Severe Tropical Storm Wipha (#09W) – Tropical Cyclone Advisory #12: 1200 UTC 21 July 2025

Wipha restrengthens slightly while continuing to traverse the Gulf of Tonkin

Author

Will Weaver
July 21, 2025

…Wipha restrengthens slightly while continuing to traverse the Gulf of Tonkin…

Himawari-9 infrared satellite image (Weathernerds)

Current storm information:

  • Position: 21.0°N 108.4°E

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

  • Intensity: 50 knots (95 km/h)

  • Central pressure: 984 hPa

Trend:

  • Some additional strengthening is forecast during the next 12 hours, followed by rapid weakening as Wipha moves inland over Vietnam.

Watches and warnings:

  • There are no land-based watches or warnings in effect. For local and marine watches and warnings, refer to products from your local weather office.

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 infrared satellite image (Weathernerds)

Wipha has gotten a bit better organized since the previous advisory now that its center is fully over water. The central dense overcast has become less ragged with very intense convection beginning to wrap back around the circulation center. Radar data backs this up, with an area of very intense convection south and west of the center. The center itself appears to have made a slight jump to the south of its previous track and location. Despite these improvements in Wipha’s structure, it is already beginning to exhibit signs of being impacted by increasing easterly shear, as the equatorward outflow channel is becoming restricted. The intensity is increased to 50 kts, based primarily on surface observations and also on CIMSS ADT and D-PRINT estimates of about 50 kts. 

Composite radar image (CyclonicWx)

There are no changes to the forecast. Wipha is forecast to make landfall in Vietnam near Halong in about 12 hours and pass just to the south of Hanoi. A little bit of additional strengthening is possible before then. After landfall, rugged terrain and strong shear should make quick work of Wipha’s circulation, and Wipha should dissipate over northern Laos on Wednesday or Thursday.

Forecast positions and maximum winds

  • 00 hrs: 21.0°N 108.4°E – 50 kts

  • 12 hrs: 20.6°N 107.2°E – 55 kts on the coast

  • 24 hrs: 20.6°N 105.9°E – 40 kts inland

  • 48 hrs: 20.7°N 103.2°E – 25 kts Post-tropical/remnant low inland

  • 72 hrs: Dissipated

JMA forecast map