Typhoon Krosa (12W) – Tropical Cyclone Advisory #8: 0000 UTC 27 July 2025

Krosa becomes a typhoon.

Author

Will Weaver
July 26, 2025

…Krosa becomes a typhoon…

Himawari-9 visible satellite image (Weathernerds)

Current storm information:

  • Position: 20.4°N 145.4°E

  • Movement: N at 10 knots (20 km/h)

  • Intensity: 75 knots (140 km/h) - Category 1 

  • Central pressure: 965 hPa

Trend:

  • Little change in strength is expected during the next 24 hours.

Watches and warnings:

  • Tropical storm warning (NWS): Agrihan, Pagan, Alamagan

Hazards affecting land:

  • None. (The islands under the tropical storm warning are uninhabited.)

Discussion:

Himawari-9 visible satellite loop (Weathernerds)

Krosa is starting to show some signs of decreasing shear affecting it. Although the shear remains moderate to strong (25 to 30 kts out of the northwest), the tropical cyclone continues to exhibit an intense central cold cover (CCC) pattern that has gradually built over the circulation center. Convective hot towers have also begun flaring around the center, suggesting that the inner core has continued to develop, and this inner core is evident on microwave satellite imagery as a mostly complete eyewall feature that has wrapped most of the way around the center. Although the outflow remains restricted in the northwestern quadrant due to the shear, it has improved in all other quadrants. Dvorak fixes range from T4.0 to T5.0. Given the improved structure, the JMA estimate appears to be closest to reality, and the intensity is increased to 75 kts, making Krosa a typhoon.

F-18 SSMIS 89 GHz microwave satellite image

The forecast remains generally unchanged except for Krosa’s higher starting intensity. Krosa is forecast to move northward during the next few days, with a gradual turn toward the northwest late Monday into Tuesday as the subtropical ridge reorients. Little change in strength appears likely through then - while the shear is forecast to relax by Monday, Krosa will encounter a substantially drier air mass east of the Ogasawara Islands, and this will likely result in some weakening. Krosa is expected to slow and stall on Tuesday and Wednesday as a large and sprawling monsoon trough becomes established in the subtropical Pacific, but it should resume moving generally northward shortly after. This monsoon trough should also moisten the environment, which could enable some restrengthening.

Forecast positions and maximum winds

  • 00 hrs: 20.4°N 145.4°E – 75 kts

  • 12 hrs: 23.0°N 145.8°E – 75 kts

  • 24 hrs: 25.7°N 145.7°E – 70 kts

  • 48 hrs: 28.3°N 144.0°E – 65 kts

  • 72 hrs: 28.6°N 143.9°E – 60 kts

  • 96 hrs: 29.0°N 145.2°E – 60 kts

  • 120 hrs: 31.6°N 146.8°E – 65 kts

JMA forecast map