A tornado is a column of violently rotating winds extending down from a thunderstorm cloud and touching the surface of the earth.
The difference between a funnel cloud and a tornado is that even though a funnel cloud also is a column of violently rotating winds extending down form a thunderstorm cloud, it does not touch the surface of the earth.
An average of 18 tornadoes occur in Michigan each year. Since 1950, 239 people have been killed due to tornadoes. During this time, Michigan has experienced 782 tornadoes.
Most tornadoes occur during the months for June, July and August in the late afternoon and evening hours. However, tornadoes can occur anytime of the day or night in almost any month during the year.
The speed of a tornado generally have a speed of 30 miles per hour. However, some tornadoes have had speeds approaching 70 mph.
The average Michigan tornado is on the ground for less than 10 minutes and travels a distance of about 5 miles. However, they do not always follow the norm, and have been known to stay on the ground for more than an hour and travel more than 100 miles.
Tornado Characteristics
What to look for
Time of day during which tornadoes are most likely to occur is mid-afternoon, generally between 3 and 7 p.m., but they have occurred at all times of day.
Direction of Movement is usually from southwest to northeast. (Tornadoes associated with hurricanes may move from an easterly direction.)
Length of Path average 4 miles, but may reach 300 miles. A tornado traveled 293 miles across Illinois and Indiana on May 26, 1917, and lasted 7 hours and 20 minutes.
Width of Path averages about 300 to 400 yards but tornadoes have cut swatches a mile or more in width.
Speed of Travel averages from 25 to 40 miles per hour, but speeds ranging from stationary to 68 miles per hour have been reported.
The Cloud directly associated with a tornado is a dark, heavy cumulonimbus (the familiar thunderstorm cloud) from which a whirling funnel-shaped pendant extends to the ground.
Precipitation associated with the tornado usually occurs first as rain just preceding the storm, frequently with hail, and as a heavy downpour immediately to the left of the tornado's path.
Sound occurring during a tornado has been described as a roaring, rushing noise, closely approximating that made by a train speeding through a tunnel or over a trestle, or the roar of many airplanes.