Tropical Storm Wipha (09W/Crising, formerly 96W) – Tropical Cyclone Advisory #6: 1200 UTC 18 July 2025

Center of Wipha passing over the Babuyan Islands, torrential rainfall occurring over southern Taiwan, the Batanes and Babuyan Islands, and northern Luzon

Author

Will Weaver
July 18, 2025

…Center of Wipha passing over the Babuyan Islands… …Torrential rainfall occurring over southern Taiwan, the Batanes and Babuyan Islands, and northern Luzon…

Himawari-9 infrared satellite image (Weathernerds)

Current storm information:

  • Position: 19.4°N 122.1°E

  • Movement: NW at 15 knots (25 km/h)

  • Intensity: 40 knots (75 km/h)

  • Central pressure: 986 hPa

Trend:

  • Some strengthening is forecast during the next 24 hours.

Watches and warnings:

  • TCWS #2 (Philippines): Batanes Islands, Babuyan Islands, all of northern Luzon north of a line extending from northern Ilocos Sur to the Isabela/Aurora border

  • TCWS #1 (Philippines): Parts of northern Luzon not under TCWS #2 and north of a line extending from central Pangasinan to central Aurora

  • The No. 1 standby signal is expected to be issued for Hong Kong and Macau later tonight.

PAGASA wind signal map (click to enlarge)

Hazards affecting land:

  • Wipha is likely to produce widespread heavy rainfall across much of the Philippines and southern Taiwan during the next couple of days as it interacts with an active monsoon trough. The heaviest rainfall will likely occur along coastal regions of northern Luzon, Mindoro, and Panay. Storm total rainfall of up to 500 mm is possible in isolated coastal areas through Sunday morning; storm total rainfall of 150 to 200 mm is possible through Saturday in interior areas, including the Metro Manila area. In addition, storm total rainfall of up to 300 mm is possible along the southern and eastern coasts of Taiwan. This rainfall is likely to cause widespread flooding and mudslides in vulnerable areas. For additional information, including possible warnings, refer to products from your local weather office.

  • Interests in southern China, including Hong Kong and Macau, as well as northern Vietnam should monitor the progress of this system.

Discussion:

Himawari-9 infrared satellite image (Weathernerds). Wipha looks like a hot mess of fragmented convective banding over the Philippines

Wipha is continuing to gradually consolidate as it enters the Luzon Strait, although it continues to have characteristics of a monsoon depression (in fact, JTWC is still calling it a monsoon depression and not a tropical storm). The system continues to consist of an enormous area of convection which is continuing to develop into discrete bands in all quadrants, but the center remains quite broad and convection near it is more scattered and fragmented. The center is so broad that it remains difficult to discern an exact center location on either satellite or radar imagery, but it appears to be over the Babuyan Islands. There have been no recent scatterometer passes, and surface observations are scarce, but Dvorak estimates range from T2.5 to T3.0, and so the intensity remains 40 kts.

Composite radar image (CyclonicWx)

Wipha remains embedded within a large monsoonal circulation, with a strong subtropical ridge to its northeast. As that monsoonal circulation becomes the primary steering mechanism, Wipha should gradually turn westward as it moves through the Luzon Strait. Since Wipha’s center will not be making any landfalls during the next day or two, its circulation will likely remain quite broad. Even though environmental conditions are expected to be quite favorable for strengthening at least through Sunday morning, Wipha is forecast to intensify only very gradually owing to that broad circulation, and the current forecast only peaks Wipha at 45 kts as it passes south of Hong Kong and Macau and makes landfall on the Leizhou Peninsula early Monday. A gradual turn toward the west-southwest is expected after this landfall as Wipha interacts with a new monsoonal circulation forecast to develop in the central South China Sea, and this motion could keep Wipha over the Gulf of Tonkin long enough for a quick burst of strengthening before it makes its final landfall in northern Vietnam on Tuesday. Rapid weakening is expected after this last landfall, and Wipha will probably be well on its way to degenerating into a broad area of low pressure over land by the end of the forecast period.

Forecast positions and maximum winds

  • 00 hrs: 19.4°N 122.1°E – 40 kts 

  • 12 hrs: 20.0°N 119.6°E – 40 kts 

  • 24 hrs: 21.1°N 117.8°E – 45 kts 

  • 48 hrs: 21.6°N 112.2°E – 45 kts

  • 72 hrs: 20.9°N 108.5°E – 55 kts

  • 96 hrs: 20.4°N 105.2°E – 40 kts inland

  • 120 hrs: 20.3°N 102.0°E – 25 kts inland

JMA forecast map (click to enlarge)