Monsoon deficiency shrinks to 4% from 9% on good Sept rains
The overall deficiency in monsoon rains has reduced to 4% till Sunday, down from 9% recorded at the end of August, due to a revival of weather systems that triggered moderate to heavy showers this month, scientists have said.
According to IMD, monsoon is now in the “normal” category (in the range of 96% and 104% of long period average) this year, and more showers are expected in the remaining days of the month.
Monthly monsoon rains have been particularly skewed this year – there was 9.6% excess rain at the end of June, then a 6.8% deficiency in July, which rose to 24% deficiency in August, until September turned it around to 28.7% excess rain till Sunday.
Data shows that September has been the most active monsoon month this year – instead of July and August, which normally witness a major chunk of rainfall.
The maximum number of districts which faced dry/arid conditions were in Gujarat, but are now in wet condition following widespread and heavy rain this month.
Almost all of northeast India and J&K and Himachal Pradesh continue to remain dry.
“There is a sudden revival in the dry states which is good because there were drought conditions in Gujarat and parts of Odisha. This will help in groundwater recharge ahead of winter crops,” Pulak Guhathakurta, head of climate research division at IMD Pune, said.
NEW DELHI: There has been a 4% deficiency in monsoon rains till Sunday in comparison to the 9% deficiency at the end of August, even as more showers are expected till the end of this month, India Meteorological Department (IMD)’s extended range forecast revealed.
Currently, the monsoon is in the “normal” category which is 104% to 96% of the long period average. Monsoon rains have been extremely skewed this year with 9.6% excess at the end of June, 6.8% deficiency in July, 24% deficiency in August and 28.7% excess in September till Sunday. Instead of July and August, September has been the most active monsoon month this year. According to the north Indian Ocean’s extended range outlook, a cyclonic circulation is likely to form over east-central Bay of Bengal around September 23-24 with a near similar pattern of movement as the one that is presently over Madhya Pradesh. The cyclonic circulation likely to form over Bay of Bengal is expected to bring widespread rains over central and parts of northwest India.
“The monsoon trough is very active right from the northern parts of the country to the western Pacific. The favourable position of Madden Julian Oscillation (MJO) is supporting convective activity. Though a cyclonic circulation is weaker in intensity than a low pressure system, it is likely to bring rainfall over many parts of the country till the end of the month,” Sunitha Devi, in charge of cyclones at IMD, said.
The MJO is an eastward moving disturbance of clouds, rainfall, winds and pressure that traverses the planet in the tropics and returns to its initial starting point in 30 to 60 days on average, according to the National Oceanic and Atmospheric Administration. Its location and amplitude strongly modulates the intensity of tropical convection and features like low pressure systems over the north Indian Ocean.
In September, the monsoon season changed so abruptly that districts which were “severely” and “extremely” dry as per the IMD’s drought monitoring from June to August, have now turned “mildly dry” as per the standard precipitation index (SPI).
The SPI is an index used to monitor drought -- it is negative for drought and positive for wet conditions.
For the period June to August, 129 districts were found to be in moderately/severely/extremely dry conditions or moderately/ severely arid conditions, and 43 districts under dry conditions in all the three drought indices (rainfall, aridity and SPI monitored by IMD). These 43 districts remained under severe waterstressed conditions till the end of August.
The maximum number of districts which faced dry/arid conditions were in Gujarat, but are now in wet condition following widespread and heavy rain this month. Almost all of northeast India and Jammu and Kashmir and Himachal Pradesh continue to remain dry.
“There is a sudden revival in the dry states which is good because there were drought conditions in Gujarat and parts of Odisha. This will help in groundwater recharge ahead of winter crops,” Pulak Guhathakurta, head of climate research division at IMD Pune, said.
“Power of the #monsoon! Rainfall deficit at the end of August (left) turning to rainfall surplus in mid-September (16th, right).