NEW DELHI: India is forecast to get an overall ‘normal’ monsoon rainfall this year, but an initial month-wise prediction suggests ‘below normal’ rainfall during June, long dry spells in July and the rains then making up with ‘excess rainfall’ during August and September — almost similar to last year’s pattern, says an internal assessment note available with the government.
Though the India Meteorological Department’s (IMD) forecast for spatial and month-wise distribution of monsoon is still a month away, the note shows that coastal region of Odisha, West Bengal and Mizoram may get ‘below normal’ rainfall while southern part of Tamil Nadu and Kerala are expected to receive ‘above normal rainfall’.
The note, carrying map on spatial forecast on monsoon, shows near normal rainfall with 40-50% probability for large part of the country. It indicates near normal rainfall for Gujarat, Rajasthan, western part of MP and northwestern part of Maharashtra with a probability of 50-60%.
The IMD had on April 15 predicted normal rainfall (96-104% of long period average) with a model error of ± 5% over India during southwest monsoon season (June to September). The long period average of the season rainfall for the period 1961-2010 is 88cm.
The country’s national weather forecaster, however, didn’t then speak about spatial distribution of rainfall as this aspect is predicted only in May last week or June first week.
Later, the South Asia Seasonal Climate outlook Forum (SASCOF) - which involves various international agencies led by WMO - too indicated normal rainfall for large part of the country and the forecast is almost in line with that of IMD.
“While IMD provides probabilistic estimates of seasonal rainfall for the India as a whole, other agencies provide spatial information on probabilistic rainfall for India/South Asia. These spatial maps for the country and states are extracted from South Asia maps by superimposing map of India with state boundaries,” says the note.
Referring to the forecast map, the note also talks about possibility of dwindling rainfall in June and July in rainfed regions of Andhra Pradesh, Karnataka, Telangana, Marathwada and Vidharbha regions of Maharashtra, which may impact rainfed crops.