Tropical Cyclone 12W (Yagi) / Invest 01C / Invest 93W – Pacific
Tuesday, September 3, 2024

Current Snapshot

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By PDC’s Senior Weather
Specialist Glenn James

The Pacific Disaster Center’s (PDC Global) Tuesday, September 3, 2024, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 12W (Yagi)…is located approximately 296 NM north-northwest of Manila, Philippines

 

Northeast Pacific Ocean: There are no Tropical Cyclones…nor any areas of disturbed weather under investigation by the National Hurricane Center (NHC)

Central Pacific Ocean: There are no Tropical Cyclones…nor any areas of disturbed weather under investigation by the Central Pacific Hurricane Center (CPHC)

Western Pacific, Indian Ocean, and adjacent Seas:

Tropical Cyclone 12W (Yagi)

According to the JTWC Warning number 10, sustained winds are 55 knots with gusts to near 70 knots

Animated enhanced infrared satellite imagery depicts a partially exposed low-level circulation system (llcc) depicted in a slot of dry air with strong convective banding wrapping into the vortex center. Water vapor imagery reveals moderate eastward and strong equatorward upper-level outflow encouraging intensification. A llcc is also apparent on an image with a strong convective band nearly fully encircling the center.

tropical storm 12W is forecast to track in an overall westward direction over the next 36 hours while driven by an elongated ridge to the north. After 36 hours, the system will begin to round the southwestern periphery of the ridge, steering TS 12W in a west-northwest direction.

While in the South China Sea for the next 72 hours, the environment will be favorable with low vertical wind shear (5-10 knots), strong upper-level divergence, and warm sea surface temperatures. However, what will push TS 12W over the edge to rapidly intensify is high ocean heat content which will fuel the system to quickly peak to 110 knots at 60 hours.

After 72 hours, the system will begin to enter a region of moderate shear (10-15 knots) and begin to interact with the topography of Hainan Island and Luichow Peninsula. After emerging over the Gulf of Tonkin, TS 12W will begin dissipating at 96 hours after making landfall on mainland Vietnam and reach full dissipation over land by 120 hours.

>>> There’s an area of disturbed weather being referred to as Invest 01C, which is located approximately 138 NM southwest of Midway Island

This system is classified as a subtropical depression, generally characterized as having both tropical and
mid-latitude cyclone features.

Animated enhanced infrared satellite imagery depicts a highly asymmetric convective structure, with convective banding wrapping into a broad center. A microwave image reveals fragmented bands displaced over the eastern semicircle, with a weak, broad low-level circulation.

An image reveals an elongated circulation, with a weak core and maximum winds displaced over 90 NM to the north. The system is located under a deep subtropical trough, with low to moderate (15 to 20 knots) vertical wind shear.

Maximum sustained surface winds are estimated at 28 to 33 knots.

The potential for the development of a significant tropical cyclone within the next 24 hours remains low.

>>> There’s an area of disturbed weather being referred to as Invest 93W, which is located approximately 321 NM east of Iwo To, Japan

Enhanced multi-spectral satellite imagery and a microwave pass depict deep convection on the eastern side of a well developed low level circulation center. A scatterometer pass reveals a highly asymmetric wind field with 25-30 knot winds in the northeastern quadrant of the llcc, but much lighter winds in the remainder of the circulation.

Environmental analysis reveals favorable conditions for intensification due to warm sea surface temperatures, low (10-15 knot) vertical wind shear, and good divergence aloft.

Deterministic models provide poor indication of a consolidation, indicating 93W as a weak circulation gradually tracking north but due to the very small size of the circulation. The global models are not likely handling the system well and more development than currently depicted is possible.

Maximum sustained surface winds are estimated at 18 to 23 knots.

The potential for the development of a significant tropical cyclone within the next 24 hours remains medium.