192
AXPQ20 PGUM 130019
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1019 AM ChST Wed Aug 13 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 AND MONSOON DISTURBANCES...

The tropical circulation near Majuro at 9N170E has shown itself
today. As suspected, it`s dislodged itself from the mid level
circulation and convection, to reveal it`s nothing more than a
tiny circulation and poses no threat for development.

...OTHER WEATHER SYSTEMS...

TRADE-WIND TROUGHS...
All of the troughs mentioned below will continue westward with
some nocturnal flare-ups the next few days, but aside from the
troughs near the equator and Kwajalein, little convective
development is anticipated due to weak winds and resultant
convergence.

A trough in the trades has developed today, extending from north
of Yap to west of the CNMI, then north to 25N150E. This feature
is located in a light wind pattern with little convergence. Most
of the convection, in a scattered form, is due to the TUTT
overhead.

East of the Marianas, a convectively-void trough extends north
along 150E from northwest of Chuuk to east of Pagan. Here too,
weak winds and resultant negligible surface convergence from
north of Yap to 20N is providing little lift for convection. North
of there, some increase in surface convergence is allowing a few
showers to develop.

Farther south, a trough is located along 147E from the equator to
5N. Widespread cloud cover, decent surface convergence, and
seasobably-high moisture values are fostering fairly widespread
convective development.

Northeast of there, another trough in the trades is located north
of Pohnpei, from 9N157E to west of Wake Island near 19N171E, then
northward to 23N171E. Most of the convection and surface
convergence is located along this axis north of 15N, where the
convergence and effects from the TUTT are fostering more
convective development.

To its southeast, a trough stretches from east of Kwajalein to
16N173E. Convergence is strongest between 10N and 13N near 1270E,
where 850 and 500mb vorticity is helping foster convective
development, with the remainder of the trough convectively-free.

Finally, a trough extends from east of Kosrae to Majuro. Here too
surface observations and a near calm ocean surface reflecting the
sun signifies light winds and little surface convergence with no
convective development.

TUTT...
Today the TUTT extends from 25N180 to a TUTT cell southeast of
Wake Island near 16N176E, then northwest to a TUTT cell northwest
of Wake Island/NE of the CNMI at 24N156E, then southwest to a TUTT
cell at 18N135E, before ending at Typhoon Podul near Taiwan.

Over the next few days, the TUTT southeast of Wake Island looks to
strengthen, with the cell northwest of Wake Island continuing
west. The cell west of the Marianas approaches Saipan as a ridge
builds between it and Podul. Convection will continue to be found
near these cells and along the connecting axises.

$$

Doll