In the second half of the south-west monsoon season, more than 106% of the long-term average from August to September is expected to have a normal rainfall, the India Meteorological Department announced in an forecast on Thursday.
Most parts of India are likely to receive up-to-normal rainfall during this period, except for the northeastern and adjacent eastern regions, some isolated regions of central India and southwest parts of the peninsular India, where below-normal rainfall is expected.
IMD Director General M Mohapatra said, “From the last five years to 2021 to 2025, rainfall has been normal in East and Northeast India. In fact, we can see a fall in rainfall in the region for the last few decades.”
The long-term average for the August-September period is 422.8 mm, based on historical data from 1971 to 2020.
For August, especially, nationwide rainfall is likely to remain within a normal range of 94% to 106% of long -term average. In this period, Central India is expected to experience normal rainfall in many parts of the Western Peninsular regions, Northeast India and some regions of eastern and northwest India.
In August, the temperature below normal in the temperature pattern will be seen below normal, except for the northeast India and parts of the northeast India and the northwest, east and southern peninsula, where the above temperature is likely.
Night temperatures are expected to be above normal in most areas, although parts of Northwest India may experience below the normal minimum temperature.
July proved an active month for monsoon activity, with 4.8% more rainfall during the month of the country. There is a lot of variation in regional performance, 12.2% more rainfall with Northwest India and 21.9% more rainfall in Central India. However, East and Northeast India faced a reduction of 26.4%, while South Peninsular India recorded a 2% decrease.
The monsoon activity of July was particularly acute, 193 meteorological stations recorded heavy rainfall over 20 cm, and 624 stations reported very heavy rainfall between 11.56 cm and 20.45 cm. This month also recorded the ninth highest night temperature, while East and Northeast India experienced their fourth most hot July since 1901.
Several factors contributed to the strong rainfall of July, including neutral ENSO conditions and the formation of six low pressure systems, which have intensified in four sediments-systems that continue to affect the current weather patterns in northern and central India.
The performance of cumulative monsoon from 1 June to July 31 shows 6.4% more rainfall at the national level, but regional inequalities persist. Northwest India has recorded 21.1% additional rainfall, while Central India shows 22.9% more. In contrast, East and Northeast India faces a 22% decrease, and South Peninsular India has a decrease of 2.3%. East and Northeast India’s rainfall was the lowest seventh since 1901 and the fourth lowest since 2001, related to a trend.
The forecast for August and September falls against the backdrop of the neutral L Nino-south oscillation positions prevalent on the equatorial Pacific region. The latest monsoon missions indicate the climate forecast system and other climate models that these neutral conditions will continue through the remaining monsoon period. Similarly, the current neutral Indian Ocean is expected to infection in weak negative conditions by the end of the monsoon season from bipolar conditions.
The incidence of El Nino usually suppress the rainfall by weakening the monsoon winds and by reducing moisture transport from the oceans. Conversely, the position of La Nina usually increases the monsoon activity that strengthens the pressure shield running the monsoon circulation. The state of neutral enso, as currently prevalent, provides a favorable environment for normal monsoon performance, allowing regional weather systems to work without mass interference from Pacific Ocean temperature discrepancies.
What could be important for weather monitoring, IMD announced monitoring of block-level rainfall covered 7,200 administrative blocks across the country. This represents ten times the increase in spatial resolution compared to existing systems and will increase data granularity for applications in agriculture, disaster management, water resources management and model verification.
“Earlier we used to provide district-level rainy data, but now we will also provide block-level rain monitoring,” Mohapatra explained. Increased monitoring capacity supports adequate increase in rain gauge, from 3,980 to 6,727 in 2015 to 6,727.
