A fresh low-pressure area has developed over land along the coastal areas of Odisha with the potential of revving up monsoon yet again.
Formation of ‘low’ over land (unlike seawaters in the normal case) is itself a statement on the strength and intensity of a prevailing monsoon.
MOISTURE FEED
Seawaters ensure sufficient moisture feed for the systems through ocean warmth and resultant convection. Normally, the systems weaken on washing ashore and hitting dry land.
But here, the atmosphere is itself awash with moisture, helping in the formation of the ‘low’ and sustaining feed into the system (akin to aircraft refuelling mid-air).
It is even forecast to undergo intensification and move towards the Jharkhand-Gangetic West Bengal over the next few days.
There is also the ‘pull power’ exerted by Typhoon Soulik in West Pacific, which is racing in for an eventual landfall over Taiwan.
STRONG MONSOON
Soulik’s strength (next only to class-topping category 5 on the Saffir-Simpson scale of intensity) is drawing in moisture from both the Arabian Sea and the Bay of Bengal.
This explains why the monsoon continues to be very strong along the West Coast, represent best by the offshore trough extending all the way from Gujarat down to Kerala.
US forecasting agencies said a weather-boosting Madden-Julian Oscillation wave was currently active over the Indian Ocean region.
This wave periodically travels in the upper air across the Indian Ocean but has a major influence on ground weather thanks to its ability to generate clouding and storms. Most of the country, starting from South into Central India, would be brought under the influence of the wave during the next seven days.
This is even as international agencies declared that a negative Indian Ocean Dipole, a temperature anomaly, has set in over the Indian Ocean.
Augurs well
This was thought to be a bad augury for the Indian monsoon, but has since come to be eclipsed by prodigious flows facilitated by favourable conditions in the East Pacific.
Heavy to very heavy rains are expected over East and East-Central India, the West Coast and parts of West and Northwest India.
Still, large parts of peninsular India, especially to the east, might not benefit from an expectedly productive session.
vinson.kurian@thehindu.co.in