India Meteorological Department (IMD) has announced that the North-East monsoon rains may commence over the South-East Peninsula (Coastal Andhra Pradesh and Tamil Nadu) on Saturday after the north-easterly wind regime establishes over the Bay of Bengal. A helpful cyclonic circulation lies over West-Central and adjoining South-West Bay of Bengal to steer the winds and a trough running from the South-West Bay to South Interior Karnataka across Tamil Nadu will bring them in towards the coast. 

‘Sitrang’ delays onset by a week

The IMD has forecast scattered to fairly widespread light to moderate rainfall with isolated heavy falls, signature thunderstorms and lightning over Tamil Nadu, Puducherry and Karaikal on Saturday and Sunday and over Coastal Andhra Pradesh, Yanam, Rayalaseema, Kerala and Mahe on Sunday. Isolated very heavy rainfall is likely over Tamil Nadu, Puducherry and Karaikal on Sunday. 

The onset happens at least a week late, thanks to the rogue cyclone ‘Sitrang’ that spun away from Tamil Nadu and Andhra Pradesh coast and made landfall over the Bangladesh coast on Tuesday, driving away the flows. They are getting reorganised faster than thought, though dwarfed by a brewing typhoon in the upstream West Pacific. Models see the powerful typhoon to the East of the Philippines recurving farther away beyond the Koreas and Japan during the weekend.

Also read
Harvest of pulses isn’t keeping up with the production target

Concern over pulses

Typhoon impact on flows

Back home, the IMD said that in addition to the persisting cyclonic circulation over the West-Central Bay, a fresh one may develop over the East-Central Bay during the week of October 27 to November 2, coupled with a rain-friendly easterly wave. The north-easterly wind regime is seeking to use this window of opportunity, but would likely be enfeebled by the prodigious outgo towards the building Pacific typhoon.

It is, however, projected that the circulation over the West-Central Bay could persist for the next five days and convert itself as the rain-head upfront of the incoming easterly wave that will alter the situation and boost rainfall along the Andhra Pradesh and Tamil Nadu coasts.

Rain boost likely 

The IMD has already said in its extended forecast that the easterly wave could trigger light to moderate scattered to fairly widespread rainfall over most parts of the South Peninsula during the week starting Thursday. Isolated heavy rainfall is also likely over the South-East Peninsula (mainly coastal Andhra Pradesh and adjoining Tamil Nadu) during many days of the week.

Overall, rainfall activity is likely to be near normal over most parts of the South Peninsular; near normal over East and North-East India and below normal over North-West and Central India during the week. The IMD said on Wednesday that a remnant cyclonic circulation hovered over South Assam and the neighbourhood on the morning after erstwhile cyclone ‘Sitrang’ crossed the Bangladesh coast.

Related Topics
comment COMMENT NOW