Tropical Storm Chanthu (04W) Expected to Strengthen18.1N 114.1E
Tropical Storm Chanthu (04W), located approximately 370 nm south-southeast of Hong Kong, has tracked northward at 6 knots over the past six hours. Maximum significant wave height is 15 feet.
The system shows improved convective banding wrapping around a partially exposed low level circulation center (LLCC) from the south and east. Environmental analysis shows TS Chanthu is located just south of an upper level low supporting good outflow aloft and is in an area of low vertical wind shear (VWS).
TS 04W has recently turned northward due to a weakness in the subtropical steering ridge that has developed in response to a passing mid-latitude upper level trough to the north.
As the steering ridge rebuilds, the system should begin to track more northwestward along the southern periphery of a narrow ridge indicated in upper level observations from China.
TS 04W will continue to intensify throughout the forecast period due to good outflow, warm sea surface temperatures, and low VWS. It is forecast to make landfall after TAU 48 and begin to dissipate over land.