a tropical storm like the one named polo becomes a hurricane once its sustained winds reach at least 74 miles per hour. this classification change happens when the weather system organises into a closed circular pattern with a distinct center or eye, indicating the storm has gained significant thermal energy from warm ocean waters. How Meteorologists Classify Tropical Storms Photo: abc7.com on Google The transition from a tropical storm to a hurricane depends entirely on wind speed and internal structure. Meteorologists use the Saffir-Simpson Hurricane Wind Scale to categorise these events, which helps emergency services plan for potential damage. A system is only upgraded when it meets the following criteria: Closed Circulation: The clouds and winds must form a complete circle around a central point. Sustained Wind Speed: The system must maintain speeds of 74 mph or higher for at least one minute. Central Pressure: The air pressure at the center of the storm must drop sign...