Weather or Not
Day 4 - Tornadoes
By: harper mcdonald and piper stilwell
tornadoes - how they form
Tornadoes are rapidly rotating columns of air that form inside of massive thunderstorms called supercells that connect with the ground from a funnel cloud. They form because of hot, rising air that goes into the cloud, making it bigger. When there is a big enough amount of moisture at the bottom of the cloud, a mesocyclone is formed. Cool, dry, sinking air can start to wrap around the back of the mesocyclone, which forms a rear flank downdraft. This creates a large temperature difference between the air inside the mesocyclone and the air outside of it, building up a level of instability, allowing a tornado to thrive. This causes the lower part of the mesocyclone to become tighter. If this funnel moves down into the large, moist cloud base at the bottom of the parent storm, it sucks it in and turns it into a rotating wall of cloud, which forms a connection between the supercell and the earth.
tornadoes - where and when they occur
Tornadoes can form anywhere, but they form mostly in regions with flat, dry land, specifically North Texas, Oklahoma, Kansas, and Nebraska. The occurrence of tornadoes peaks around spring (March - May) because this is the time period with the most rain, creating a likelier chase of a supercell forming.
tornadoes - instruments and scales
A weather instrument that measures wind speed.
A device used to study tornadoes. They measure temperature, pressure, and humidity at ground level.
Classifies tornado wind speeds into 5 categories used to rate tornadoes:
EF-0 = winds that are 65-85 mph
EF-1 = winds that are 86-110 mph
EF-2 = winds that are 111-135 mph
EF-3 = winds that are 136-165 mph
EF-4 = winds that are 166-200 mph
EF-5 = winds that are over 200 mph