189
AXPQ20 PGUM 020136
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1136 AM ChST Wed Jul 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...

TROPICAL CYCLONES...

Tropical Depression 04W, formerly monsoon disturbance Invest 90W, is
centered near 25N147E, moving north to northwest at 9 mph. At this
time, maximum sustained winds are 35 mph near the center. Moderate to
occasionally deep convection is associated with this feature,
producing numerous showers within 150 miles north of center, and
numerous showers with scattered thunderstorms within the inflow zone
along the eastern peripheries. 04W is forecast to intensify through
tonight, possibly becoming a tropical storm as it exits the region
sometime this afternoon. No direct impacts are expected to the
Marianas or Micronesia from this storm.

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 the region near 17N130E, extending east-
southeast to 16N135E, to then extend farther to the northeast across
a large area to Tropical Depression 04W well north-northeast of the
Marianas and east of Iwo To. Numerous showers and scattered
thunderstorms are observed within 175 miles east of the trough axis,
enhanced by an upper-level low just southwest of the aforementioned
TD 04W. This feature will continue to shift northward as 04W
continues in the same trajectory.

TRADE-WIND TROUGHS...
A few notable trade-wind troughs are observed across the region. The
first one extends from the Equator near EQ142E northward across
eastern Yap State to end near Eauripik, producing scattered to
numerous showers within a large area between Eauripik and the
Equator near the 140E longitude. The second one is upstream; a broad
surface trough embedded within the Intertropical Convergence Zone
(ITCZ) extends from EQ150E northeastward across southern Chuuk State
to end halfway between Weno, Chuuk and Pohnpei. This feature is
producing scattered to numerous showers and thunderstorms from 150E
to 156E, between 6N and the Equator. These two more notable features
are expected to integrate with each other overnight, with a sharp
leading edge that may spawn a largely disorganized tropical
disturbance right before buckling against a building ridge to the
west, eventually dissipating before the weekend.

TUTT...
The Tropical Upper Tropospheric Trough (TUTT) enters the region near
24N180, extending west to 24N172E to then dip down to a TUTT cell
centered near 19N168E, and then extend farther south to end near the
Equator. Moderate convection is associated with this feature,
producing scattered showers and thunderstorms within the western
flanks of the TUTT cell over and to the south-southwest of Wake
Island. This feature is expected to meander in the general vicinity,
before dissipating under frictional forces aloft during the weekend.

...ITCZ...
The Intertropical Convergence Zone (ITCZ) enters the region near
6N180, extending west across Majuro, Kosrae, Pohnpei, through a broad
surface trough to then end at another surface trough in eastern Yap
State. Separate from the interactions with the aforementioned trade-
wind troughs, scattered to numerous showers and some thunderstorms
are observed south of Pohnpei and across much of the Marshalls. This
feature is expected to shift slightly northward, before transforming
into a feeder for the aforementioned tropical disturbance that may
attempt to form in eastern Yap State, before dissipating during the
weekend and shifting southward toward Papua New Guinea.

$$

Montvila