257
AXPQ20 PGUM 140116
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1116 AM ChST Wed May 14 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...

NEAR EQUATORIAL TROUGH...
A Near Equatorial Trough (NET) stretches southeast from Mindanao,
crossing 130E near 2N, turning eastward to end in a buffer
circulation near 1N142E. Scattered showers and isolated thunderstorms
are found along and south of the NET, with numerous showers and
scattered thunderstorms found near the NET and buffer circulation.
There are also 2 trade-wind troughs interacting with a band of
convergence north of the NET, maintaining numerous showers and
isolated thunderstorms over Palau to Yap Proper. Little change in
intensity or location is expected with the NET over the coming days,
with convection varying in coverage and intensity as other features
move through and interact with the NET.

TRADE-WIND TROUGHS...
There are several trade-wind troughs evident across the region. The
first two are seen over Palau and Yap State, interacting with the NET
and trade-wind convergence, described in their appropriate sections
above and below. These troughs are enhancing convection across Palau
and Yap, including Yap Proper. The troughs will continue to move
west over the coming days, moving out of the area Thursday into
Thursday night.

Another weak trough is interacting with the weak band of convergence
near Kosrae and over the Marshalls, to produce a narrow band of
enhanced showers between Kosrae and Majuro.

Farther southeast, a pair of troughs are interacting with another
band of convergence over the extreme southeastern edge of the area.
Most of the convergence and convection remain east of the Date Line,
however, the trough near the Date Line is expected to pull more of
the convection into the area as it cross the Date Line Thursday.

OTHER SYSTEMS...

TRADE-WIND CONVERGENCE...
There are 3 separate bands of trade-wind convergence across
Micronesia. The first, and more significant, band is seen north and
east of the NET, discussed above. This band stretches across the
equator near 147E, extending northwest to pass south of Yap Proper,
ending around Koror, Palau near 7N134E. A pair of weak trade-wind
troughs are interacting with the band to maintain numerous showers
across most of Palau into western Yap State, including Yap Proper.
The convergence looks to oscillate in intensity over the next few
days as it interacts with trade-wind troughs and the NET/buffer
circulation to the south.

The second band of convergence is found just northwest of Kosrae near
5N162E across the Marshalls between Kwajalein and Majuro to end near
10N175E. This band is now very weak, with mostly spotty showers and
patchy clouds seen along the band. The one exception is where a weak
trade-wind trough is interacting with the band between 167E and 168E,
producing scattered showers between Majuro and Kosrae. Little change
is expected with the band of convergence as it is expected to remain
fairly weak over the coming days.

The third band is newly developing to the east of Butaritari and
Tarawa. Weak trade troughs are interacting with this band of
convergence to produce enhanced convection from just east of
Butaritari and Tarawa atolls to beyond the Date Line. This band of
convergence looks to drift west over the coming days, remaining
south of 5N. Troughs traversing the area will result in pulses of
convection over the next few days.

UPPER-LEVEL TROUGH...
An upper-level trough extends from the mid-latitudes and enters the
region near 18N180 and extends west-southwest across the far
northern Marshall Islands into an upper-level low centered near
14N155E. The trough then turns southeast across Chuuk State to
end southwest of Weno, Chuuk. There is very little convection along
most of the trough`s axis due to the lack of surface features. This
upper-level trough is expected to shift eastward as it is pulled away
by stronger westerly flow in the mid-latitudes, exiting the region
by Thursday.

UPPER-LEVEL DIVERGENCE...
An area of upper-level divergence is seen south of an upper ridge
over Palau and Yap. This is enhancing convection over the region
associated with a band of convergence and the NET, discussed above.
The divergence is expected to slowly drift east as it weakens
slightly over the next few days.

$$

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