Weekly Tropical Climate Note

Cyclonic storm Vayu forecast to strengthen

In the Indian Ocean, cyclonic storm Vayu was located about 630 km south-southwest of Mumbai at 04:00 AEST this morning, heading north-northwest. Vayu is expected to strengthen to severe cyclonic storm strength and cross Gujarat's coast in western India early Thursday morning with wind speeds between 110–120 km/h.

See the India Meteorological Department website for more information.

Slow progression of southwest Indian monsoon

The southwest Indian monsoon continued its advance northwards this past week. However, it is still further south than usual, with the India Meteorological Department reporting that the northern limit of the monsoon had arrived at only the southern states of Kerala and Tamil Nadu. Usually by this time of year the northern limit of the monsoon has reached central India.

Madden–Julian Oscillation weakens over Indian Ocean

The Madden–Julian Oscillation (MJO) waned last week over the Indian Ocean and has subsequently had only a weak influence on tropical weather. There are some differences between the various MJO model outlooks for this coming week, but the consensus is for the MJO to continue eastward and strengthen over the Maritime Continent. Typically, when the MJO is active over the Maritime Continent at this time of year it can enhance convection around the Bay of Bengal, and parts of Queensland and the Maritime Continent. If the MJO does strengthen over the Maritime Continent it could also contribute to the advance northwards of the southwest Indian monsoon.

Read more about the Bureau's MJO monitoring.