After a wait that lasted more than a week, the monsoon has managed to resume its northward journey from Karwar, Chikamagaluru, Bengaluru in Karnataka by Friday evening and covered entire Goa, some parts of Konkan and some more parts of Karnataka, India Meteorological Department (IMD) said in an update.
This came about even as the cumulative rain deficit over South Peninsula rose to 36 per cent as on Friday after the monsoon arrived over Kerala 13 days ago (on May 29). The deficit is highest in Telangana (-72 per cent), followed closely by Coastal Karnataka (-71 per cent); Kerala (-61 per cent); Coastal Andhra Pradesh (-41 per cent); and Lakshadweep (-30 per cent).
Mixed fortunes so far
Among other meteorological subdivisions in the South Peninsula, some fell fresh into deficit category while others saw deficits rise from last week. These are Rayalaseema (-11 per cent); Tamil Nadu and Puducherry (-6 per cent); and North Interior Karnataka (-2 per cent) while South Interior Karnataka saw the rain surplus being cut down to just 5 per cent. The progress of the monsoon itself has been flawed thanks to an unusual easterly bias bringing rains to Tamil Nadu, Puducherry and Rayalaseema while giving the West Coast (Kerala and Coastal Karnataka) a miss.
This is in turn being attributed to the lack of either a supportive cyclonic circulation (onset vortex) over the South-East Arabian Sea or the all-important offshore trough along the West Coast, a trademark monsoon feature. This has not allowed the usual convergence of monsoon flows that brings associated burst of rainfall.
Monsoon left on its own
The core underlying reason for an under-performing monsoon is apparently the unforgiving attitude of the atmosphere above the Indian Ocean. It has not allowed a friendly Madden-Julian Oscillation (MJO) wave to travel from West to East over the Arabian Sea and the Bay of Bengal helping set up moisture and clouds.
There is no sign of the wave approaching Indian Ocean in the next two weeks either, per the IMD. This leaves the monsoon to power itself on its own dynamics, which is taking time, after a deep western disturbance travelling in the same direction over North/Central India stalled its onward progress from Sri Lanka.
May align better, strengthen
The IMD said conditions are now favorable for the monsoon to enter some more parts of South Maharashtra, Karnataka, remaining parts of Tamil Nadu and some parts of South Andhra Pradesh during next two days. In the subsequent two days, it is likely to check into more parts of Maharashtra, entire Karnataka and more parts of Andhra Pradesh.
The ongoing week (June 9-15) will see fairly widespread or widespread or light/moderate rain, thunderstorm and lightning over Karnataka, Kerala, Mahe and Lakshadweep. It will be scattered to fairly widespread over Andhra Pradesh, Tamil Nadu, Puducherry and Karaikal and Telangana during most days of the week.
Heavy rain forecast
Isolated heavy rainfall is forecast over South Interior Karnataka on Sunday; over Coastal Karnataka until Monday; and over Kerala on Saturday and Sunday. Fairly widespread to widespread rainfall with thunderstorms, lightning and gusty winds are likely over Konkan and Goa (including Mumbai) and scattered to fairly widespread with thunderstorm, lightning and gusty winds over Madhya Maharashtra and Marathwada during most days of the week. Isolated heavy rain is likely over Konkan and Goa on Friday and Monday and isolated very heavy on Saturday and Sunday.