413
AXPQ20 PGUM 150138 CCA
TWDPQ

Tropical Weather Discussion...CORRECTED
National Weather Service Tiyan GU
1138 AM ChST Sat Jun 15 2024

Corrected typo related to direction in TUTT section.

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...

SURFACE TROUGH...
A surface trough extends from across the Philippines and enters
western Micronesia around 8N130E and passes south of Palau near
6N134E as it continues to EQ143E. Scattered showers extends from
southwest of Palau, northeast to Yap State and finally south of
Guam, supported by the upper-level divergence associated by the TUTT
west of the Marianas. The surface trough looks to linger in far
western Micronesia for at least the next couple of days as winds
remain on the lighter side as Palau and Yap remain in this early
transitional phase.

TRADE-WIND TROUGHS...
The ITCZ has fragmented into a series of trade-wind troughs and weak
convergence as scatterometer data no longer shows southeasterly
winds north of the equator west of 180. One trough is passing through
Chuuk and extends northeast back towards Pohnpei, while another
trough is currently between Kosrae and Majuro with trade convergence
extending eastward passing south of Majuro and then 8N180. Along both
troughs scattered showers and isolated thunderstorms are developing,
mainly near Chuuk Lagoon and east of Pohnpei along the first trough,
and between Kosrae and Majuro with the second trough, with showers
then extending along the convergence, passing south of Majuro and up
to 8N180. The troughs will continue to drift westward, with the
trough near Chuuk moving towards Yap and Palau, while the trough
between Kosrae and Majuro will move into Kosrae, increasing showers
across Kosrae tonight. Convergence east of Majuro will continue to
support scattered showers around the Marshall Islands through at
least Sunday.

TUTT...
The primary upper-level low is now located near 18N142E as
it continues to drift west-northwest and away from the Mariana
Islands, Convection remains limited near the center of the low and
even over the Marianas where the upper-level divergence associated
with the TUTT is currently located, with satellite imagery showing a
mid-level deck of altocumulus clouds over the Marianas with isolated
towering cumulus trying to develop but quickly being sheared by
upper-level winds. A second TUTT low is entering the region from
across the Date line and is located near 15N179E. Showers and
thunderstorms can be seen along the Date Line, east of the TUTT and
under the upper-level divergence generated by the TUTT, and generated
by the trade convergence discussed in the trade-wind trough section
above, from about 16N to 6N. Both TUTT lows will continue to drift
west-northwest. The Marianas is expected to see cloud cover
decreasing Sunday while the potential for thunderstorms and showers
will start to increase for Wake Island and the northern Marshall
Islands as the second TUTT low moves near or south of Wake Island
over the next couple of days.

$$

Schank