Rub-off effect from Pacific sets up Bay churn

Monsoon dynamics are now being influenced by the atmospheric energy derived from the South China Sea, the North-west and Western Pacific.

These contiguous ocean basins to the east of Bay of Bengal are witnessing belated action with a train of tropical storms getting generated in the process.

PACIFIC STORMS

Tropical storm “Mindulle” may have washed ashore on the Vietnamese coast last week, but at least three storms are concurrently raging in these seas.

Of them, “Lionrock” and “Namtheun” have been following a westerly track along the lines of “Mindulle”, which is expected to favourably influence the Indian monsoon.

ATLANTIC ACTIVITY

But Typhoon “Kompasu” has chosen to look the other way heading in the opposite direction (north/north-east) – towards the Korean peninsula and further east.

The “tele-connection” from the east should explain the ongoing activity in the Bay of Bengal, but falling short to ignite activity where it mattered most – the Head Bay.

But the moisture supply and wind pattern have been enough to sustain the rainfall, thanks to the surcharged conditions ensured by the monsoon-friendly La Nina in the East Equatorial Pacific.

Meanwhile, half a world away, the North Atlantic has also woken up to some activity with the Intense Hurricane “Earl” too taking a north to north-east direction to skirt the oil installations in the Gulf of Mexico and barrel into the Caribbean Islands.

FRESH RAINS

International models are suggesting the possibility of a wave of rainfall emerging from the Andhra Pradesh coast and heading west-north-west to cover East Maharashtra, Central, West-central and Northwest Madhya Pradesh and East Gujarat over the next few days.

This will happen as a fresh low-pressure area forms over West-central and adjoining Northwest Bay of Bengal by the weekend. Chances are this could be followed by another in the next week.

FOR NORTHWEST

Parts of Northwest India could be heading for another wet session by the weekend and into the next as monsoon easterlies from the Bay interact with a westerly trough (western disturbance) entering from across the border.

In this context, the behaviour of Bay of Bengal and cyclogenesis (formation of weather systems) would be watched with interest.

An India Meteorological Department (IMD) update for the 24 hours ending Wednesday morning said widespread rainfall was reported from Konkan, Goa, Saurashtra, Kutch and Coastal Karnataka.

It was fairly widespread over Madhya Pradesh, Vidarbha and Andaman and Nicobar Islands.

The seasonal monsoon trough, an upper air circulation in the lower levels over Northwest Madhya Pradesh and East Rajasthan and an upper air cyclonic circulation sitting over Gujarat have been the main systems driving the rains.

Satellite imagery on Wednesday showed the presence of convective (rain-bearing) clouds over parts of Assam, Arunachal Pradesh, West Uttar Pradesh, Central and Southeast Bay of Bengal, North Andaman Sea and Northeast Arabian Sea.

A rain alert issued by the IMD has warned of isolated heavy to very heavy rainfall over Konkan, Goa and South Gujarat on Thursday and over Andaman and Nicobar Islands during the next two days.

Forecast until Saturday spoke about the possibility of fairly widespread rain or thundershowers over Uttarkhand, West Uttar Pradesh, East Rajasthan, Gujarat, Madhya Pradesh, Coastal Karnataka, Kerala and Andaman and Nicobar Islands.

Scattered rain or thundershowers has been forecast over Himachal Pradesh, Bihar and East Uttar Pradesh during the next 24 hours and increase thereafter.

Scattered rain or thundershowers would occur over Chhattisgarh, Orissa, Coastal Andhra Pradesh, Telangana and Vidarbha during the next two days and increase thereafter, the IMD said.