Current Snapshot

The Pacific Disaster Center’s (PDC Global) Wednesday, September 18, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 15W (Pulasan), is located approximately 323 NM southwest of Sasebo, Japan

Tropical Cyclone 16W (Soulik), is located approximately 79 NM north of Da Nang, Vietnam

Northeast Pacific Ocean: There are no Tropical Cyclones.

Central Pacific Ocean: There are no Tropical Cyclones.

Western Pacific, Indian Ocean, and adjacent Seas:

Tropical Cyclone 15W (Pulasan)  

According to the JTWC Warning number 10, sustained winds are 40 knots…with gusts to near 50 knots

Animated enhanced infrared satellite imagery depicts a broadly circulating monsoon depression with subsident dry air descending over the center, fully exposing the low-level circulation center (llcc). The system is positioned farther north than expected in the last warning. As a result, Okinawa is in a more favorable position away from the maximum wind band spanning 120 NM to 255 NM from center. The system continues to maintain the characteristics of a monsoon depression with dry subsident air in the center, a band of convection wrapping from the eastern periphery, and broad wind radii.

Tropical storm 15W will continue to track northwestward while driven by the ridge to the north. The strong southwesterly flow supporting the dry central circulation will continue to support the structure of the monsoon depression throughout the forecast period. After passing south of Okinawa, the system will make landfall quickly following tau 24.

A secondary enhanced southerly flow on the eastern periphery of the broad circulation is expected to impact Okinawa within the first 12 hours of the forecast. The intensity of the monsoon depression will weaken gradually as the system moves away from the deep-layer ridge, decreasing the surface pressure gradient. Subsident continental dry air fed from the west will continue to erode the intensity until the system makes landfall after 24 hours and rapidly declines.

Tropical Cyclone 16W (Soulik)

According to the JTWC Warning number 4, sustained winds are 30 knots…with gusts to near 40 knots

What was previously identified as two vorticity maxima in the South China Sea have continued consolidating into one system over the last six hours as depicted in a cimss 850mb vorticity analysis, placing the primary vorticity maxima in the vicinity of the best track position with a lobe extending southwestward.

Animated enhanced infrared satellite imagery depicts strong southwesterly support to an elongated region of turning southeast of Hainan Island. Convection has built in the region spanning from the southwest to the northeast, and strong poleward outflow is apparent into diffluent easterly upper-level flow.

Tropical depression 16W will trackwestward throughout the forecast period while steered by a ridge to the north. The system will make landfall between 24-36 hours where elevated topography in Vietnam will initiate weakening.

The system will remain in moderately favorable conditions for intensification for the first 24 hours of the forecast. The primary mitigating factor for intensification will be vertical wind shear that will increase to 15-20 knots between 12-24 hours. Between 24-36 hours, the system will make landfall and dissipate by 48 hours.