Tropical Depression (97W) – Tropical Cyclone Advisory #2: 0000 UTC 6 September 2025

Tropical depression moving westward across the South China Sea.

Author

Will Weaver
September 05, 2025

…Tropical depression moving westward across the South China Sea…

Himawari-9 visible satellite image (Weathernerds)

Current storm information:

  • Position: 17.6°N 116.4°E

  • Movement: W at 11 knots (20 km/h)

  • Intensity: 30 knots (55 km/h)

  • Central pressure: 1004 hPa

Trend:

  • Some gradual strengthening is forecast during the next 24 hours and the depression could become a tropical storm on Sunday.

Watches and warnings:

  • No. 1 Standby Signal (HKO/SMG): Hong Kong and Macau

Hazards affecting land:

  • Interests in southern China, including Hong Kong and Macau, should monitor the progress of the depression. It could produce periods of heavy rainfall in the region beginning early on Monday and continuing through midweek.

Discussion:

GCOM-W1 AMSR2 91GHz microwave satellite image

The tropical depression has gotten somewhat better organized as it moves westward away from Luzon. Some additional clusters of convection have developed close to its circulation center, and microwave satellite imagery suggests that this convection has begun to obscure the center. This convection remains somewhat fragmented with rudimentary banding features, with the exception of an equatorward outflow band feeding into the monsoon trough. Visible satellite imagery suggests that some dry air is filtering down from the Taiwan Strait, which is probably hampering the depression’s efforts to organize. Dvorak estimates continue to hover in the T1.5 to T2.0 range, so the intensity remains 30 kts.

The forecast track has shifted significantly to the west of the previous one, as I had suggested would probably happen given that most model tracks were well to the west at the time. The GFS, ECMWF, HAFS, and Google DeepMind model guidance continue to suggest that the mid-level ridge positioned to the north of Taiwan will continue to build westward during the next couple of days, and as a result TD 97W should turn toward the west-northwest later today. The environment is expected to be favorable with low to moderate shear and warm SSTs, so steady strengthening appears likely through Monday, when 97W is forecast to make landfall in southern China east of the Leizhou Peninsula. Rapid weakening is forecast after landfall, and 97W will likely dissipate inland on Tuesday.

Forecast positions and maximum winds

  • 00 hrs: 17.6°N 116.4°E – 30 kts

  • 12 hrs: 18.6°N 116.2°E – 35 kts

  • 24 hrs: 19.3°N 115.0°E – 40 kts

  • 48 hrs: 21.3°N 112.5°E – 50 kts

  • 72 hrs: 23.3°N 109.1°E – 30 kts inland

  • 96 hrs: Dissipated

JMA forecast map