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735
AXPQ20 PGUM 010101
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1101 AM ChST Tue Sep 1 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...
A monsoon disturbance, Invest 94W, remains NE of Luzon, centered
near 22.0N 132.3E, moving slowly NNW. Invest 94W remains the subject
of a Tropical Cyclone Formation Alert (TCFA) by the Joint Typhoon
Warning Center (JTWC), meaning 94W is expected to become a
significant tropical cyclone (tropical depression) within the next
24 hours. Invest 94W is seen as a broad, elongated circulation on
the latest ASCAT and 925mb analyses, embedded along the monsoon
trough. Scattered to numerous showers and scattered thunderstorms
are seen to the S of 94W where the strongest convergence exists,
with scattered showers and isolated thunderstorms found near the
center outward about 160 miles, mainly W. Conditions remain
favorable for 94W to develop as it continues to move slowly NNW.

For more information on Invest 94W and the TCFA, see bulletins
issued by JTWC under WMO headers ABPW10 PGTW and WTPN21 PGTW.

A weak monsoon disturbance, Invest 95W and the TCFA, is seen along
the monsoon trough to the E of Rota, centered near 14.1N 149.8E. 95W
remains sub-low, meaning development is not expected for at least
the next day or two. Convergence associated with 95W is generating
scattered to numerous showers and isolated thunderstorms along a
line to the N of the monsoon trough from the center of 95W to near
17N159E, to the NW of the center over the CNMI and SW of the center
to 7N143E. Invest 95W will continue moving NNW over the coming days,
likely passing through the northern CNMI as a weak disturbance,
possibly as a Tropical Depression. Invest 95W will continue to be
monitored for any indication that development will begin earlier or
for any change in expected track.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough crosses 130E near 23N, extending ESE through
Invest 94W, across the CNMI N of Saipan, to Invest 95W. It then
turns E to 15N163E where it turns SE to just N of Majuro. It then
makes another turn toward the E, crossing the Date Line near 8N. Most
of the convection associated with the monsoon trough is found with
both Invest 94W and Invest 95W. Enhanced convergence produced by
Invest 94W is generating scattered to numerous showers and scattered
thunderstorms S of Invest 94W, as mentioned above. Farther E,
convection associated with Invest 95W is seen over the Marianas and
farther E, also described above. Spotty showers are found S of the
trough, N of Weno, Chuuk and Pohnpei. From N of Kosrae to Majuro,
scattered showers are found along and just S of the trough.
Convection again becomes spotty E of Majuro. The monsoon trough looks
to remain quasi-stationary over the next few days, with little
change in intensity, except near the two invests. The invests will
pull the associated portions of the trough slowly N with a little bit
of strengthening as they slowly develop.

SURFACE TROUGHS...
A surface trough is seen to the SE of Guam to W of Weno, Chuuk,
extending SSE from near 12N146E to end near 7N148E. Enhanced
convergence W of the trough is generating scattered to numerous
showers and isolated thunderstorms between Yap and Weno, between 6N
and 12N. This trough will move ENE over the next couple of days,
possibly interacting with the monsoon trough in a couple of days,
increasing convection along the trough.

A small surface trough is seen extending SW from a weak circulation
centered NE of Wake Island near 21N168E. Scattered to numerous
showers and isolated thunderstorms are found within an area of
enhanced convergence associated with this trough. The trough and
circulation will move toward the NE over the next couple of days,
with a slight increase in intensity.

$$

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