Severe Tropical Cyclone Courtney 2025

Live tracking map, satellite images and forecasts of Severe Tropical Cyclone Courtney 2025 in the South Indian Ocean. Current wind speed 220km/h.

Courtney is located 904 km southwest of the Cocos Islands, and has tracked west-southwestward at 20 km/h (11 knots) over the past 6 hours. Maximum significant wave height is 12.8 meters (42 feet).

Courtney will continue to track along the northwestern side of the subtropical ridge to the southeast and trace a graceful left turn, such that in 2 days 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 over the next 24 hours will be the potential eyewall replacement cycle.

The CIMSS M-PERC is currently predicting a 50% chance of an eyewall replacement cycle, and based on the SBC seen in the microwave imagery, it is likely that eyewall replacement cycle will in fact begin within the next 12 hours or so.

Intensity will drop rather quickly once eyewall replacement cycle begins and due to an expected sharp increase in shear beginning after 24 hours, it is unlikely that the eyewall replacement cycle will be able to complete the cycle and the system will not recover.

Shear is forecast to exceed 65 km/h (35 knots) in 36 hours and only increase thereafter. Extremely dry air begins to intrude into the core of the system in around 2 days and will completely engulf the system by in around 60 hours.

The system will be effectively decapitated and in 3 days, the remnant vortex will be capped above 700 hPa 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 3 days the remnant vortex will come under the steering influence of the low-level ridge to the south and turn sharply westward prior to dissipating in 4 days.

Deterministic track guidance is actually in fairly good agreement over the next 3 days, with a 306 km cross-track spread at the end of that time point.

The NAVGEM and GFS continue to turn the system south and southeast at a faster rate than the other models and thus mark the eastern edge of the guidance envelope.

The ECMWF-aifs takes a wider turn and marks the western edge. The remainder of the consensus members are confined to a tight grouping centered on the consensus mean.

The JTWC forecast is hedged towards the western side of the inner grouping of the models, with high confidence over the next 3 days. After 3 days, the models begin to disperse, with cross-track spread opening up to over 482 km between the GEFS mean on the west side and the EC-aifs on the east side.

The JTWC forecast most closely follows the GFS and consensus mean after 3 days, with low confidence. Intensity guidance is in good agreement with moderate to rapid weakening through the forecast period.

The JTWC forecast is set close to the HAFS-A and slightly above the consensus mean through the forecast period with medium confidence.