Tropical Storm Kajiki (19W/Isang) – Tropical Cyclone Advisory #3: 0000 UTC 23 August 2025

Tropical Storm Kajiki forms in the central South China Sea, expected to rapidly intensify today.

Author

Will Weaver
August 22, 2025

…Tropical Storm Kajiki forms in the central South China Sea… …Expected to rapidly intensify today…

Himawari-9 visible satellite image (Weathernerds)

Current storm information:

  • Position: 17.5°N 116.6°E

  • Movement: W at 15 knots (25 km/h)

  • Intensity: 40 knots (75 km/h)

  • Central pressure: 998 hPa

Trend:

  • Steady to rapid strengthening is expected during the next 24 hours, and Kajiki will likely become a typhoon on Sunday.

Watches and warnings:

PAGASA wind signal map (click to enlarge)

  • TCWS #1 (Philippines): Western Babuyan Islands, Ilocos Norte, Apayao, western Cagayan, Ilocos Sur, Abra, Kalinga, western Isabela, Mountain Province, Ifugao, La Union, Benguet, western Nueva Vizcaya, and northwestern Pangasinan. These signals will likely be dropped later today.

Hazards affecting land:

  • Interests in Hainan Island and central Vietnam should monitor the progress of 19W. The system could bring typhoon conditions to those areas on Sunday and Monday. Preparations to protect life and property should be rushed to completion.

Discussion:

WSFM MWI 89GHz microwave satellite image

The depression has been responding very quickly to a much more favorable environment in the South China Sea, and it has become much better organized during the last 12 hours. Although CIMSS shear analysis indicates about 20 to 25 kts of easterly shear, the system’s fast forward speed is blunting this shear’s impact. Very intense clusters of convection have quickly flared near the circulation center and consolidated into a well-defined central dense overcast with impressive radial outflow. So far, this has not yet translated into the development of an inner core, but microwave satellite imagery indicates that the banding is wrapping tightly into the center. Dvorak estimates are a consensus T3.0, with CIMSS ADT, D-PRINT, and SATCON estimates all at tropical storm strength, so the system is now Tropical Storm Kajiki, and the intensity of 40 kts is a blend of these estimates although it may be conservative.

The forecast is generally the same as the previous one, although it has been nudged slightly to the north. Kajiki is more or less riding the southwestern edge of the subtropical ridge as it builds westward, and as a result it should move ever so slightly north of due west during the next couple of days. Given how quickly Kajiki is organizing as the environment becomes more favorable, rapid intensification does appear to be on the menu (both CIMSS AI-RI and RAMMB RIPA guidance have high probabilities), and it appears likely that Kajiki will become a typhoon as early as tonight. By Sunday night, Kajiki should pass very near or over the southern coast of Hainan Island, which will likely slow its rate of intensification. However, Kajiki will likely still be a strong typhoon by the time it makes its final landfall in north central Vietnam on Monday. The intensities listed below are higher than the JTWC and JMA forecasts indicate.

Forecast positions and maximum winds

  • 00 hrs: 17.5°N 116.6°E – 40 kts

  • 12 hrs: 17.9°N 113.8°E – 55 kts

  • 24 hrs: 18.2°N 111.2°E – 70 kts

  • 48 hrs: 18.6°N 107.3°E – 85 kts

  • 72 hrs: 19.2°N 103.1°E – 25 kts inland

  • 96 hrs: 19.5°N 99.8°E – 20 kts Post-tropical/remnant low inland

  • 120 hrs: Dissipated

JTWC forecast map

One last thing…

Do you like what you see? Please consider sending a tip via Ko-fi! I wear a lot of hats between a day job, being a photographer, and being a worldwide weather enthusiast, and while I will never put any of my content behind a paywall (paywalls kind of defeat the purpose of this blog/newsletter/thingy), your tips definitely help! You can send a tip via the following link: https://ko-fi.com/willweaverrva