124
AXPQ20 PGUM 070218 CCA
TWDPQ

Tropical Weather Discussion...CORRECTED
National Weather Service Tiyan GU
1218 PM ChST Fri Aug 7 2026

Corrected invest number

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 developing circulation has been listed as Invest 98W, located
near 20N144E, which is just west of the Maug Islands in the
northern-most portions of the CNMI. This system has been
partially responsible for the persistent shower and thunderstorm
development west of the Marianas, which is discussed below. A
closer inspection of 98W (rated as "Sub-Low" from JTWC, shows a
compact, small circulation elevated slightly above the surface.
Persistent mind to high level cloud cover makes it difficult to
discern low-level cloud movement/wind flow near the LLCC
attempting to develop, but enough thinning is evident when zoomed
in locally to this area, a tight cyclonic circulation is apparent,
but again, it has a slightly elevated "look" to it.

With that said, the environment is characterized by warm to very
warm SSTs of 85F to 86F, and low vertical wind shear as it`s
located near the tail-end of a high pressure ride axis. A
subsequent col is located just southeast of 97W, as a surface
trough enters Guam`s AOR near Iwo To, stretches to 98W, then
curves northeast to Minamitorishima, before linking up with what
is now TD 14W (formerly Invest 96W), north of Wake Island and
outside Guam`s AOR. As such, given the nearby and brief emergence
of the surface trough/tail end of the ridge axis, the low wind
shear and highly-favorible SSTs should allow for a gradual, slow
evolution of an organizing LLCC through the next few days, with
the LLCC likely remaining quasi-stationary.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
The monsoon trough remains anchored in place, with the main
"belt" of it centered between 10N and 20N as it enters Guam`s AOR
at 130E from the Philippines. Here, sustained winds of 20 to 25
knots and seas of 8 to 12 feet (highest north) common. The trough
then stretches east to ~138E, where a "fork in the road" develops,
with the "left fork" turning north and then northwest as it
becomes part of the inflow into Typhoon Dolphin. The "right fork"
turns east and stretches across the Marianas in a west-southwest
to east-northeast fashion. before turning more north-northeast
after crossing 160E, passing through Wake Island, as it wraps into
Invest 96W (TCFA), which is outside of Guam`s AOR/well north of
Wake Island.

From the Marianas eastward, winds drop down into the 15 to 20
knots range from 145E to 160E (locally higher in and near
convection), with seas of 8 to 11 feet. East of 160E and north of
18N, winds become more southerly and increase into the 20 to 25
knot range, and seas of 8 to 10 feet.

As for convection, areas of scattered showers and isolated
thunderstorms are developing between 10N and 20N from 130E to
~172E. The "bulk" of the convective activity, in the form of
numerous showers and scattered thunderstorms, are centered just
west of the Marianas between 140E and 145E from 12N to 18N. Here,
intense thunderstorm development continues with cloud top
temperature eclipsing -80 deg, frequent to continuous lightning,
and scatterometer-observed winds near 30 knots.

Looking ahead, the monsoon trough looks to "hang out" between 10N
and 20N, while retreating to the west by early next week.

$$

Doll