522
AXPQ20 PGUM 180202
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1202 PM ChST Tue Aug 18 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...

Delayed issuance to await new rating for 92W per coordination with
JTWC

TROPICAL AND MONSOON DISTURBANCES...
Invest 92W, located near 8N155E (northwest of Pohnpei/east-
northeast of Chuuk), is trying to get its act together, with some
improved convective signature across the southern half of the
system. This has led to an increase in rating, with JTWC now
placing a medium rating on it, meaning formation of a tropical
cyclone (tropical depression or stronger) is likely, but beyond 24
hours. It continues to remain quasi-stationary, drifting west to
southwest at 5 mph. The environment is marginally favorable for
further development, as about 15 to 25 knots of easterly wind
shear is fighting the tropical disturbance, as is some dry air on
the north to northeast flank of the system.

Additionally, the vorticity centers aloft are not co-located with
the LLCC (Low-Level Circulation Center). With all of this in
mind, 92W will likely continue to show a slow development pace for
the next 48 to 72 hours, with the real question being when will
it start to track north-northwest (roughly a 340 heading).
Questions also remain as to whether it`ll take a westerly turn
with time towards the end of the week, as a subtropical ridge
strengthens to its north, stretching from China eastward to just
north of Iwo To and Minamitorishima, and east-northeastward. Stay
tuned!


...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough stretches from Invest 94W (which is now located
just west of Guam`s AOR at 21N132E), extending southeast to Guam
where a col is located, before continuing southeast and linking up
with 92W. The trough then continues east-southeast through a col
between Kwajalein and Majuro, passing through Majuro, before
exiting Guam`s at 8N180. West to southwesterly flow of 10 to 20
knots is centered between ~7N and the trough axis, with pockets of
scattered shower and isolated thunderstorm development continuing.
In general, this trend is expected to continue the next few days,
with the exception being near 92W. Here, convective coverage and
intensity will gradually increase as 92W strengthens, while it
also helps to locally augment trough orientation.

$$

Doll