New Delhi, April 23: A poor-performing summer monsoon may be among the earliest challenges for the new government that takes over in May this year, a joint analysis of multiple forecasts by Indian and international weather scientists has indicated.
The analysis has suggested that the 2014 summer monsoon rainfall is likely to be below normal across western, northern, central and southern parts of the country, the India Meteorological Department (IMD) said today.
Releasing a “consensus statement” that emerged from the analysis, the IMD said some parts of eastern India and the island zones could receive normal rainfall. But the exercise has not labelled “above normal” as likely anywhere in southern Asia.
The scientists who pooled weather simulations from Indian, European, Japanese and US agencies believe that an anticipated rise in the sea surface temperatures in the Pacific — the phenomenon called El Nino — are portents of a poor-performing monsoon.
Climatological studies in the past have shown that El Nino translates into a poor summer monsoon for India.
“But every El Nino year need not be a bad monsoon year,” D. Sivananda Pai, the head of the long range forecasting division at the IMD Pune told The Telegraph. Several other regional and global factors also affect the monsoon.
One such factor is the snow cover over the northern hemisphere. The snow cover during winter and spring has a negative relationship with the monsoon over India — the lower the snow cover, the higher the overall rainfall.
The northern hemisphere snow cover during the winter of 2013 was normal to slightly above normal, but the snow cover during March 2014 is the sixth lowest snow cover during March in the past 48 years.
“There are still some uncertainties — things will get a little clearer over the next month,” Pai said.
The IMD is expected to issue its preliminary long range forecast for 2014 tomorrow.
But the joint analysis conducted at a scientific meeting hosted by IMD Pune this week has indicated that western, central and northern India will have a 45 per cent probability of below normal rainfall, a 35 per cent probability of normal rainfall and 20 per cent probability of above average rainfall.
The exercise has suggested that eastern India has a 35 per cent probability of below normal rainfall, 40 per cent for normal rainfall and 25 per cent for above normal rainfall.
The IMD is expected to issue a detailed long range forecast in early June with specific predictions for western, southern, eastern and central India.
“We take into account new sea surface temperature and wind data from the Pacific ocean,” Pai said.
The consensus statement issued last year for the 2013 monsoon had correctly predicted normal rainfall with a slight tilt towards the higher side of normal.
India had last year received normal — 106 per cent of the long period average — rainfall, after a prediction for 98 per cent rainfall, also within the normal range.
The consensus statement is based on joint analysis of weather simulations by Indian and several foreign agencies — the UK Meteorological Office, the US National Centers for Environmental Prediction and the Japan Agency for Marine-Earth Science and Technology, among others.