WPAC Tropical Weather Outlook: 6/26/25

Active tropical cyclones:

• There are no tropical cyclones.

Disturbances/invest areas:

• Invest 97W (northwest of Guam): An area of low pressure located west-northwest of Guam is producing a large area of disorganized showers and thunderstorms. This system is embedded in a complicated synoptic environment characterized by a weak TUTT cell to the northwest, a stronger TUTT cell northeast of the Marianas, a monsoon trough to the south, and another weak low pressure area to the east-southeast of Guam. This system is forecast to meander northwest of the Marianas during the next couple of days. If it does not become absorbed into the low east-southeast of Guam, it could become a tropical depression by early next week as it moves westward into the Philippine Sea. 

  Formation chance through 48 hours: MEDIUM - 40%

  Formation chance through 7 days: MEDIUM - 60%

• Disturbance A (east-southeast of Guam): Another area of low pressure is located east-southeast of Guam and is also producing a large area of disorganized showers. Upper-level winds are not particularly conducive for development due to the presence of a strong TUTT cell to the north, but as the system moves northward, they could become favorable for the formation of a subtropical or tropical depression early next week. This system is likely to remain east of the Marianas, but could cause scattered showers and thunderstorms over those islands during the next few days. 

  Formation chance through 48 hours: LOW - 10%

  Formation chance through 7 days: MEDIUM - 60%

• Disturbance B (west of Palawan): A low pressure area is forecast to form along the monsoon trough west of Palawan early next week. Although upper-level winds will likely only be marginally conducive for development, a tropical depression could form by Tuesday or Wednesday as the system moves northward into the South China Sea.

  Formation chance through 48 hours: VERY LOW - 0%

  Formation chance through 7 days: MEDIUM - 40%