Final answer:
The weather characterized by spiral storms with winds up to 300 km/hour is known as a tornado, which is a violent windstorm that manifests as a rotating, funnel-shaped cloud.
Step-by-step explanation:
The type of weather characterized by spiral storms with winds of up to 300 km/hour is known as a tornado. Tornadoes are violent windstorms that appear as rotating, funnel-shaped clouds extending from thunderstorms down to the ground. Their winds can reach speeds as high as 500 km/h, particularly at the point where the funnel is narrowest.
Tornadoes are different from hurricanes, which are also spiral storm systems but are generally larger and form over warm ocean waters. Hurricanes have a defined wind speed category, where they are classified as hurricanes if they reach sustained winds of 74 miles per hour (approximately 119 km/h). These massive storm systems can achieve high wind speeds, often exceeding 200 km/h and can cause extensive damage.