As a well-marked low-pressure area over South-West Arabian Sea (away from Kerala-Lakshadweep) is on course to become a depression, all eyes are focused on a cyclonic circulation nearer home.

India Met Department (IMD) had said last night that the well-marked 'low' could become a depression today and head into the Gulf of Aden, nestled in between South Yemen and Somalia in East Africa.

Fresh development

Most global models are in agreement, with the Joint Typhoon Warning Centre locating the 'low,' tagged as '91A' (A for Arabian Sea) to the South-West of Socotra Island off Yemen.

Meanwhile, a persisting circulation over South Tamil Nadu and adjoining Comorin might warrant close scrutiny given its potential for further development over Lakshadweep, off the Kerala coast.

Models initially thought it might move further away from these coasts, but expected arrival of a western disturbance over North-West India and North Arabian Sea has occasioned second thoughts.

Opposing winds from the disturbance might stall this away-movement, and cause the system to head North (as against West-North-West) and enter East-Central Arabian Sea by May 25.

Monsoon onset?

It is to be seen whether the system, intensifying a round as it enters East-Central Arabian Sea, could drag the South-West monsoon along with it and precipitate an onset along Kerala coast.

This is because the rapid developments in the Arabian Sea are being underwritten by a passing Madden-Julian Oscillation (MJO) wave, which has triggered monsoon onsets in the past.

Also, there are indications that the monsoon may break five to seven days ahead of the normal date of June 1 over Kerala, a view supported by private forecaster Skymet.

This is even as the official announcement of the date of onset by the IMD is awaited. The persisting circulation over the Comorin assumes significance in this context.

The European Centre for Medium-Range Weather Forecasts sees the intensified form of the circulation lying equidistant from the Oman coast and India's West Coast by May 25.

Pre-monsoon showers

Initially, it and other global models had indicated the development of a powerful cyclone, but downgraded it after the likely smothering effect of the western disturbance was factored in.

The European Centre saw winds over the Comorin region and the Lakshadweep Sea ratcheting up in strength over the next four to five days as the circulation prepares to intensify.

Meanwhile, pre-monsoon features over land represented by an array of cyclonic circulations and troughs promise to sustain the dust storms/thunderstorm regime across the country.

A prevailing western disturbance with a successor moving in close on its heels may add fuel to the proceedings over the next three to four days.

The IMD has put most of North-West India, East India and the South Peninsula under notice as these features mature during the course of this period.

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