368
AXPQ20 PGUM 170134
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1134 AM ChST Fri Apr 17 2026

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 CYCLONES...
Typhoon Sinlaku continues to move through the far northern
Mariana Islands. At 1000 ChST, Sinlaku was located near 19.5N and
145.4E, about 55 miles north-northwest of Agrihan and about 305
miles north of Saipan. Typhoon force winds extend outward from the
center up to 85 miles. Tropical storm force winds extend outward
from the center up to 270 miles to the northeast and up to 235
miles elsewhere. Latest altimetry data shows hazardous seas of 15
feet near Guam, increasing northward and reaching to around 30
feet near the far northern Marianas. Sinlaku is moving north-
northeast at 7 mph and is expected to pass north of Agrihan,
maintaining this general course with a slight increase in forward
speed through Saturday. Sinlaku is producing dense cloud cover and
widespread showers over the far northern Marianas with weaker
rainbands well to the south, across Guam, Rota, Tinian, and
Saipan. The eye continues to be less defined and drier air is
wrapping around to the west-southwest of its center. Heaviest
rainbands are focused along the southeast to north sides of the
system. As this weakening trend and its north-northeast trajectory
continue, Sinlaku may become extratropical sometime Sunday.

Typhoon Warnings have been cancelled for Rota, Tinian, and Saipan,
but remain in effect for Alamagan, Pagan, and Agrihan in the CNMI
and the adjacent coastal waters.

For more information please refer to bulletins from the Joint
Typhoon Warning Center under WMO header WTPN31 PGTW and from
the National Weather Service under WMO header WTPQ31 PGUM.

...OTHER WEATHER SYSTEMS...

SURFACE TROUGHS...
A surface trough extends southwestward from Typhoon Sinlaku,
passing just northwest of Yap and Palau and extends beyond 5N130E.
A broad area of northerlies continues to entrain drier air into
the region, leading to patchy showers along this feature. This
trough will follow the motion of Sinlaku, as it moves north-
northeastward, leaving behind a light and variable wind pattern
across far western Micronesia over the weekend, then a transition
to a light to gentle trade-wind pattern next week.

In the wake of Typhoon Sinlaku, several troughs are moving across
a broad region from 10N to 25N and between 160E to the Date Line.
A SW to NE oriented trough and trailing trade-wind convergence is
generating an area of scattered showers and a few thunderstorms
across the north Marshalls. Meanwhile, patchier showers are seen
across a series of troughs near and northeast of Wake. Over the
next few days, slight west to northwest shifts are expected, but
will be limited to the dominant steering motion of Sinlaku and an
eastward moving front that is expected to move north of Wake.

...ITCZ...
An Intertropical Convergence Zone (ITCZ) extends into the region
near 3N180 and stretches across the southern Marshalls to end near
4N171E. Scattered to numerous showers and isolated thunderstorms
are seen along this feature. Over the next few days, a fragmented
ITCZ pattern builds eastward into the region, with embedded
trade-wind trough helping spread showers northward.

$$

Cruz