Current Snapshot

The Pacific Disaster Center’s (PDC Global) Monday, August 12, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 06W (Maria)…is located approximately 112 NM north-northwest of Misawa, Japan – Final Warning

Tropical Cyclone 07W (Son-tinh)…is located approximately 489 NM east of Yokosuka, Japan

Tropical Cyclone 08W (Ampil)…is located approximately 661 NM south of Yokosuka, Japan

Tropical Cyclone 09W…is located approximately 737 NM southeast of Yokosuka, Japan

Northeast Pacific Ocean: There are no Tropical Cyclones

Central North Pacific: There are no Tropical Cyclones

Western Pacific, Indian Ocean and adjacent Seas:

Tropical Cyclone 06W (Maria) – Final Warning

According to the JTWC Warning number 24, sustained winds are 25 knots with gusts to near 35 knots

Animated enhanced infrared (eir) satellite imagery, surface observations, animated radar data, scatterometer data and an earlier pass indicate that the low level circulation center (llcc) associated with TS 06W (Maria) has rapidly jumped the Japanese Alps and reformed over water off the western coast of Honshu. The eir shows that the vortex decoupled as it crossed the mountain range and is now devoid of significant convection. A pass revealed a weak llcc had already started to form confirming the presence of a weak circulation west of Honshu.

Analysis reveals an unfavorable environment overall, with borderline sea surface temperatures, significant dry air in the mid-levels and weak outflow aloft though shear does remain low.

Tropical storm 06W (Maria) is forecast to continue tracking northwestward for the next 24 hours along the west side of a ridge centered far to the east. The system will steadily weaken during this time frame and as it does so, increasingly come under the steering influence of the lower-level flow pattern.

A strong anticyclone is forecast to move into Manchuria by 24 hours, with strong northerly winds pushing out into the Sea of Japan. by this time, the remnant vortex of TS 06W will be confined to the low-levels and a rapid turn east-southeastward is expected by the end of the forecast period as ts 06w dissipates in the western approaches of the Tsugaru Strait.

Tropical Cyclone 07W (Son-tinh)

According to the JTWC Warning number 4, sustained winds are 35 knots with gusts to near 45 knots

Animated enhanced infrared (eir) satellite imagery depicts a fully exposed low level circulation center (llcc), with convective debris and a few isolated convective towers isolated to the southern periphery. Upper-level cirrus streaks can be seen moving rapidly across the center of the llcc, indicative of the strong upper-level easterly flow associated with an upper-level low positioned to the southeast of the system. A sar pass revealed a symmetric wind field, with winds up to 30 knots closing off the core of the system to the southwest, while winds up to 42 knots were evident in the northeastern half of the circulation.

Analysis reveals a marginally unfavorable environment, with warm sea surface temperatures and moderate outflow being offset by strong easterly wind shear and extremely dry air aloft.

TS 07W has managed to maintain 40 knot intensity, even in the face of an otherwise unfavorable environment. Likely this won’t last much longer as the system will start to spin down imminently.

TS 07W is forecast to track northwestward through 36 hours along the southwestern side of the ridge to the northeast. By the end of the forecast, the steering ridge quickly shifts southward, allowing TS 07W to round the ridge axis and turn northeastward as it dissipates. The combination of increased shear, decreasing sea surface temperatures and
persistent dry air aloft, will lead to full dissipation between 36 and 48 hours to the east of Hokkaido.

Tropical Cyclone 08W (Ampil)

According to the JTWC Warning number 3, sustained winds are 40 knots with gusts to near 50 knots

Animated enhanced infrared (eir) satellite imagery depicts flaring convection around a still somewhat disorganized low level circulation center (llcc). The convection at present is starting to organize into a band on the western side of the circulation and flaring in pockets on the eastern side, but as of yet not wrapping into a defined center. A partial pass showed cyclonically curved wind barbs on the far western periphery of the circulation, with winds up to 25 knots. An earlier scatterometer pass showed winds up to 20 knots in a band to the north, and up to 30 knots in strong gradient flow along the southeastern flank of the circulation. Another image showed a small and defined llcc with deep convection primarily limited to the southern periphery.

Analysis reveals a favorable environment, characterized by very warm sea water temperatures, low (5-15 knot) vertical wind shear and good poleward outflow into a tutt-cell positioned to the northwest and moderate equatorward outflow provided by a weak anticyclone just east of the system.

Tropical depression 08W has steadily become better organized over the last day, but remains highly asymmetric in terms of the low-level wind field, and likely at least two low-level vortices lurking under the convection and convective blowoff. Over the next 24 to 36 hours, the extension of the ridge currently laying across the Marianas is expected to cut off into a deep-layer anticyclone near 20N 145E. As the gradient tightens in response to the building of the ridge, TD 08W will track northeastward until 36 hours. At this point, TD 08W will move into a somewhat weaker steering pattern, slowing down as it does so.

By 36 hours a significant pattern shift begins to emerge, with the strong ridge positioned at an anomalously high latitude of 40N, starts to move southward while building. This ridge quickly becomes the dominant steering influence for TD 08W, which will turn northward and accelerate after 36 hours along the western periphery of this ridge. TD 08W is expected to reach the ridge axis just south of Tokyo, and shortly after 96 hours will begin to turn northeastward as it rounds the ridge axis.

In terms of intensity, TD 08W currently sits in a favorable environment, tapping into enhanced outflow into a tutt-cell positioned to the northwest. Over the next 12-24 hours this outflow channel is expected to weaken and disappear, as the tutt-cell moves west and TD 08W moves northeastward. However, shear is expected to remain low and this should allow for the system to symmetrize, setting the stage for future intensification.

By 24 hours, an upper-level anticyclone is expected to develop over top of the system, which fuels a slightly faster rate of intensification up to 50 knots by 36 hours. At this point, another tutt-cell is forecast to develop to the north of the system, greatly enhancing upper-level outflow. By 72 hours, a larger upper-level anticyclone develops east of the system, greatly enhancing the already strong outflow, kicking off a period of rapid intensification as it approaches Japan. Peak intensity around 100 knots is expected as the system reaches the ridge axis near 96 hours, with relatively rapid weakening thereafter as the system moves over cooler waters and moderately elevated shear.

Tropical Cyclone 09W

According to the JTWC Warning number 1, sustained winds are 25 knots with gusts to near 35 knots