Tropical Storm Fengshen (30W) – Tropical Cyclone Advisory #10: 0000 UTC 21 October 2025

Fengshen slowing down southeast of Hainan Island...

Author

Will Weaver
October 20, 2025

…Fengshen slowing down southeast of Hainan Island…

Himawari-8 visible satellite image (Weathernerds)

Current storm information:

  • Position: 18.2°N 112.1°E

  • Movement: Nearly stationary

  • Intensity: 45 knots (85 km/h)

  • Central pressure: 996 hPa

Trend:

  • Little change in strength is forecast during the next 24 hours.

Watches and warnings:

  • No. 3 Strong Wind Signal (HKO/SMG): Hong Kong, Macau

Hazards affecting land:

  • The outermost rainbands of Fengshen are currently producing heavy rainfall and gusty near-gale winds along the southern coast of China, including Hainan Island, Hong Kong, and Macau, as well as in far southwestern Taiwan. These conditions will likely continue for another day or so.

Discussion:

WSFM MWI 89GHz microwave satellite image

It appears that Fengshen may be approaching its peak intensity. The tropical storm’s convective structure has improved quite a bit since the previous advisory, with the clusters of convection finally consolidating into a ragged central dense overcast. Microwave satellite imagery shows bands of convection wrapping into the circulation center from the north and east. Despite this apparent increase in organization, though, Oceansat scatterometer data and visible satellite imagery indicate that the circulation remains quite elongated. In addition, the wind field is starting to merge with the strong northeasterly cold surge coming off the Taiwan Strait, with a large swath of 30 to 35 kt winds extending up the strait. The intensity remains 45 kts, based on Dvorak fixes of T3.0 from PGTW and RJTD, T3.5 from KNES, and somewhat lower CIMSS ADT and D-PRINT estimates.

The forecast is generally unchanged. Fengshen is becoming embedded within the cold surge, which is causing its forward speed to slow. The cyclone should turn sharply to the southwest later today as it begins to be nudged by the northeasterly surge flow. Although SSTs are quite warm and shear is relatively low, the cool, stable air associated with the surge is expected to quickly erode Fengshen’s convection during the next day or two. Fengshen will likely become post-tropical as it reaches the coast of Vietnam, as the system is expected to be almost completely convection-free by that point. The circulation should dissipate within the surge flow shortly after moving inland.

Forecast positions and maximum winds

  • 000 hrs: 18.2°N 112.1°E – 45 kts 

  • 012 hrs: 16.9°N 111.1°E – 45 kts

  • 024 hrs: 16.2°N 110.2°E – 35 kts

  • 048 hrs: 15.4°N 108.4°E – 30 kts Post-tropical/remnant low inland

  • 072 hrs: 14.2°N 107.6°E – 20 kts Post-tropical/remnant low inland

  • 096 hrs: Dissipated

JMA forecast map