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AXPQ20 PGUM 012017

TWDPQ 



Tropical Weather Discussion

National Weather Service Tiyan GU

617 AM ChST Thu May 2 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 spans across far western Micronesia, 

extending from 4N130E to EQ139E, well south of the main islands of 

Palau and Yap. Yesterday's ASCAT analysis showed a very weak 

circulation embedded in the NET, however, a circulation center was

difficult to discern in satellite imagery overnight. Widespread

cloudiness, disorganized clusters of showers, and a few 

thunderstorms are found along the NET. Moderate, low-level 

convergence in the northern peripheries is also generating patchier 

showers across Palau and Yap.



TRADE-WIND TROUGHS...

Scatterometry data shows the axis of a weak surface trough pushing 

west of the Marianas. Low-level convergence trailing behind this is 

generating patchy showers, mainly across the CNMI. Another weak 

surface trough is generating an area of patchy showers east of the 

Marianas, near 154E. Scatterometry data also captures a pair of 

troughs upstream of the NET. Moderate to deep convection is found in

parts of eastern Yap State, but the bulk of activity extends south 

to the equator. In central and eastern Micronesia, surges in the 

trade flow interact with a surface trough southeast of Chuuk coastal 

waters and with a broader trough between Pohnpei and Kosrae. This 

continues to bring about enhanced convection, most notably south of 

Pohnpei and across Kosrae.



...ITCZ...

The trade-convergence has a more notable, cross-equatorial component

over the past 24 hours and is now considered an ITCZ feature. The 

leading edge can be seen near Kapingamarangi, meandering eastward to

an embedded trough near Kosrae and crossing the Date line near 2N. 

Throughout this feature, a condensed area of widespread cloudiness 

and invigorated convection are found south of Pohnpei, spanning 

across Kosrae to about 170E, where the surface trough, trade-surge, 

and upper-level speed divergence is further supporting shower 

development. Patchy showers are found elsewhere along this boundary, 

mainly southern Marshalls and across country lines into Kiribati, 

south of 5N.



...DISCUSSION...

A fairly busy pattern remains in store for most of Micronesia. The 

trade-wind troughs will continue to push west across the region. The

NET remains pinned in far western Micronesia through the weekend,

with transient troughs moving through the northern peripheries.

Keeping an eye on a possible disturbance forming within the NET 

early next week. This is a climatological pattern favored for the 

month of May, however, more model consensus is needed to aid in the 

certainty of this outcome. So far, models hint at a weak circulation

forming, with the GFS as the outlier, dragging this circulation 

northward across Palau. Farther east, the ITCZ is expected to become

more fragmented in the next day or two, losing out on the cross- 

equatorial flow as well.



$$



IC