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AXPQ20 PGUM 232009

TWDPQ 



Tropical Weather Discussion

National Weather Service Tiyan GU

609 AM ChST Wed Apr 24 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...

A series of broad trade-wind troughs extend across the region. The 

first trough is located just west of Palau from 10N133 to 3N135.

Scattered showers and isolated thunderstorms extend from Palau, and

into western Yap State, passing just south of Yap Proper's coastal

waters.



The second trough is located east of the first trough, and extends

southward from near Guam at 13N143E to 3N146E. This trough is helping

to extend the scattered showers and isolated thunderstorms in eastern

Yap State to the rest of Yap State and into Chuuk State, where the

convection merges with the ITCZ and embedded troughs discussed 

below. Scattered showers also extend northward into Guam and Rota, 

ending just south of Tinian in the Marianas. So far isolated 

thunderstorms near the Marianas have are mainly south of Guam, about 

40 nautical miles or greater from the island, according to reports 

from the Global Lightning Detection (GLD) network. Rain has been

heavy across Guam, dropping up to 2 inches in the last 3 hours in

central Guam as of 20Z.



...ITCZ...

Scatterometer data yesterday showed a developing Inter-tropical

Convergence Zone (ITCZ) from near Weno in Chuuk State, and extends

eastward across Pohnpei, Kosrae, Majuro and beyond the Dateline. The

latest Scatterometer data has decreased the overall southeasterly 

flow, which helps to define the ITCZ, but regardless widespread 

convergence is producing scattered to numerous showers and isolated 

thunderstorms across Chuuk, Pohnpei, Kosrae, and Majuro. Currently 

the heaviest convection looks to be near Pohnpei where and passing 

trough is helping to enhance convection near the island. Showers are 

still struggling to reach up to Wotje and other northern islands of 

the RMI, which are still in extreme to exceptional drought.



...DISCUSSION...

The troughs west of Palau and then between Yap and Chuuk will

continue to drift westward, keeping the potential for scattered

showers at Palau and Yap over the next couple of day, while the

Marianas is expected to return to a dry trade-wind pattern after the

nearby trough moves off to the west tonight.



The ITCZ is expected to persist through at least Friday, with passing

trough helping to locally intensify convection within the ITCZ. The

heaviest showers are expected to mostly be between 3 and 7N, but the

troughs within the ITCZ may help to lift showers further north at

times.



$$



Schank