Tropical Weather Discussion
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275
AXPQ20 PGUM 280113
TWDPQ

Tropical Weather Discussion
National Weather Service Tiyan GU
1113 AM ChST Fri Jun 28 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...

NEAR EQUATORIAL TROUGH...
A Near Equatorial Trough (NET) originates near the southern
Philippines, entering the area of responsibility near 5N130E and
extends southeast, to then exit the AOR near EQ137E, staying well
south of the main islands of Palau and Yap Proper. Pockets of
moderate convection occurring within the NET and along its northern
periphery where trade convergence is enhanced, across the main
islands of Palau but south of Yap Proper. The NET will linger and
drift northward over the coming days, possibly transitioning to a
weak monsoon-like trough, with convection increasing for Palau and
Yap.

TRADE-WIND TROUGHS...
A pair of westward-moving trade-wind troughs are helping to focus
showers and thunderstorms. One southwest of Chuuk extending
northwest towards Yap Proper, and another between Chuuk and Pohnpei.
While these troughs and attendant convection will continue west,
satellite-derived precipitable water products show a band of
increased moisture between 2N and 10N that will help convection to
gradually redevelop over the weekend as the ITCZ becomes more
established.

TUTT...
A Tropical Upper-Tropospheric Trough (TUTT) stretches from 18N130E
eastward to a TUTT low north of the Marianas, then northeast and
exiting the AOR near 25N148E. Showers and thunderstorms are beneath
the TUTT cell north and west of the Marianas and southeast of Iwo To.
The TUTT cell will continue to drift slowly west southwest over the
coming days and weaken slightly, with attendant convection gradually
diminishing.

OTHER SYSTEMS...

...ITCZ/TRADE CONVERGENCE...
A region of trade convergence is transitioning to an Inter-
Tropical Convergence Zone (ITCZ). The convergence zone starts
near the NET to the east of Palau and south of Yap Proper
eastwards across Chuuk, Pohnpei and Kosrae, then south of Majuro
to east of the Date Line. Pockets of moderate to deep convection
occurring with the convergence zone, especially in the proximity
of passing trade troughs. The ITCZ is expected to become better
developed through the weekend, with convection increasing across
central and eastern Micronesia.

...SHEAR LINE...
A weak shear line enters the AOR near 25N163E and extends
southwest, ending near 20N147E. A line of low-topped showers are
occurring along the shear line, with some better vertical development
south of Minami Torishima in the vicinity of the TUTT. The shear
line will linger for about 24 hours and then slowly wash out with
showers diminishing.

$$

Slagle