Super Typhoon Ragasa (24W/Nando) – Tropical Cyclone Advisory #9: 1500 UTC 21 September 2025

Ragasa becomes a potentially catastrophic Category 5 super typhoon. Conditions expected to deteriorate in the Batanes and Babuyan Islands and along coastal northern mainland Luzon during the next few hours.

Author

Will Weaver
September 21, 2025

…Ragasa becomes a potentially catastrophic Category 5 super typhoon… …Conditions expected to deteriorate in the Batanes and Babuyan Islands and along coastal northern mainland Luzon during the next few hours…

…This is a particularly dangerous situation…

Himawari-9 infrared satellite image (Weathernerds)

Current storm information:

  • Position: 18.9°N 125.4°E

  • Movement: WNW at 9 knots (15 km/h)

  • Intensity: 145 knots (270 km/h) [Category 5] 

  • Central pressure: 902 hPa*

Trend:

  • Fluctuations in intensity are possible during the next 24 hours. However, Ragasa is expected to remain a super typhoon during that time.

Watches and warnings:

PAGASA wind signal map (click to enlarge)

  • Typhoon warning (Taiwan): Pingtung County, Taitung County

  • TCWS #3 (Philippines): Batanes Islands, Babuyan Islands, northern Ilocos Norte, northern Apayao, northern Cagayan

  • TCWS #2 (Philippines): Southern Ilocos Norte, southern Apayao, southern Cagayan, northern Ilocos Sur, Abra, Kalinga, central and eastern Mountain Province, eastern Ifugao, northern and central Isabela

  • TCWS #1 (Philippines): Southern Ilocos Sur, western Mountain Province, western Ifugao, southern Isabela, La Union, Benguet, Nueva Vizcaya, Quirino, Pangasinan, Nueva Ecija, Aurora, Zambales, Tarlac, Pampanga, Bulacan, northern Quezon, Polillo Islands

Hazards affecting land:

  • Typhoon conditions - destructive winds and heavy rainfall that could cause life-threatening flooding - are expected on the Batanes and Babuyan Islands on Monday. In addition, tropical storm conditions are possible along the southern coast of Taiwan and along the northern coast of mainland Luzon. Preparations to protect life and property should be completed as soon as possible.

  • Tropical storm conditions and extremely heavy rainfall are expected in portions of southern Taiwan, mainly near the central mountain range. Rainfall amounts of up to 500 mm are possible through Tuesday evening, and this rain could cause life-threatening flash flooding and landslides.

  • Monsoonal rainfall enhanced by Ragasa’s outflow could produce areas of heavy rainfall over portions of Luzon beginning during the next few hours and continuing through Tuesday. Storm total rainfall of up to 200 mm is possible through Tuesday evening.

  • Interests in southern China, including Hong Kong and Macau, should also closely monitor the progress of this system. It is possible that Ragasa will still be a very intense typhoon by the time it approaches that area on Wednesday.

Discussion:

WSFM MWI 89GHz microwave satellite image

Ragasa is an exceptionally impressive typhoon tonight, although it is beginning to show some signs that it has peaked in intensity. Ragasa continues to have an impressive and symmetric central dense overcast surrounding a small, clear, and very warm eye. However, cloud tops within the CDO have begun to warm during the past few hours, and the eyewall is beginning to become separated from the rest of the CDO. Microwave satellite imagery continues to suggest the presence of concentric eyewalls, so it is likely that Ragasa is beginning an eyewall replacement cycle. A Sentinel-1 SAR pass from 0934 UTC indicated winds of 144 kts in the northeastern quadrant. Dvorak estimates are a consensus T7.0 from the agencies with CIMSS ADT, D-PRINT, and SATCON estimates ranging from 137 to 147 kts; the intensity is increased to 145 kts, making Ragasa a Category 5 super typhoon.

The forecast is unchanged from the previous one. Ragasa is expected to move west-northwestward into the Luzon Strait on Monday morning and pass over the northern Babuyan Islands. Although the environment remains quite favorable for additional strengthening, Ragasa’s intensity will likely be governed by inner core dynamics and potential eyewall replacement cycles during the next couple of days. By Monday evening, Ragasa could experience some interaction with coastal northern Luzon that could begin a gradual weakening trend - this trend should become more profound by Wednesday as it passes south of Hong Kong and Macau and encounters stronger shear and northeasterly surface flow off the Taiwan Strait. Ragasa is expected to make landfall in the Leizhou Peninsula early on Thursday still as an intense typhoon before crossing the Gulf of Tonkin and moving over northern Vietnam late Friday evening.

Forecast positions and maximum winds

  • 00 hrs: 18.8°N 125.4°E – 145 kts

  • 12 hrs: 19.4°N 123.0°E – 145 kts

  • 24 hrs: 19.5°N 120.5°E – 140 kts

  • 48 hrs: 20.4°N 115.9°E – 130 kts

  • 72 hrs: 20.8°N 111.6°E – 105 kts

  • 96 hrs: 20.6°N 106.5°E – 55 kts

  • 120 hrs: 19.4°N 100.1°E – 25 kts Post-tropical/remnant low inland

JTWC forecast map

*Note: Corrected central pressure from 911 to 902 hPa based on a buoy observation of 900.3 hPa at around 0800 UTC with winds of 19 kts, suggesting the pressure was about 899 hPa at that point