looks cross the Date Line and approach Wake Island over the
weekend, helping enhance showers and thundestorms as well.

...ITCZ...
The Inter-Tropical Convergence Zone (ITCZ) begins east of the
Date Line and enters the AOR near 8N, extending west-southwest
through Majuro and south of Kosrae through a circulation centered
near 2N162E, ending south of Pohnpei near 2N156E. A large area of
deep convection is occurring near and east of the circulation,
from south of Pohnpei and Kosrae to southwest of Majuro, generally
south of 5N and inbetween 157E to 172E. Pockets of showers are
occurring through Majuro and east past the Date Line. The ITCZ
will continue to drift north and west with showers and
thunderstorms building into Kosrae and Pohnpei states today and
tonight. The ITCZ is expected to become poorly-defined by the
weekend. The circulation is slowly drifting west, along and north
of the equator and south of 5N, bringing showers and
thunderstorms to southern Pohnpei and Chuuk states through the
weekend.

$$

Slagle