808
AXPQ20 PGUM 060109
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1109 AM ChST Sun Oct 6 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...

TROPICAL DISTURBANCES...
Invest 99W is centered north of Saipan near 16.6N 145.5E. 99W is now
the subject of a Tropical Cyclone Formation Alert by the Joint
Typhoon Warning Center. A TCFA means that 99W is expected to develop
into a significant tropical cyclone within the next 24 hours. Latest
visible satellite data shows an improved convective structure with
increasing convection near the center and periphery of 99W. Invest
99W will continue to move in a northerly direction, though continued
strengthening is expected to be slow. For more information on Invest
99W, see bulletins issued by the Joint Typhoon Warning Center under
WMO header WTPN21 PGTW.

Another disturbance, Invest 90W, is centered west of the Marianas
near 15.9N 135.7E. Deep convection is seen with this disturbance well
west of the Marianas. Invest 90W will be monitored closely over the
coming days as the system and associated convection move northward.

...OTHER WEATHER SYSTEMS...

MONSOON TROUGH...
A monsoon trough extends east-northeastward from the Philippines,
crossing 130E near 13N, to Invest 90W. The trough then continues east
to end at Invest 99W. Other than the deep convection associated with
Invest 90W and 99W, mostly patchy moderate convection is seen with
the trough. The monsoon trough is expected to strengthen a bit as it
is pulled northward with Invest 90W and 99W over the next few days.

TRADE-WIND TROUGHS...
A weak trade-wind trough is seen on satellite just west of Kosrae
to just west of Kwajalein. Scattered moderate to deep convection is
seen between Kosrae and Pohnpei. This trough and associated
convection will continue to move slowly westward over the next few
days.

UPPER-LEVEL TROUGHS/LOWS...
An upper-level low is centered near Iwo To at 25N141E. A trough
extends southwest from the low to end near 20N130E. Divergence east
of the low/trough is generating moderate to deep convection near the
low center to east of the trough and low. These features are drifting
very slowly westward over the coming days.

Another upper low is seen northwest of Wake Island near 25N162E. A
trough extends southeast from the low to end near 20N170E, with a
second trough seen north of 25N. Mostly deep convection is seen north
of Wake Island between the two troughs. This convection extends east
to beyond the Date Line. These features are also drifting slowly
westward over the coming days.

$$

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