Current Snapshot

The Pacific Disaster Center’s (PDC Global) Saturday, March 29, 2025, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas

Current Tropical Cyclones:

Tropical Cyclone 27S (Courtney)…is located approximately 727 NM southwest of Cocos Islands

Northeast Pacific Ocean: There are no Tropical Cyclones

The last regularly scheduled Tropical Cyclone Activity Report of the 2024 eastern North Pacific Hurricane Season has been issued. Routine issuance of this section of the PDC product will resume on May 15, 2025. During the off-season, Special Tropical Weather Outlooks will be issued as conditions warrant by the NHC.

Central Pacific Ocean: There are no Tropical Cyclones

The 2024 central North Pacific hurricane season has ended. As such, the final routine Tropical Cyclone Activity Report for the 2024 season has been issued. Routine issuance of this section of the PDC product will resume on June 1, 2025. During the off-season, Special Tropical Weather Outlooks will be issued as conditions warrant by the CPHC.

Western Pacific, Indian Ocean, and adjacent Seas: 

South Indian Ocean

Tropical Cyclone 27S (Courtney)

According to the JTWC warning number 16, sustained winds were 100 knots with gusts to near 125 knots

Animated multi-spectral satellite imagery and enhanced infrared (eir) imagery depict a compact, symmetrical cdo with a 10nm wide, very warm eye. A microwave image reveals a complete eyewall though the eastern side is significantly weaker and thinner than the eyewall on the western side.

As well, the microwave image reveals a stationary banding feature (sbc) wrapping in from the north along the eastern side and connecting with the eyewall in the southwestern quadrant. The presence of the sbc is a sign of an eyewall replacement cycle (erc) kicking off within the next 12 to 24 hours.

The environment remains favorable with low vws, moderately warm ssts and good outflow aloft.

Tropical cyclone 27S (Courtney) will continue to track along the northwestern side of the str to the southeast and trace a graceful left turn, such that by 48 hours it will be tracking due south as it reaches the ridge axis. In the near-term, while the environment remains overall favorable, the primary driver of intensity through 24 hours will be the potential erc.

The cimss m-perc is currently predicting a 50 percent chance of an erc, and based on the sbc seen in the microwave imagery, it is likely that erc will in fact begin within the next 12 hours or
so. Intensity will drop rather quickly once erc begins and due to an expected sharp increase in shear beginning after 24 hours, it is unlikely that the erc will be able to complete the cycle and the system will not recover.

Shear is forecast to exceed 35 knots by 36 hours and only increase thereafter. Extremely dry air begins to intrude into the core of the system around 48 hours and will completely engulf the system by around 60 hours. The system will be effectively decapitated and by 72 hours, the remnant vortex will be capped above 700mb by a deep layer of extremely dry air.

As the system rapidly weakens and the vortex shallows out, it will also simultaneously begin subtropical transition (stt) and so it will become a race to see if the system dissipates or completes stt first. Either way, as the vortex shallows it will run directly into a strong ridge to the south and slow down sharply. After 72 hours the remnant vortex will come under the steering influence of the low-level ridge to the south and turn sharply westward prior to dissipating no later than 96 hours.