Rains to stay, but N-E monsoon onset to take longer

Vinson Kurian Updated - October 20, 2018 at 11:16 AM.

Satellite image taken on October 20, 2018 (09.45 IST) Source: IMD

The countdown may have started but it would take longer to announce the onset of a canonical North-East monsoon, according to sources in India Met Department (IMD).

This, however, is not to deny the probability of rainfall over the South Peninsula next week rounded off by by the formation of a low-pressure area.

Rains sans monsoon

Also, withdrawal of the South-West monsoon, which has overstayed its tenure, should be complete over the next two days. This should normally leave the space for the North-East monsoon, but not just yet.

This is being attributed to some 'extra-territorial anomalies' involving a high-pressure area farther to the latitudes North of Asia, which actually steers the North-East monsoon flows.

Wind-field projections of the IMD too suggest that the easterly winds over entire Peninsular India would achieve peak strength only after October 25.

But that will not prevent rains from lashing the South Peninsula falling under the footprint of the North-East monsoon during the emerging week.

The US National Centres for Environmental Prediction suggests that organised rainfall that heralds the season would begin only after October 27,  more than a week behind the normal onset window.

Circulation under watch

The IMD said last night that conditions are becoming favourable for withdrawal of the South-West monsoon from the entire country latest by tomorrow.

This would also mean that conditions may become favourable for the North-East monsoon thereafter.  There is no simultaneous switchover this time round, though.

The IMD also pointed to a persisting cyclonic circulation over the Gulf of Thailand, just across the South-East Bay of Bengal.

This is expected to emerge into the North Andaman Sea and under its influence, a low-pressure area is likely to form over North Andaman Sea and neighbourhood by Monday.

The IMD does not see the 'low' gaining much traction since its movement is forecast to be wobbly. The European Centre for Medium-Range Weather Forecasts tends to agree with it lately.

The latter now sees the possibility of a system developing closer to the Tamil Nadu-Sri Lanka coasts by October 30, which should help intensify the North-East monsoon.

Published on October 20, 2018 05:34