The Kerala coast awaits a strong onset of the monsoon as erstwhile extremely severe cyclone 'Mekunu,' the sole hurdle on its way, fades out over Oman. The monsoon onset is promising to be a spectacular affair as both the Arabian Sea and the Bay of Bengal are on a song concurrently, a setting not witnessed during recent past.

Getting into act

Not least so after two back-to-back cyclones have ravaged the Arabian Sea, leading to the loss of kinetic energy into the away-going storms, of which one was an extremely severe cyclone. If India's peninsular seas are still able to get their act together, it only goes to establish the strength of the monsoon, overseen by a Madden-Julian Oscillation (MJO) wave from above.

The periodical wave that traverses the Indian Ocean has again demonstrated how it can underwrite storm formation and monsoon onsets under its footprint.

Model forecasts continue to suggest that the eastward moving MJO wave would now be active over Central Indian Ocean and the Bay of Bengal until June 8. As if on cue, India Met Department (IMD) has already forecast the possibility of a low-pressure area forming in the East-Central Bay in two days' time.

‘Twin engines’

The monsoon has already entered the South Andaman Sea in the South-East Bay and conditions are favourable for its further advance, the IMD has said. Things are fast evolving also over the South-East Arabian Sea off the Kerala-Karnataka coast where another 'low' is likely to pop up soon under the influence of strong flows.

This would make for a rare sight of a monsoon powered by 'twin engines' on either side of the peninsula and propelling its way through a singularly spectacular onset phase. According to the ensemble model of the US National Centres for Environmental Prediction, the 'low' in the Bay could travel towards Myanmar-Bangladesh next week.

It would also send in South-Easterly winds into the North-Eastern States of adjoining India, and could spin up another circulation in its wake later, off the Andhra Pradesh coast. On the other side, the forecast 'low' in the Arabian Sea would ensure that the monsoon drives along smoothly along India's West Coast.

Heavy rain forecast

The Thiruvananthapuram Met Office has warned heavy to very heavy rains in parts of the state today and tomorrow in view of the building strong flows in the Arabian Sea. The proceedings would escalate on Monday when it has forecast heavy to very heavy rain and isolated extremely heavy rain as the monsoon approaches for the onset.

A similar forecast is held out for Tuesday, the median date of onset with a window of four days to either side, and extends to Lakshadweep as well. It would not be surprising though if the strength of the monsoon flows prompt the IMD to advance the monsoon onset to any day before.

Squally weather has been forecast over the Comorin region, Lakshadweep, Kerala-Karnataka coasts over the next four to five days. Fishermen have been advised not venture into the seas off the South Tamil Nadu, Kerala and Karnataka coasts and Comorin region for five days until Wednesday next.