Comments
The offshore trough of low pressure off the Kerala coast is expected to become pronounced and deep enough by Thursday, to set up ideal onset conditions for the monsoon.
Monsoon intensity is dependent on how well-endowed is the trough, an elongated reservoir in the air where the flows temporarily converge and fan in the moisture mopped up from the sea as rain inland.
Pressure charts plotted by the India Met Department showed that the trough would become even more pronounced by Friday.
Winds had turned helpfully westerly off Thiruvananthapuram by Wednesday noon and were expected to stay so into the night initially. But they had not yet clocked the threshold speed of 27 to 37 km/hr.
India Met Department has still kept a two-day window for the onset, apparently because of a blocking trough over land extending from south-west Madhya Pradesh into interior Karnataka.
Monsoon westerlies will push this trough towards the Seemandhra-Tamil Nadu coast, which should bring in some rain along the east coast also.
The US Climate Prediction Centre forecasts suggest that the west-coast, along with central India, may stay dry during the week ending Monday (June 9).
Kerala and Karnataka coasts, along with interior peninsula and the east-coast, will be likely exceptions. But the entire west-coast will get walloped the week after with Kerala-Karnataka bearing the brunt.
A few models suggested that the Arabian Sea and the South China Sea may host away-going storms. The two basins are crucially situated to either side of India from the monsoon point of view.
Sea-based systems thrive on moisture sourced from the same Asian monsoon flows covering an entire swathe of geography from West Asia to the Far-East.
Storms forming in these basins can divert moisture headed for India unless they are homeward-bound.
In the present instance, the Arabian Sea storm may head for the Gulf of Eden and the South China Sea system towards the Koreas.
Strong flows crossing from the Arabian Sea into the Bay of Bengal will get pulled away by the system brewing in the South China Sea only next door.
This is due to the inability of the Bay to host a strong system that can hold the flows and turn them around towards India’s east-coast and pump in the rains inland.
Comments
COMMENT NOW
Comments
Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.
We have migrated to a new commenting platform. If you are already a registered user of TheHindu Businessline and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.