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AXPQ20 PGUM 062141

TWDPQ 



Tropical Weather Discussion

National Weather Service Tiyan GU

741 AM ChST Tue May 7 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...

The Near-Equatorial Troughs (NET) enters the area of 

responsibility (AOR) near 5N130E, then extending east through 

Joint Typhoon Warning Center (JTWC) Invest 91W sub-low south of 

the main islands of Palau near 4N136E, then through Invest 90W 

sub-low southeast of Yap Proper near 5N143E, then southeast 

through another circulation south of Weno, Chuuk near 2N150E, and 

exiting the AOR near EQ154E. Moderate to deep convection is 

occurring within and north the NET, especially from southeast of

Yap and Palau to the circulation south of Chuuk.



TRADE-WIND TROUGHS/SURGES...

A surge in trade trough/surge is pushing across Kosrae and

Pohnpei into eastern Chuuk state. Another trough/surge is 

pushing across the Marshall Islands. Pockets of moderate to deep 

convection occurring, especially from north of Weno, Chuuk south 

and east across Pohnpei and Kosrae to south of Kwajalein.



SURFACE TROUGH/LOW...

A surface trough extends north from 10N151E north of Weno, Chuuk,

staying east of the Marianas, and terminating at a well-defined

surface low near 25N150E, west of Minami Torishima. Spotty showers

occurring with the trough, but a pocket of moderate to deep

convection is north of Weno, Chuuk. Showers are low-topped near 

the surface low, but to the south and east, moderate to deep

convection occurring under the upper-level low, well to the north

and west of Wake Island.



TUTT...

The Tropical Upper Tropospheric Trough (TUTT) enters the AOR near

25N158E and extends southwest through a TUTT cell centered south

of Minami Torishima near 22N154E and ending southwest of Guam near

11N143E. Moderate to deep convection near the TUTT cell south and

east of Minami Torishima, with spotty showers extending southwest.



SHEAR LINE...

A shear line enters the AOR near the surface low at 25N150E,

extending south and then west across Agrihan and then dissipating

near 21N138E, southwest of Iwo To. Spotty showers occurring along

and north of the shear line.



...ITCZ...

The Inter Tropical Convergence Zone (ITCZ) near the circulation

south of Weno, Chuuk near 4N150E extends east, staying south of 

Pohnpei, passing over Kosrae and the southern Marshall Islands, 

and exiting the AOR near 5N180. Pockets of moderate to deep 

convection occurring along the ITCZ, especially where convergence

is being enhanced with the aforementioned trade troughs/surges.



...DISCUSSION...

The NET with the embedded circulations will persist and may slowly

meander north. Some model guidance is indicating one of the 

circulations developing into a significant Tropical Cyclone (TC) 

as it moves through the NET south of Guam, towards Yap and Palau.



The trade troughs/surges will continue to push west across 

central and eastern Micronesia, enhancing convection where the 

troughs/surges merges with the ITCZ and trade convergence zone. 



The surface trough and low will continue to drift north and west,

merging with and approaching cold front around Thursday. The shear

line extending from the low will dissipate over the next couple 

of days.



The TUTT will slowly drift to the east over the coming days, with

convection under the TUTT cell dissipating as the it opens up and

approaches Wake Island.



The ITCZ will linger through the week, with pockets of moderate to

deep convection continuing. The ITCZ may transiting to a zone of 

trade convergence and drift slightly north this weekend.



$$



Slagle