A 'very severe' cyclonic storm, Arnab, made landfall on India's eastern coast early on October 28, bringing intense wind and rain. For millions in its path, the key to safety lies in technology, particularly satellite imagery.
The Storm's Path to Landfall
Cyclone Arnab formed over
the Bay of Bengal, rapidly intensifying from a cyclonic storm on October 26 to a 'very severe cyclonic storm' by October 27. Forecasters at the India Meteorological Department (IMD) used a constant stream of satellite data to watch its development. The storm tracked west-northwestward across the bay before making landfall along the Andhra Pradesh and Yanam coasts. The landfall process, which is when the storm's centre moves over land, began in the early hours of Wednesday, October 28, hitting the coast near Kakinada. At its peak, the cyclone packed sustained wind speeds of 125-135 kmph, with gusts reaching up to 150 kmph, causing significant disruption.
What Satellite Images Reveal
Satellite imagery is a crucial tool for tracking cyclones where direct observation is impossible. Weather satellites like India's INSAT-3DS provide continuous updates on a storm's location, structure, and intensity. Visible and infrared images allow meteorologists to analyse cloud patterns; dense, organised, and spiral-shaped cloud bands often indicate a more intense cyclone. For Cyclone Arnab, thermal infrared images showed massive clusters of bright white clouds, which signify very cold, high cloud tops associated with powerful thunderstorms. These images helped forecasters identify the storm's core and track its movement with high confidence, providing the basis for timely public warnings.
Identifying Heavy Precipitation Zones
One of the greatest threats from any cyclone is extreme rainfall, leading to widespread flooding and landslides. Satellite data is instrumental in identifying these heavy precipitation zones. The coldest cloud tops, detected by infrared sensors, often correspond to the most intense rainfall. Ahead of Arnab's landfall, satellite bulletins highlighted 'intense to very intense' convective cloud activity over north coastal Andhra Pradesh and southern Odisha. This data was tragically accurate. As the storm hit, extremely heavy rainfall was recorded in numerous locations, with some areas in the Anakapalli, Vizianagaram, and Visakhapatnam districts receiving over 200 mm of rain between October 27 and 28. Visakhapatnam alone recorded 217 mm. The IMD issued flash flood warnings for several coastal districts based on this forecast.
Impact and Response on the Ground
The impact of the heavy wind and rain was immediate. Reports emerged of uprooted trees, damaged roads, and disrupted power lines across coastal Andhra Pradesh. In Kakinada, police rescued four people stranded in floodwaters. Proactive measures, guided by the storm's predicted path, likely saved many lives. Authorities in Andhra Pradesh evacuated over 84,000 people to nearly 300 relief shelters. Neighbouring Odisha also closed schools in 16 districts as a precaution. The storm's impact rippled through the region's transport networks, with dozens of trains and at least 21 flights cancelled to ensure public safety. After landfall, the storm began to weaken as it moved inland but was still expected to bring heavy rain to several states, including Telangana, West Bengal, and Jharkhand.
