International weather models expect a persisting low pressure area in the Southeast Bay of Bengal to start intensifying during the next 24 hours.
The India Meteorological Department has already put out a watch for its strengthening as a ‘monsoon depression,’ just a couple of turns away from being declared a cyclone.
‘HIGH’ CHANCE
The US Navy traced the path traversed by the system as the parent cyclonic circulation from the Southwest Bay of Bengal to the Southeast where it is currently parked.
It has upgraded to ‘high’ chances of its intensification, and, to start with, appeared to suggest a west-northwestward movement into the East-central Bay of Bengal.
The point of landfall projected now ranges between the Odisha-West Bengal coasts in India to Bangladesh-Myanmar in the Bay of Bengal rim off the international border.
Earlier, the storm was forecast to start moving in from Southwest Bay of Bengal, prompting forecasters to suggest India’s East Coast (Andhra Pradesh-Odisha) as the landfall point.
STORM ALERT
The movement to the Southeast Bay happened later, and necessitated recalibration of the likely landfall point.
Meanwhile, a hazard warning analysis from the Climate Prediction Centre of the US National Weather Services has also indicated formation of a tropical cyclone in the Bay of Bengal over the next few days.
It suggested its northward movement from just East off Sri Lanka (which stands corrected to off the Sumatra Island since) to the Northeast Coast of India (Odisha-Gangetic West Bengal).
The US Navy’s Joint Typhoon Warning Centre said the storm might run into a hostile vertical wind shear (sudden change in winds speeds with height) environment.
WIND SHEAR
High wind shear values lop the top off the storm tower (which extends km-high into the atmosphere) and weakens it, leading to its collapse and untimely death.
But the US agency forecast suggested that the vertical shear is more than made up by the low-level flows from the northern and southern semi-circles, allowing the storm to hold on.
High sea-surface temperatures are helping convection (evaporation, moisture formation and cloud-building) to flare up, leading to strengthening of the storm.