A hurricane or typhoon or a cyclone is a large cyclonic weather system with continuing winds of at least 33 m/s (64 kt, 74 mph, or 118 km/h). A tropical cyclone with this wind speed usually develops an eye, which is an area of calm conditions at the center of its circulation. The eye is often seen from space as a small, round, cloud-free spot. Around the eye is the eye wall, an area where the strongest thunderstorms and winds spin around the storm's center. The fastest possible continuing wind speed found in tropical cyclones is thought to be around 85 m/s (165 kt, 190 mph, 305 km/h).