WPAC Tropical Weather Outlook - 6/21/25

Active tropical cyclones:

• There are no tropical cyclones.

Disturbances/invest areas:

• Invest 95W (near the northernmost Mariana Islands): An area of low pressure located northeast of the northernmost Mariana Islands is producing disorganized showers and thunderstorms. Environmental conditions are conducive for development, and a tropical depression could form by Monday as the system moves north-northwestward toward Japan. By the middle of the week, the system will be moving over cooler SSTs, which will end its development chances.

  Formation chance through 48 hours: MEDIUM - 40%

  Formation chance through 7 days: MEDIUM - 60%

• Disturbance A (near Kwajalein Atoll): A weak area of low pressure and an associated surface trough located near Kwajalein Atoll is producing a large area of sheared showers and thunderstorms. This system is expected to move quickly west-northwestward over the eastern portion of the basin through the middle of next week with little or no development due to strong upper-level winds. By Wednesday, however, environmental conditions are expected to become more favorable for development as the system turns northward, and a tropical depression could form late next week.

  Formation chance through 48 hours: VERY LOW - 0%

  Formation chance through 7 days: MEDIUM - 40%

• Disturbance B (near Palawan): An area of low pressure - not the one currently marked on the map - is forecast to form along the monsoon trough late next week. Some limited development of this system is possible as it moves north-northwestward west of Luzon.

  Formation chance through 48 hours: VERY LOW - 0%

  Formation chance through 7 days: LOW - 10%