Post-Tropical Cyclone Krosa (12W) – Tropical Cyclone Advisory #24 (FINAL): 0300 UTC 4 August 2025

…Krosa becomes extratropical over the far northern Pacific… …This is the last advisory…

Current storm information:

• Position: 42.7°N 163.0°E

• Movement: ENE at 22 knots (45 km/h)

• Intensity: 40 knots (75 km/h)

• Central pressure: 990 hPa

Trend:

• The post-tropical cyclone is forecast to gradually weaken during the next couple of days.

Discussion:

Krosa is very rapidly losing its remaining tropical characteristics. The mid-level circulation has completely decoupled from the surface circulation and the nearest convection is racing away to the east of the low-level center. The low-level circulation itself has also become sharply elongated, and well defined cold and warm fronts are connected to it. Cyclone phase diagrams currently classify it as a cold-core system, so Krosa is now a post-tropical cyclone. The intensity is lowered to 40 kts based on recent HYSAT scatterometer data.

The post-tropical cyclone should continue racing east-northeastward for the next couple of days before being absorbed by a large extratropical low over the southeastern Bering Sea on Wednesday.

This is the last advisory on Krosa.

Forecast positions and maximum winds

• 00 hrs: 42.7°N 163.0°E – 40 kts Post-tropical/extratropical

• 12 hrs: 43.4°N 168.3°E – 35 kts Post-tropical/extratropical

• 24 hrs: 44.0°N 176.3°E – 35 kts Post-tropical/extratropical

• 48 hrs: 48.3°N 168.6°W – 30 kts Post-tropical/extratropical

• 72 hrs: Absorbed by larger extratropical low