878
AXPQ20 PGUM 230058
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1058 AM ChST Thu Jul 23 2026

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 now centered near the far western edge of the Guam
Area of Responsibility (AOR) near 15.2N 130.6E. 92W is now the
subject of a Tropical Cyclone Formation Alert (TCFA) by the Joint
Typhoon Warning Center (JTWC), meaning 92W is expected to become a
significant tropical cyclone within the next 24 hours. Curved deep
convection is now evident on satellite over the western periphery of
92W, with a partially exposed Low-Level Circulation Center (LLCC).
ASCAT and satellite data also indicate that the maximum wind field
radius is decreasing, indicating the system is slowly consolidating.
Most of the convection associated with Invest 92W is seen W of 130E.
A broad area of convection, with numerous showers and isolated
thunderstorms is also seen to the S of the center, W of Palau and
Yap. Invest 92W will continue to move WNW over the next couple of
days, likely moving out of the Guam AOR later this morning or early
afternoon before becoming a Tropical Depression. For more
information on Invest 92W and the TCFA, see bulletins issued by JTWC
under WMO headers ABPW10 PGTW and WTPN21 PGTW.

Invest 93W remains very poorly organized this morning. It is
centered near 12.9N 170.1E, moving slowly W. 93W remains sub-low,
meaning little or no development is expected over the next couple of
days. Scattered showers and isolated thunderstorms are seen mainly E
of the center, where the strongest convergence is found. Invest 93W
will continue to drift W to WNW over the next few days, with little
change or slight weakening expected.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough passes through Invest 92W, extending E, through a
COL W of the Marianas, then turns SE to a weak circulation centered
just W of Pohnpei near 7N158E. The trough continues NE to Invest
93W, then turns SE to beyond the Date Line near 9N. Convection
associated with the monsoon trough is seen S of Guam where winds are
wrapping around from the NE into the weak circulation E of Kosrae.
The low-level convergence in this area is interacting with an area of
upper-level divergence to produce widespread showers and isolated
thunderstorms S of Guam between Yap Proper and Weno, Chuuk. Farther
E, scattered showers and isolated thunderstorms are found S of the
trough within the monsoon flow, S of Weno, Pohnpei and Kosrae.
Farther S, near the Equator, another band of scattered showers with
a few thunderstorms is seen in the monsoonal flow. The monsoon trough
looks to continue to fluctuate around the region with little change
in intensity over the next several days.

TRADE-WIND TROUGHS... There are two trade-wind troughs evident across
the region. The first is seen to the E of the CNMI, extending NNE
from near 14N149E to end near 20N154E. Enhanced convergence W of the
trough is generating scattered showers and isolated thunderstorms
over and E of the northern CNMI. This trough will continue to move W
over the next few days, possibly bringing increased showers to Tinian
and Saipan.

The second one is found farther E, N of Invest 93W, extending N to
end NE of Wake Island near 23N171E. An area of scattered showers and
isolated thunderstorms are seen to the ENE of Wake Island in a band
of low-level convergence where divergence aloft associated with the
TUTT is interacting with it. The trough and associated convergence
will continue to move W, with little change in intensity, pulling W
of the TUTT.

TUTT...
The TUTT enters the region near 22N180, extending W, passing just N
of Wake Island, to 20N164E, then turns SSE to a TUTT cell near
5N161E. It then continues SE to end near 10N154E. Divergence
associated with the TUTT is enhancing convection ENE of Wake Island.
The TUTT looks to remain quasi-stationary over the coming days with
little change in intensity.

OTHER SYSTEMS...
A weakening cold front enters the region near 25N160E, extending SW
to near 21N150E, then turns WNW to end just S of Iwo To near
24N141E. Cloudiness with numerous showers and isolated thunderstorms
is seen in a narrow band along the front. The front will continue to
move E over the next few days as it slowly weakens.

A band of divergence E of an upper-level trough is enhancing
convection along the monsoon trough S of Guam. The trough will
continue to move W, with the divergence weakening as the trough
moves away from the region.

$$

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