843
AXPQ20 PGUM 110108
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1108 AM ChST Tue Mar 11 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 extends east-southeast from south of Palau
near 4N134E to a weak circulation along the EQ near 146E. Heavy
showers and a few thunderstorms are clustered near the circulation
well south of Yap and Chuuk, south of 5N between 140E and 150E. Both
the near-equatorial trough and circulation will stay along the
equator through the week with showers and thunderstorms persisting.
The circulation, itself, is expected to eventually weaken within the
trough.

TUTT...
The tropical upper-tropospheric trough (TUTT) still sits over Kosrae
and the Marshall Islands, though it has shown a slight eastward
motion the past 24 hours. While the TUTT will progress eastward, a
TUTT cell, or upper-level low, may briefly cut off over Pohnpei and
Kosrae states tonight and Wednesday before eventually being absorbed
by westerly flow to the north. Divergence south of the TUTT axis is
likely enhancing convection over the far southern Marshalls, helping
to produce thunderstorms and gusts to around 30 mph. While the
influence of the TUTT will wane by Wednesday, convection is
anticipated to broaden across the area with the increased activity of
the ITCZ, see below.

OTHER SYSTEMS...

COLD FRONT, SHEAR LINE...
A cold front curves southwest through 25N166E to near 17N150E, then
continues as a shear line across the Marianas near Anatahan to near
14N135E. Patchy clouds and showers are found along and up to 200
miles northwest of these features. Midday scatterometry shows winds
of 15-20 mph south of the boundaries with 20-30 mph winds to the
north. The shear line is expected to drift southward, perhaps
stalling near Saipan around midweek. The presence of the shear line
will be noted with increased cloudiness, showers, stronger gusts, and
increasing northerly swell.

ITCZ...
Showers and thunderstorms are developing east of Kosrae and south of
Majuro between 4N and 5N from 167E to 177E. Scatterometry shows a few
patches of 20-25 mph winds with gusts likely approaching around 30
mph. Latest model guidance suggests this convection is part of the
ITCZ as it acts to reassert itself in the coming days. By late week,
a more solidified band of showers and thunderstorms is expected to
span the region from Chuuk State to the Marshall Islands, mainly
between 4N and 8N.

$$

Aydlett