Typhoon Krosa (12W) – Tropical Cyclone Advisory #10: 0000 UTC 28 July 2025

Krosa strengthens a bit more as it passes well to the east of the Ogasawara Islands.

Author

Will Weaver
July 27, 2025

…Krosa strengthens a bit more as it passes well to the east of the Ogasawara Islands…

Himawari-9 visible satellite image (Weathernerds)

Current storm information:

  • Position: 25.9°N 145.2°E

  • Movement: N at 15 knots (25 km/h)

  • Intensity: 80 knots (150 km/h) - Category 1 

  • Central pressure: 962 hPa

Trend:

  • Some additional strengthening is possible during the next 24 hours.

Watches and warnings:

  • There are no land-based watches or warnings in effect.

Hazards affecting land:

  • None.

Discussion:

Himawari-9 visible satellite image, showing Krosa at the upper center of the image, with its massive equatorward outflow channel extending well to the south and southwest (Weathernerds)

Krosa has finally moved out of the influence of the monsoon gyre, and the typhoon has responded quite remarkably. Convection has very quickly wrapped all the way around the center and a banding eye has developed. However, in the last few hours, a substantial amount of dry air has become entrained into Krosa’s circulation, to the point that the eyewall has eroded somewhat. Krosa’s outflow has improved quite a bit, so it remains to be seen whether the typhoon can mix out this dry air. Despite Krosa’s relatively high latitude, its inflow is dragging the monsoon trough along with it, which is probably what will trigger a major pattern change this week. The intensity is increased to 80 kts, which is slightly ahead of a blend of T4.0 to T4.5 Dvorak fixes, but is in line with a 2025 UTC RCM-3 SAR pass that found winds of 82 kts in the eastern semicircle.

F-18 SSMIS 91GHz microwave satellite image (RAMMB/CIRA)

Now that Krosa has freed itself from the monsoon gyre’s influence, it should have a somewhat more favorable environment ahead of it. The only negative factor is a very dry air mass to the north, which is already evident just looking at Krosa now. This dry air will likely offset the low shear and warm waters, and only some slight additional strengthening appears likely during the next day or so. By Tuesday, steering currents are expected to collapse as Krosa gets stuck between the monsoonal circulation to the west and a subtropical ridge to the east, which will likely cause Krosa to stall. There is not much in the way of oceanic heat content in this area, so Krosa will likely weaken significantly through midweek due to upwelling of colder subsurface waters. By Thursday, a trough approaching from the west should cause Krosa to resume a general northward motion, and it could strengthen again by the end of the forecast period as it moves out of its cold wake.

Forecast positions and maximum winds

  • 00 hrs: 25.9°N 145.2°E – 80 kts

  • 12 hrs: 27.4°N 144.0°E – 85 kts

  • 24 hrs: 28.1°N 142.9°E – 80 kts

  • 48 hrs: 28.3°N 143.0°E – 70 kts

  • 72 hrs: 28.5°N 144.9°E – 60 kts

  • 96 hrs: 31.2°N 146.2°E – 60 kts

  • 120 hrs: 34.4°N 146.7°E – 65 kts

JMA forecast map