One-third of India in severe rain deficit as monsoon enters last leg, Pg14

Key Highlights:

• Nearly 35% of India's geographical area is experiencing a significant rain deficit as the Southwest Monsoon approaches its final phase.
• The country-wide rainfall since June 1 is 554.2mm, which is 13% short of expected levels for this period, according to the India Meteorological Department (IMD).
• 412 districts across 14 states and Union Territories, primarily in the south peninsula, northeast, and parts of eastern and northwest India, have recorded a deficit.
• States like Goa, Kerala, Punjab, and Rajasthan are facing deficits ranging from 22% to 33% despite their varied normal rainfall patterns.

Detailed Insights:

• The cumulative rainfall departure from normal has consistently remained negative throughout the current monsoon season.
• Rainfall activity in the central region, specifically between Odisha and Gujarat, has been prominent due to recurrent low pressure systems developing in the Bay of Bengal and moving inland.
• The spatial distribution of rainfall has been highly skewed, with significant disparities even at the district level.
• Some states, like Assam, have experienced severe floods in certain areas while simultaneously reporting rain deficits in 19 out of 35 districts.
• Meghalaya shows a substantial overall deficit, with only one district receiving excess rainfall, while others are in deficit or 'large' deficit categories (rainfall -60 to -99 per cent below normal).
• Andhra Pradesh, including regions of Yanam and Rayalaseema, is entirely in a rain deficit, contrasting with Odisha where all 30 districts have received normal or above-normal rainfall.
• The IMD forecasts continued monsoon activity over west Uttar Pradesh, west Madhya Pradesh, and Chhattisgarh until August 29, driven by a prevailing low pressure system over Jharkhand.

Key Concepts Involved:

• Southwest Monsoon: Seasonal winds bringing the majority of India's annual rainfall from June to September, crucial for the country's agriculture and economy.
• India Meteorological Department (IMD): The principal government agency in India responsible for meteorological observations, weather forecasting, and seismology, operating under the Ministry of Earth Sciences.
• Low Pressure Systems: Regions where atmospheric pressure is lower than surrounding areas, typically associated with rising air, cloud formation, and precipitation.
• Rainfall Deficit: A situation where the actual cumulative rainfall received over a period is less than the Long Period Average (LPA) for that region and time.