August deficit brings seasonal rainfall deficit for all of India to -9%
New Delhi, September 1 (IANS): Despite a delayed start to the monsoon, rainfall in June was above normal, July showed signs of a deficit with a slight variation, but it was the overall deficit of 24% in August that pushed the seasonal rainfall of monsoon season across India from June 1 to August 31 at nine percent below normal, IMD said on Wednesday.
Compared to the normal precipitation of 258 mm, the observed precipitation in August was only 195.9 mm, a whopping 24% deviation from the long-term average, said the director general of the meteorological department of the India, Dr Mrutyunjay Mohapatra, at a press conference.
The IMD calculates the long-term average (LPA) based on data for years between 1961 and 2010.
Equally erratic was the spatial variation in precipitation in the four homogeneous regions of India. Despite a weak June and a very negative month in July, only the east and northeast posted slightly positive results, and the other three – northwest India, central India and the India’s southern peninsula all experienced deficit rainfall.
According to IMD data, Northwest India received 140.6mm vs. normal 202.7mm (start (-) 30.6%), East and Northeast India received received 354.4mm vs. normal 346.0mm (baseline 2.4%), Central India received 186.8mm vs. normal precipitation of 307.3mm with a deviation of (-) 39 percent – the most negative of the four – while India’s southern peninsula received 169.4mm of rain versus the normal 188.7mm (starting (-) 10.2 percent).
The lack of precipitation also had its impact on the days of extreme rain, the number of stations reporting very heavy (between 115.6 mm to 204.5 mm) and extremely heavy (over 204.5 mm) precipitation was considerably less than in recent years.
In 2017, up to 401 stations recorded very heavy precipitation while extremely heavy precipitation was recorded at 90, in 2018, 510 stations recorded very heavy stations while extremely heavy were recorded by 96 stations, in 2019, the number increased to 987 for very heavy and 282 for extremely heavy), 2020 continued the trend with 1,008 stations recording very heavy rain and 165 stations recording extremely heavy precipitation. However, in 2021, only 272 stations recorded very heavy rainfall and only 28 stations recorded extremely heavy rainfall, IMD data showed.
“IMD had predicted ‘below normal’ precipitation over many parts of central India, J&K, Ladakh, HP and Punjab and ‘normal to above normal’ precipitation over many parts of southeastern India. India, northeast India, Himalayan foothills, northwest MP. All of these have been correctly predicted. However, the “below normal” precipitation observed in many parts of Gujarat, Odisha and the west coast could not be predicted, ”admitted Mohapatra.
He said most of the rainfall deficits in August are associated with negative El Niño / IOD (Indian Ocean Dipole) events, a condition resulting from the difference in sea surface temperatures at different locations in the Indian Ocean) visible in nine of the 15 years of the PLA.
Of the 15 deficit years in August (deficit of 15 percent or more) between 1965 and 2020, seasonal precipitation was insufficient in nine years, below normal in two years and the other four were normal years, according to the researchers. IMD data.
Mohapatra said: “In recent years, there has been a large deficiency ((-) 24.8 percent LPA) observed in August precipitation in 2005, but the seasonal precipitation was in the normal category. year 2001 also observed a deficiency of (-) 20.1 percent of LPA but the seasonal precipitation was below the normal category (92.3 percent of LPA). These two cases of negative IOD event were observed on Indian Ocean.