Tropical Depression (Invest 90W) – Tropical Cyclone Advisory #1: 0000 UTC 17 September 2025

Tropical depression forms well to the west of Guam; forecast to strengthen significantly and move slowly during the next few days

Author

Will Weaver
September 16, 2025

…Tropical depression forms well to the west of Guam… …Forecast to strengthen significantly and move slowly during the next few days…

Himawari-9 visible satellite image (Weathernerds)

Current storm information:

  • Position: 13.3°N 136.6°E

  • Movement: WNW at 8 knots (15 km/h)

  • Intensity: 30 knots (45 km/h) 

  • Central pressure: 1008 hPa

Trend:

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

Watches and warnings:

  • There are no land-based watches or warnings in effect.

Hazards affecting land:

  • Interests in the Yaeyama Islands should monitor the progress of this system.

The next advisory will be posted after 1200 UTC 17 September 2025.

Forecast positions and maximum winds

  • 00 hrs: 13.3°N 136.6°E – 30 kts

  • 12 hrs: 14.5°N 135.6°E – 30 kts

  • 24 hrs: 15.6°N 134.7°E – 35 kts

  • 48 hrs: 16.7°N 132.9°E – 45 kts

  • 72 hrs: 17.9°N 132.2°E – 60 kts

  • 96 hrs: 19.1°N 129.8°E – 75 kts

  • 120 hrs: 20.0°N 126.3°E – 95 kts

JMA forecast map