The Hindu Business Line : Easterly wave comes calling as Bay warms

India Meteorological Department (IMD) has confirmed that conditions are favourable for the onset of northeast monsoon during the next two to three days.

This comes after the announcement that the southwest monsoon has withdrawn from the mainland. Overnight, the northeasterlies have started to behave over the Bay of Bengal.

Arrival of an easterly wave on Tuesday indicates that the ground is being prepared for the onset, says Dr Akhilesh Gupta, Advisor to the Department of Science and Technology. Easterly waves come to pass throughout the year but become frequent and pronounced during the northeast monsoon.

STEERING FORCE

They provide the steering force for northeasterly winds and are capable of dumping heavy showers along the course traversed. Kerala and Tamil Nadu are the two States where easterly wave will have a direct impact. The wave has a wobbly motion and creates some weather only in front.

The air will be absolutely clear in the rear.

This ensures that the worst impact of the weather event will hardly last longer than 24 hours. But the intensity could be so high at times that it creates cloudburst-like conditions. In rare cases, these waves grow to set up cyclones.

There is an organised circulation brewing in the southeast Arabian Sea, off the peninsular tip. This promises to vibe well with a warming Bay, preparing to host a trough of low pressure. This ensemble will further accentuate the south-southeast to north-northeast shear zone (or seasonal trough) of monsoon turbulence.

MODELS CONVERGE

Dr Gupta said at least three respected weather models — the European Centre for Medium-Range Weather Forecasting , the US National Centres for Environment Protection and the Fleet Numerical Meteorology and Oceanographic Centre — concur with this outlook.

The circulation in the southeast Arabian Sea is expected to get organised by the weekend, by when the rain-driving Inter Tropical Convergence Zone would also move in close to the Chennai latitude. Onset of northeast monsoon will take place almost in tandem.

More Stories on : Climate & Weather | Climate & Weather

Article E-Mail :: Comment :: Syndication :: Printer Friendly Page

Stories in this Section
Easterly wave comes calling as Bay warms

Tatas make $10-b bid for Corus

Jet Airways posts Rs 55.1-cr loss in Q2

HDFC Bank net rises 31 pc in Q2

Most indices in red despite Sensex shining

Rain group stocks active on merger plans

Attrition rate at TCS at 10.6 pc

Concor to hike rates by 3-6 pc from Nov

MTNL launches Net TV in Capital

Commodities may recover on tight fundamentals