How does a tornado compare to a hurricane?

Answer 1

Both tornadoes and hurricanes are violent weather events with powerful winds that rotate in a cyclonic directions, that is counterclockwise in the northern hemisphere and clockwise in the southern (with the exception of a very small percentage of tornadoes). Both have low barometric pressure at their centers.

Despite these similarities, tornadoes and hurricanes are very different.

A hurricane is a large-scale storm known generically as a tropical cyclone. It is its own, self sustaining weather system and is typically a few hundred miles across. As the generic term implies, hurricanes form primarily in the tropics. They develop over warm ocean water and gain their spin from the Coriolis effect, a consequence of Earth's spin. As large scale storm systems, hurricanes take several days to form, and most changes to hurricanes happen over the course of hours or days. Some hurricanes last for weeks. The primary threat from hurricanes is flooding from torrential rain, and the wind pushing seawater onto land in what is called a storm surge. The wind itself is a danger as well. Sometimes, severe thunderstorms develop in the outer rain bands of hurricanes, sometimes resulting in tornadoes. To qualify as a hurricane, a tropical cyclone must have sustained winds of at least 74 mph. Sustained winds near 200 mph have been recorded.

By contrast, a tornado is a small scale event dependent on a parent thunderstorm. Most tornadoes are no more than a few hundred feet wide, though some can exceed a mile, or on rare occasions 2 miles in diameter. Tornadoes are not as limited as hurricanes in geographic distribution. They can occur almost anywhere, but they typically form on land in temperate or subtropical regions. Unlike hurricanes, tornadoes are too small to be significantly influenced by the Coriolis effect, at least not directly. In stead they gain their spin from vertical wind shear, or differences in wind speed and direction with altitude, interacting with thunderstorms. As small scale events tornadoes form in a matter of minutes, and usually don't last more than a few minutes. Some last mere seconds. On rare occasions, however a tornado may last for a few hours. The primary cause of damage in tornadoes is their wind, which can severely damage or destroy buildings, and topple trees. The wind may also carry debris, which cause additional damage and is responsible for most tornado deaths. There is no official minimum wind speed, though the EF0 wind range begins at 65 mph, tornadoes have been rated with winds estimated as low as 55 mph. Winds to over 300 mph have been recorded.