Monsoon forecast: India to receive 102% of average rainfall between June, September

India Meteorological Department on Monday announced that the country would receive 102 per cent of its average rainfall between June and September this year.

The announcement comes within hours of the south west monsoon reaching the Kerala coast, four days ahead of its scheduled date.

The north-west, central and peninsular India is to be showered with 107 per cent, 103 per cent and 102 per cent of average rainfall respectively but the precipitation would be little less for north-east India which would get 96 per cent of the average rainfall.

India’s long period average rainfall is 88 cm, which is the average monsoon rainfall between 1961 and 2000. For the whole country, the error margin is 4 per cent, which goes up to 8 per cent for the region.

The July rainfall - crucial for India's trillion dollar economy that rides high on farm productivity - would be 103 per cent of the average while rainfall will go down a bit in August as the IMD six-parameter statistical monsoon model predicts 97 per cent of the rain.

Even the probabilistic calculations favour a normal monsoon. There is 41 per cent probability of a normal monsoon (96-104 per cent of the LPA); 25 per cent probability of above normal monsoon (104-110 per cent of LPA) and 14 per cent probability of excess (above 110 per cent) monsoon. Taken together, there is 80 per cent chance of the monsoon being a normal or above normal one.

"The probability distribution is skewed towards the positive side. It's good news," said M Rajeevan, Secretary, Ministry of Earth Sciences.

The June update of the IMD's long range weather forecast is an improvement from the weather bureau's April forecast when it announced that the country would cumulatively receive 100 per cent of its average rainfall in these four months.

A dynamical experimental model developed by the IMD under the monsoon mission also producten normal rainfall (107 per cent of the LPA with 4 per cent error margin).

Rajeevan ruled out any threat from the El Nino (an unusual warming of the Pacific sea surface temperature that plays havoc with weather systems around the world).

Either a cold ENSO (El Nino - Southern Oscillation) or weak La Nina conditions (opposite to El Nino and beneficial to monsoon) are likely to persist during the season.

On the cyclonic storm that is brewing in the Arabian Sea, IMD director general M Mahaputra said the existing deep depression will be transformed into a cyclonic storm that would hit the coast at a velocity of nearly 100 kmph on June 3 impacting coastal districts of Maharashtra like Sindhudurg, Raigad, Mumbai, Thane and Ratnagiri, as well as south Gujarat.

While Maharashtra and Gujarat are the two states that are to be impacted by the severe cyclone, the exact landfall areas would be known by Tuesday morning, he said. Coastal Karnataka and north Kerala would also experience high speed winds, rains and rough sea.