593
AXPQ20 PGUM 300109
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1109 AM ChST Sun Mar 30 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...
A broad trade-wind trough stretches from EQ155E to 4N 157.5E,
east-northeast to 7.5N 161.6E, bisecting Pohnpei and Kosrae,
continuing northeast to near Kwajalein. Scattered showers and an
occasional thunderstorm continue to accompany this feature marking
the leading edge of some enhanced surface convergence, which
looks to continue westward the next several days.

OTHER SYSTEMS...
An old shear line that regenerated a couple days ago continues to
slowly sink south across portions of the forecast area, currently
stretching from east of Wake Island at 19N180, continuing west-
southwest to 14N170E, then to 13N160E, to 13N150E, before fizzling
out over central Guam. However, a mid-level disturbance just
southeast of Guam is enhancing lift, while interacting with the
remnant shear lines over Guam and Saipan to produce mostly cloudy
skies and scattered showers across much of the Marianas, with
these showers occasionally producing wind gusts to 30 kts.

Another shear line stretches from 20N180 to 16.7N 170E in a west-
southwest orientation, continuing west in an occasionally wavy
form to 15.7N 160E, to Saipan.

A third remnant shear line stretches from 17.7N 170E, to just
south of Wake Island, continuing west in another wavy form to
Pagan in the northern CNMI.

These shear lines will remain quasi-stationary over the next 48
hrs or so, eventually dissipating. Until then, at least widely
scattered showers remain possible.

...ITCZ...
An ITCZ fragment stretches from EQ145E to 3.3N130E. This feature
is acting to enhance surface convergence amid a seasonably-moist
atmosphere, characterized by PWATs near 2.5 inches. Fairly robust
convection is developing along this feature, especially across
southern Palau near Helen`s Reef. The latest GFS Galvez-Davison
Index (GDI) suggests this ITCZ will strengthen as it reorientates
itself, stretching from Helen`s Reef to just south of Chuuk,
through Pohnpei and Kwajalein, to north of Majuro in the next 72
to 84 hours. This should foster increasing convective development
as it does so.

$$

Doll