Conditions are now favourable for advance of South-West monsoon over Andaman Sea and adjoining seas during the next two to three days. Andaman and Nicobar Islands is the country’s farthest outpost in extreme South-East Bay of Bengal and receives the annual monsoon between May 15 and 20.

MAHASEN EFFECT

Going by this, the onset of the rains is expected to be normal this year, with raging cyclone Mahasen having played a big role facilitating it. It has churned up the seas and is trailed by strong band of southwesterly flows from South of the Equator and heading straight into the Bay of Bengal.

The Thailand Met Department, which is the nearest to Andaman Sea, estimated that southwesterly winds were clocking between 20 and 35 km/hr on Monday. The skies continued to be very cloudy out there with scattered thunder showers, it said. But wind speeds could slow down by the weekend as cyclone Mahasen spun away and died out.

WEATHER WARNING

India Met Department has forecast heavy to very heavy rainfall over Andaman and Nicobar Islands during the next two days.

It also issued a thunder squall warning for East and North-East India as Mahasen clambered in and changed course just to the South towards Bangladesh.

A passing western disturbance under whose influence Mahasen is being forced to make a detour mid-sea towards Bangladesh, would further busy up the weather in the region.

There is also a persisting corridor (trough) of lower pressure extending from North Chhattisgarh to interior Andhra Pradesh.

This would serve as a respectacle for moisture swept in by northeasterly flows from Mahasen, adding to the volatility of conditions.

CYCLONE TRACK

Thundersquall could break out over Jharkhand, Chhattisgarh, Odisha, West Bengal, Sikkim, Assam, Meghalaya, Nagaland, Manipur, Mizoram and Tripura during next two days. Thundersquall has also been forecast over Coastal Andhra Pradesh and Tamil Nadu on Tuesday just as Mahasen executes the about-turn. The Met department located Mahasen centred about 800 km northwest of Car Nicobar and 640 km southeast of Chennai on Monday afternoon.

The cyclone would move initially northwards until Tuesday morning and thereafter recurve towards the Bangladesh/Myanmar coast.

vinson.kurian@thehindu.co.in