Bay ‘low’ forms, tipped to intensify as depression

Vinson Kurian

Thiruvananthapuram, May 22 A monsoon ‘low’ has formed over east-central Bay of Bengal on Friday which India Meteorological Department (IMD) put under watch straightaway for signs of intensification as a depression.

International models, led by the US Navy’s Joint Typhoon Warning Centre (JTWC), expected the system to churn up eventually as a tropical cyclone with a prospective landfall over West Bengal/Bangladesh early next week.
FAIR POTENTIAL

The JTWC upgraded to fair the potential for development of a tropical cyclone in the Bay basin due to improved consolidation of the low level circulation centre (storm nucleus) and increased convection.

The system is located in an area of favourable sea surface temperatures and low vertical wind shear. Satellite imagery showed a slowly consolidating monsoon depression around 500 nautical miles (926 km) south of Kolkata.

However, the circulation is somewhat elongated and weak at the centre. Stronger southwesterlies flank the southern periphery of the circulation, while weaker easterlies close off the circulation to the north.

CLOSE WATCH
Meteorologists are keeping a close eye on the building storm which they fear could cause the monsoon to forfeit the ‘early onset’ advantage for northward progression to upcountry region in the peninsula.

The away-movement of the Bay system would take with it available moisture in the monsoon system until such time as it makes an eventual landfall and fades out.

The Arabian Sea flows would then have to reconverge to set up a second monsoon ‘pulse’ and drive rains into the peninsular interior (north interior Karnataka, Maharashtra, Rayalaseema and Telangana).

“This is expected to happen within four to five days given the trigger mechanism available in the form of the overarching Madden-Julian Oscillation (MJO) wave in the upper levels. It’s just a question of when,” says Dr Akhilesh Gupta, operational forecaster with the Department of Science and Technology.
NO WORRY

Thus, there would be no time gained or lost as rejuvenated monsoon sets about covering the rest of the peninsula. Farmers in upcountry regions need not worry about the arrival of seasonal rains, if these projections are to be believed.

The IMD said in its update on Friday said that the monsoon has further advanced into parts of south Arabian Sea, south and central Bay. Conditions are favourable for onset over Kerala during next two days.

Conditions are also favourable for further advance into more parts of south Arabian Sea, extreme south peninsula, remaining parts of the south Bay and parts of the central Bay.
http://www.thehindubusinessline.com/2009/05/23/stories/2009052350541600.htm