There are early signs of the first tropical storm of post-monsoon season coming up in the Arabian Sea. Feeble perturbation is likely to precede the main system anytime soon. Mid-October and later is a favourite and preferred period for evolving cyclones over the Indian Seas. Cessation of active monsoon current reduces the churning of layers and increases the sea surface temperature. A rise in the heat potential triggers cyclogenesis on either side of the Indian coastline, more so, from mid-October to mid-December.
There is a cyclonic circulation lying over the Southeast Arabian Sea and the adjoining Lakshadweep region. Under its influence, a low-pressure area is likely to form over the same region in the next 24hours. Such weather systems being very low in latitude have to fight against many odds to sustain and grow. After crossing the initial hurdles, further prediction and prognostication become relatively smooth.
The low-pressure area, once established, is expected to organize well and intensify into a depression over the southern parts of the central Arabian Sea. Gaining latitude becomes very essential for further intensification. Any perturbation crossing 15°N and locating west of 65°E stands a fair chance of intensifying into a tropical storm. Further track of these systems is governed by the steering current in the higher levels of the atmosphere and the position of the sub-tropical ridge.
There is no model consensus, as of now, for the clear formation of cyclones. Climatology and sea conditions are not a deterrent, to start with. A window of another 2 days will bring clarity and release the ‘fog’ on the formation of the maiden cyclone, post-withdrawal of monsoon. No tropical storm formed over the Arabian Sea during post-monsoon 2022. Whereas, the Bay of Bengal witnessed two tropical storms, Sitrang and Mandous. Therefore, the statistical probability of cyclone formation in the Arabian Sea becomes higher. The tropical storm, if forms, in the Indian Seas, will be named ‘Tej’.
Such cyclones in the Arabian Sea have a dubious history of track and timelines. These storms keep the meteorologist struggling to decisively predict their further sea travel. Once over the central parts of the Arabian Sea, the more preferred track is to head for Somalia, Gulf of Aden, Yemen and Oman. But on a few occasions, these cyclones take a detour and head for Gujarat and Pakistan coastline. The Arabian Sea will remain under close observation for the development of an exclusive storm of this season.