What are upper-level troughs and ridges?

A tornado is a rotating funnel-shaped cloud that drops out of a storm cloud to the ground. Whirling winds range from 75 to 300 miles an hour. What is a tornado and what causes it? A tornado or twister is a narrow, violently rotating column of air. It is usually attached to the base of a thunderstorm, ... Quick Tornado Facts · Tornadoes cause an average of 70 fatalities and 1,500 injuries in the U.S. each year. · The strongest tornadoes have rotating winds of ... The sky may be sunny when you first hear a severe thunderstorm or tornado watch. After you learn of a watch, check weather information frequently: While watches ... Tornadoes. A tornado is a violently rotating column of air that extends from a thunderstorm and comes into contact with the ground, according to the National ... The key atmospheric ingredients that lead to tornado potential are instability - warm moist air near the ground, with cooler dry air aloft and wind shear - a ... Aug 4, 2020 ... A tornado watch is typically issued hours in advance by NOAA's Storm Prediction Center (SPC). It means that conditions are ideal for a tornado ... Tornadoes are the world's most violent atmospheric storms. They are narrow, violently rotating columns of air extending from the base of a thunderstorm to the ... Nov 7, 2018 ... The spot of higher correlation coefficient values correlating with rotation is sometimes called a tornado debris signature, which was present ... Watches are issued by the Storm Prediction Center for counties where tornadoes may occur. The watch area is typically large, covering numerous counties or even ...