Tropical Storm Wipha (09W) – Tropical Cyclone Advisory #11: 0000 UTC 21 July 2025

Center of Wipha emerging over the Gulf of Tonkin

Author

Will Weaver
July 20, 2025

…Center of Wipha emerging over the Gulf of Tonkin…

Himawari-9 visible satellite image (Weathernerds)

Current storm information:

  • Position: 21.5°N 109.4°E

  • Movement: W at 10 knots (20 km/h)

  • Intensity: 45 knots (85 km/h)

  • Central pressure: 985 hPa

Trend:

  • Some strengthening is forecast during the next 24 hours.

Watches and warnings:

  • All storm signals for Hong Kong and Macau have been dropped. There are no land-based watches or warnings in effect.

Hazards affecting land:

  • Wipha is likely to produce tropical storm conditions in northern Vietnam, including in the Hanoi metropolitan area, beginning on Tuesday. Heavy rainfall associated with Wipha and its remnants will spread over northern Laos and northern Thailand by Wednesday.

Discussion:

Himawari-9 visible satellite image (Weathernerds)

The center of Wipha has traversed the Leizhou Peninsula and is now in the process of emerging over the northeastern Gulf of Tonkin. Despite spending a fairly good amount of time over land, Wipha’s circulation remains well defined, with remnants of an eyewall present to the west of the center on radar imagery. However, the convective structure is quite ragged, with a fragmented central dense overcast over the center and an intense feeder band extending to the south. The intensity is lowered to 45 kts, based on surface observations and scatterometer data.

Composite radar image (CyclonicWx)

Wipha is firmly embedded in strong easterly flow, and it will be spending the next 24 hours or so over the Gulf of Tonkin. Wipha has a brief window of opportunity to regain some strength, but a sharp increase in shear is expected just before Wipha makes landfall near Hanoi on Tuesday, which should put an end to any strengthening. After landfall, Wipha should rapidly weaken over rough terrain before dissipating over northern Laos on Wednesday.

Forecast positions and maximum winds

  • 00 hrs: 21.5°N 109.4°E – 45 kts inland

  • 12 hrs: 21.1°N 108.0°E – 50 kts 

  • 24 hrs: 20.8°N 106.9°E – 60 kts

  • 48 hrs: 20.5°N 103.9°E – 30 kts inland

  • 72 hrs: Dissipated

JTWC forecast map