Cyclone Shakti alert in Maharashtra

Cyclone Shakti alert in Maharashtra

Why in News?

The India Meteorological Department (IMD) has warned that Cyclone ‘Shakti’, the first storm of the season over the Arabian Sea, may bring heavy rainfall and strong winds to Maharashtra’s coastal areas, including Mumbai, in the coming days.

Highlights of Cyclone ‘Shakti’ 2025

• • Formation: Cyclone Shakti is the first significant cyclonic storm of the 2025 season over the Arabian Sea. The storm began forming in late September 2025 as a low-pressure system. By early October, it intensified into a cyclonic storm due to favorable ocean temperatures and atmospheric conditions. 

• Duration: The IMD has issued warnings from October 3 to October 7, 2025, for parts of Maharashtra. Strong winds and heavy rainfall are expected during this period. The storm’s effects will peak along the northern coastal districts between October 3 and October 5, with a gradual decrease after October 6.

• Wind Speed: The IMD has classified this cyclone as a moderate to high-intensity storm. Cyclone Shakti is likely to bring strong winds of 45-55 kmph, with gusts reaching up to 65 kmph. The wind speed may vary as the cyclone moves closer to the coast.

• Sea Condition: The Arabian Sea is expected to remain very rough until October 5, 2025. High waves and turbulent water conditions may disrupt fishing activities and sea travel.

• Districts to be Affected: Cyclone Shakti is expected to bring heavy to very heavy rains to both coastal and interior Maharashtra.

• The cyclone warning has been issued for six districts: Mumbai, Thane, Raigad, Ratnagiri, Palghar, and Sindhudurg. Coastal and low-lying areas are particularly at risk. 

• Interior parts of Maharashtra, including East Vidarbha and Marathwada, may also receive heavy to very heavy rainfall. 

• Flooding is possible in low-lying regions of North Konkan due to continuous rainfall and water accumulation.

• Advisories: The Maharashtra government has instructed district administrations to activate disaster management systems. Coastal and low-lying residents should prepare evacuation plans. Citizens are advised to stay indoors, avoid sea travel, and follow official updates. Emergency services and local authorities are on alert to manage potential disruptions.

What is a Cyclone?

• A cyclone is a large system of winds that rotates around a low-pressure area. It is a natural phenomenon that forms over oceans and seas when warm, moist air rises and creates strong winds. 
• Cyclones are often accompanied by heavy rainfall and storm surges. They are one of the most powerful and destructive weather systems in the world.
• The word “cyclone” comes from the Greek word kyklon, which means “moving in a circle” or “whirlpool.” 
• Cyclones are classified based on their intensity and wind speed. They are classified as extratropical cyclones (Temperate cyclones) and tropical cyclones.
• Tropical cyclones usually occur in the Indian Ocean, Pacific Ocean, and Atlantic Ocean. 
• Cyclones are most frequent in the North Indian Ocean, including the Bay of Bengal and Arabian Sea. 
• According to the IMD data from 2020 to 2025, India experiences an average of five to six cyclones each year, with one or two severe storms that can cause extensive damage.
• In 1999, the Orissa super cyclone in India killed over 10,000 people and destroyed homes, crops, and infrastructure. 
• Similarly, Cyclone Nargis in 2008 caused catastrophic damage in Myanmar, affecting millions and killing nearly 140,000 people.
• Cyclones weaken when they move over cooler waters or land. The system loses its heat and moisture supply, causing wind speeds and rainfall to decrease. 

Classification of Cyclones Based on Wind Speed 

The India Meteorological Department (IMD) uses specific wind speed ranges to categorize cyclones in the North Indian Ocean. These classifications help authorities plan safety measures in coastal regions.

• A Depression is the weakest type of cyclone. It forms when wind speeds are between 31 to 49 kmph. Depressions generally bring moderate rainfall and light winds. They rarely cause severe damage but can disrupt local traffic and small agricultural areas. 
• A Deep Depression has wind speeds between 50 and 61 kmph. This stage brings heavier rainfall and stronger winds than a regular depression. Flooding may occur in low-lying areas. 
• A Cyclonic Storm occurs when wind speeds reach 62 to 88 kmph. These storms can uproot trees, damage weak structures, and disrupt transport. The IMD issued warnings for cyclonic storms in 2020 and 2021 in Maharashtra and Odisha. 
• A Severe Cyclonic Storm has winds between 89 and 117 kmph. These storms can cause significant damage to houses, power lines, and crops. The 1996 Odisha Cyclone was classified as a severe cyclonic storm, causing heavy rainfall.
• A Very Severe Cyclonic Storm has wind speeds between 118 and 166 kmph. These storms can destroy weak buildings, uproot trees, and flood coastal areas. The 2013 Phailin Cyclone in Odisha was a very severe cyclonic storm. 
• An Extremely Severe Cyclonic Storm occurs when wind speeds range from 167 to 221 kmph. These storms can devastate infrastructure, uproot large trees, and cause storm surges in coastal regions. The 1999 Odisha Super Cyclone was an extremely severe cyclonic storm. 
• A Super Cyclonic Storm is the most powerful category. Wind speeds exceed 222 kmph. These storms can destroy entire towns, cause massive flooding, and displace large populations. Super cyclones are rare but have severe consequences.

Causes of Cyclones

• Warm Ocean Water: Cyclones form over warm ocean waters, typically when the surface temperature rises above 26.5°C. The heat and moisture from the ocean feed the cyclone, allowing it to strengthen as it moves.

• Low-Pressure Area: A low-pressure area is essential for cyclone formation. When air near the ocean surface rises due to heating, it creates a pressure drop. Surrounding air rushes in to fill the space, creating strong winds. 

• Moist Air: Cyclones require humid air to develop. Warm, moist air rises from the ocean, and as it rises, it cools and condenses. This condensation releases latent heat, which fuels the cyclone and strengthens the wind system.

• Coriolis Effect: The Coriolis effect caused by Earth’s rotation makes the cyclone spin. Cyclones rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

• Wind Patterns: Certain wind patterns help cyclones form and move. For example, winds that converge near the equator and move toward the poles create rotation. Meteorologists observed that shifts in monsoon winds in India influenced cyclone paths.

• Ocean Currents: Ocean currents also affect cyclone formation. Warm currents provide extra energy, while cold currents can weaken the storm. Cyclones forming in the Bay of Bengal are usually stronger than those in the Arabian Sea due to warmer currents.

Process of Formation of Cyclones

• Warm Ocean Water: Cyclones begin over warm ocean waters with temperatures above 26.5°C. The heat from the water causes evaporation, adding moisture to the air above the sea. This warm, moist air provides the energy needed to fuel the developing storm.

• Rising Warm Air: As the warm, moist air rises from the ocean surface, it creates a low-pressure area. When this air cools, the water vapor condenses into clouds. The condensation releases latent heat, which warms the surrounding air and makes it rise further, strengthening the low-pressure system.

• Cyclonic Rotation: The Earth’s rotation causes the rising air to spiral, a phenomenon called the Coriolis effect. In the Northern Hemisphere, the air rotates counterclockwise, while in the Southern Hemisphere, it rotates clockwise. This spiral motion forms the basic structure of a cyclonic system.

• Disturbance: The initial system of rising air may appear as a small atmospheric disturbance. Meteorologists classify this as a tropical depression. As the system strengthens, the low-pressure area deepens, and the wind speeds start increasing.

• Storm Formation: When wind speeds reach 63-118 km/h, the system is classified as a tropical storm. The storm becomes organized, with distinct spiral cloud bands forming around the center.

• Cyclone Formation: Once the wind speeds exceed 119 km/h, the system is called a tropical cyclone. In the Atlantic and Eastern Pacific, it is called a hurricane, and in the Western Pacific, a typhoon. The cyclone develops a clear eye, surrounded by the strongest winds in the eyewall.

Prediction and Monitoring of Cyclones

• Meteorologists use weather forecasting to predict cyclones before they form. They analyze data from satellites, weather stations, and ocean buoys to track wind, temperature, and pressure. 
• The India Meteorological Department (IMD) has been issuing cyclone forecasts since 1875, and modern forecasting has improved accuracy over the years.
• Satellite monitoring provides real-time images of cyclones. Satellites detect cloud formation, wind patterns, and storm intensity. India uses satellites like INSAT-3D and INSAT-3DR, launched in 2013 and 2016, to monitor the Indian Ocean region.
• Early warning systems alert communities before a cyclone hits. The IMD issues warnings using color-coded signals and public advisories. Since 2010, India has improved its warning system with text messages, TV alerts, and social media updates.
• Cyclones are given official names to simplify communication. The process is coordinated by the World Meteorological Organization (WMO) and its regional bodies, which follow strict guidelines. India follows a list of names contributed by eight countries bordering the Indian Ocean.
• IMD uses numerical weather prediction models to simulate cyclone behavior. These models predict the path, intensity, and rainfall of storms. Doppler radar systems measure wind speed and rainfall in real-time. India has over 35 Doppler radars across coastal states as of 2023. 
• The IMD and state governments conduct public awareness programs to educate people about cyclones. Communities learn evacuation routes, safety measures, and emergency contacts.