Rainfall recorded in August lowest in 19 years: IMD
What's the story
Rainfall in August, which recorded 24% deficiency, was the lowest in 19 years, the India Meteorological Department (IMD) said on Friday. Two major spells of weak monsoon prevailed over the country -- from August 9 to August 16 and August 23 to August 27 -- when northwest, central, and adjoining peninsular and west coast of India had subdued rainfall activities.
Details
It is the lowest August rainfall since 2002
During August 2021, rainfall over the country was below Long Period Average (LPA) by -24%. It is also the lowest August rainfall since 2002, the IMD said. "The Southwest Monsoon season officially commences from June 1 and lasts till September 30. The month of June recorded 10% more rainfall, but July and August clocked deficiency of 7% and 24% respectively," IMD said.
Information
Central India division received 39% less rainfall
The country received 24% less than normal rainfall in August. Of the four meteorological divisions of the IMD, the central India division received 39% less. The division consists of a large swathe of areas from Maharashtra, Gujarat, Goa, Madhya Pradesh, Chhattisgarh, and Odisha.
Rainfall
IMD had earlier predicted normal rainfall activity during August
The deficiency in the northwest India division, which comprises northern Indian states, was 30%. The deficiency was 10% in the south peninsula whereas the east and northeast divisions received 2% more rainfall than the normal. The IMD had predicted that the rainfall activity was expected to be normal during August. It has now predicted above-normal precipitation in September.
Monsoon
Monsoon rainfall activities were largely subdued for three consecutive weeks
IMD said intra-seasonal variation in terms of the week-by-week rainfall variation over India shows that monsoon rainfall activities were largely subdued consecutively for three weeks -- for the week ending on August 11, August 18, and August 25, respectively. Notably, during this period, the weekly cumulative rainfall for the country as a whole was 35%, 36%, and 21%, respectively, below its LPA.
Further details
Negative IOD over Indian Ocean prevailed throughout August
The formation of fewer low pressure systems (PLS) and their lesser number of days compared to the climatology and absence of their longer westward movements during August 2021 contributed to the large deficient rainfall in central India and entire India, the IMD said. It said negative Indian Ocean Dipole (IOD) over the tropical Indian Ocean which is unfavorable for Indian monsoon prevailed throughout August.
Information
Negative IOD contributed to deficient rainfall in India in August
The IMD said that negative IOD also contributed to deficient rainfall over India in the month. Notably, a negative IOD is associated with the heating of waters of the Indian Ocean.