768
AXPQ20 PGUM 230101
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1101 AM ChST Sat Nov 23 2024

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...
There are several trade-wind troughs moving across Guam`s Area of
Responsibility (AOR). There are two subtle, shallow trade-wind
troughs over western Micronesia; one to the west of Palau from
around 3N132E extending north to near 7N132E, and one east of Yap
stretching southeast from around 12N138E to near 8N143E. Scattered
showers and isolated thunderstorms can be seen near the axes of
each trough, mainly focused southwest of Palau and northeast to
east of Yap. These features will shift west over the next day or
so, bringing a few showers near Yap Proper through tonight and
later over the Republic of Palau on Sunday.

A broad trade-wind trough exists over Pohnpei State extending
northeastward from around EQ155E to the northeast of Pohnpei near
8N161E where it intersects with the Intertropical Convergence Zone
(ITCZ). Numerous showers and isolated thunderstorms are seen
spread across a broad area near the trough axis covering Pohnpei
and Kosrae. This feature and associated showers will lead the ITCZ
as it extends westward over Chuuk State in the next day or so,
moving through the rest of western Micronesia early next week.
This will bring showers through the Republic of Palau and Yap
State sometime Tuesday through Thursday, joining up with a broader
trough that looks to lift northwest across the Marianas during
midweek.

TRADE-WIND SURGE...
The overnight scatterometry data reveals a broad region of
moderate to fresh east-northeast trade winds extending west
across the Date Line, covering parts of eastern Micronesia
including the northern Marshall Islands, continuing much farther
westward across the Marianas to around longitude 138E. The area
of stronger trade winds is narrower along the westward extent
past the Marianas, between roughly 7N and 16N, and broader along
the eastern extent near the Date line, between roughly 6N and 20N.
Recent surface observations on Guam reveal moderate wind speeds
with occasional gusts to near 20 knots. Scatterometry shows the
trade wind surge is stronger farther to the east; recent Kwajalein
observations show moderate to fresh sustained wind speeds with
frequent gusts to the low 20s. Trade winds will remain steady
across the region through the weekend, increasing slightly near
the Marianas early next week as the subtropical ridge strengthens
north of the islands.

ITCZ...
The ITCZ has become more organized and extended further west since
yesterday, stretching from the Date Line near 9N180, passing
west-southwest across the central Marshall Islands before slightly
curving to the west-northwest to near Pohnpei at around 7N159E,
where it intersects with the leading trade-wind trough discussed
above. Numerous showers and isolated thunderstorms are seen along
the ITCZ, focused over the central RMI south of Kwajalein and
Wotje Atolls and north of Butaritari Atoll. Numerous heavy showers
extend westward covering Kosrae and Pohnpei where the ITCZ
intersects the aforementioned trough. There is a broad upper-level
trough located just north of these features which may be
enhancing deep convection and enabling strong wind gusts across
the area. The ITCZ will lift west-northwest over the next few
days bringing showers across the northern Marshall Islands and
over Chuuk, becoming more ill-defined early next week. An ITCZ-
like trough looks to break off and lift northwest across the
Marianas on Wednesday, increasing showers near the islands through
the latter half of next week.

$$

DeCou