518
AXPQ20 PGUM 150052
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1052 AM ChST Sun Jun 15 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...

None.

...OTHER WEATHER SYSTEMS...

TRADE-WIND TROUGHS...
There are several trade-wind troughs seen across the region. The
first trade-wind trough is found northwest of Palau, extending
north-northeast from 7N130E to 13N133E. Enhanced convergence found
near and east of the trough is producing scattered showers northwest
of Palau, well west of Yap Proper. This trough will move beyond 130E
within the next 12 hours.

The next trade-wind trough is seen southwest to just west of Weno,
Chuuk, extending northeast from near 2N147E to near 7N151E. Scattered
showers and a few thunderstorms are found along and west of the
trough over western Chuuk and eastern Yap States. The trough will
continue to move west over the next few days, likely interacting with
a band of trade-wind convergence seen south of Yap Proper and Ngulu.

There is a series of three weak trade-wind troughs that are
interacting with the ITCZ. The first of these troughs is seen
between Pohnpei and Kosrae, stretching north from near 2N161E to
7N161E. Scattered showers and isolated thunderstorms are found along
a narrow band west of the trough toward Nukuoro. This trough is also
helping to enhance the convergence on the western end of the ITCZ.
The next of these troughs is found east of Kosrae, extending
northeast from near 2N163E to 5N167E. The interaction between this
trough and the ITCZ is generating numerous showers and isolated
thunderstorms across Kosrae, while enhancing convergence to the east
of the trough. The last of these three troughs is found east of
Majuro, stretching north-northeast from just north of Tarawa near
2N172E to near 7N174E. Scattered showers and a few thunderstorms are
found with this trough. The three troughs will continue to move west
over the coming days, enhancing convection along the ITCZ as they
progress.

TUTT...
The TUTT enters the area near 25N175E, extending southwest to a TUTT
cell centered near 19N161E. Enhanced divergence north of the TUTT
and circulation is fueling a few areas of scattered to numerous
showers and isolated thunderstorms north of Wake Island, well east of
Minami ToriShima. A surface ridge is seen under this area of
divergence with indications that weak troughs may be embedded in the
ridge that are enhancing the convection. This area of divergence is
expected to weaken over the next couple of days as the TUTT continues
to slowly weaken. To the south of this portion of the trough, speed
divergence is generating a narrow band of scattered showers and a
few thunderstorms from 14N159E to south of Wake Island near 16N166E.

The TUTT then continues west to beyond 130E near 18N. Only spotty
clouds, showers and a couple of thunderstorms are found along this
portion of the TUTT.

OTHER SYSTEMS...
An east-southeastward oriented trough extends from a weak
circulation centered near Mindanao across 130E near 7N to end near
5N134E. Scattered to numerous showers are found along this trough
west through south of Palau. A band of trade-wind convergence is seen
extending farther east-southeast from the trough to near 4N140E,
producing scattered showers southeast of Koror, Palau and south of
Ngulu. These features and associated convection will continue to
drift west-northwest over the next few days.

A band of trade-wind convergence is found south of Guam, stretching
east from near 11N141E to near 11N154E is generating scattered
showers along the band. This feature looks to drift west and slowly
weaken over the next few days.

A weak circulation is centered northwest of Minami ToriShima,
centered near 25N151E with a trough extending south from the center
to end near 20N151E. Scattered to numerous showers and isolated
thunderstorms are found with the circulation and trough eastward to
Minami ToriShima. This circulation and trough will drift northeast
and weaken over the coming days.

...ITCZ...
A broad, weak ITCZ enters the area near 4N180, becoming stronger and
more organized farther west, south of Majuro, to end south of
Pohnpei near 4N158E. Scattered showers and a few thunderstorms are
found with the ITCZ east of 173E. Farther west, three trade-wind
troughs are interacting with the ITCZ to generate scattered to
numerous showers and isolated thunderstorms form well south of
Pohnpei, across Kosrae to 173E. The ITCZ looks to remain active, with
trade-wind troughs enhancing convection as they travel across the
region over the coming days.

$$

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