Editorial
P.V.Anandpadmanabhan
The rainfall over the country as a whole during the second half of the 2014 southwest monsoon season is likely to be 95% of PLA with a model error of ±8%, said Dr Jitendra Singh, Union Minister of State (Independent Charge) for Science and Technology and Earth Sciences,
Dr Singh said the latest estimate suggest the 2014 southwest monsoon season (June to September) rainfall over the country as a whole is likely to be 87% of the LPA with a model error of ±4%
Further elaborating the data the minister said region wise the latest estimate suggest, the 2014 southwest monsoon season rainfall is likely to be 76% of LPA over North-west India, 89% of LPA over Central India, 87% of LPA over South Peninsula and 93% of LPA over North-East India with a model error of ± 8 %.
The minister said this year, the first stage forecast for the season (June- September) rainfall for the country as a whole was issued on 24th April and the update was issued on 9th June. The April and June forecasts for the rainfall over the country as a whole were 95% ± 5 % & 93% ± 4 % of LPA respectively.
Now the forecast for the rainfall over the country as a whole for the second half of the 2014 monsoon season has been prepared by using a new Principal Component Regression (PCR) Model based on 5 predictors. The model error of the 5-parameter PCR model is 8% of LPA. The long period average (LPA) of the rainfall over the country as whole for the second half of the monsoon season (August to September) based on the 1951-2000 period is 43.5cm (49% of the average season rainfall). The coefficient of variation (C.V) of the rainfall time series is 15%.. Hence, there is no need to get panicked, Dr. Jitendra Singh added.
He said the 5-parameter PCR model has also been used to prepare probability forecasts for the pre-defined 3 (tercile) categories of rainfall during the second half of the monsoon season. These are below normal (<94% of LPA), near normal (94-106% of LPA), above normal (>106% of LPA). The tercile categories have equal climatological probabilities (33.33% each). Based on latest rainfall scenario and forecast for the second half of the season, the update for the season rainfall over the country as a whole and four geographical regions have also been prepared.
