text: Satellites that participated in the THEMIS project first discovered evidence of these things occurring on the Sun.
full_question: Satellites that participated in the THEMIS project first discovered evidence of these things occurring on the Sun. These phenomena are often preceded by the appearance of a hook echo, and they can be created by systems known as supercells. Large varieties of these are known as their "wedge" form. The two nations that see the most of these phenomena now measure their power on an "enhanced" scale. Most of these things occur in a strip of land which includes the Great Plains and is known as their namesake "Alley." For 10 points, name these rotating funnel clouds that contact the ground and feature high wind speeds, whose strength is measured by the Fujita scale.
first_sentence: Satellites that participated in the THEMIS project first discovered evidence of these things occurring on the Sun.
raw_answer: tornadoes [or twisters; or cyclones]