The country is likely to receive its full share of the estimated long-period average (LPA) rainfall during the crucial month of July but only 94 per cent in August, both with a model error of ± 9 per cent.
The projected deficit in August could have implications for the early stage kharif crops. The month-wise outlook was put out in India Met Department's (IMD) second-stage long-range forecast for the South-West monsoon that set in over Kerala yesterday. The expected early onset of the rain in the South Peninsula and adjoining Central India should help with the kharif sowing. The IMD has not come out with a forecast for June, but most global models are of the view that it would be either normal or slightly in excess.
Monsoon advance
The US National Centres for Environmental Prediction see the Bay of Bengal remain in an active phase for the next 12 to 15 days, generating low-pressure areas or depressions.
This is as it should be, since it devolves on the Bay to sustain the monsoon after the onset phase since any system forming in the Arabian Sea is vulnerable to moving away from the West coast.
These systems are forecast to brew either in the Head Bay (around Kolkata) or the Odisha or Andhra Pradesh coasts, an outlook shared by the European Centre for Medium-Range Weather Forecasts.
The IMD too has assessed that conditions are favourable for further advance of the monsoon into some parts of the North-Eastern states during the next two days.
Normal in N-W
Seasonal rains may enter more parts of the South Peninsula from Sunday, with the likely development of favourable circulation over the seas. This would lead to an increase in rainfall over interior Tamil Nadu, Andhra Pradesh and Telangana. Rains may scale up over parts of Maharashtra and Goa from Wednesday next. The IMD reiterated that rainfall over the country as a whole for the June-September season to be most likely normal (96 per cent to 104 per cent of LPA).
Quantitatively, the rainfall is likely to be 97 per cent of the LPA with a model error of ±4 per cent. Region-wise the seasonal rainfall would be 100 per cent of LPA over North-West India 99 per cent over Central India, and for South India, 95 per cent.