Strong warm updrafts carrying large amounts of moisture interacting with fast-moving cool, dry winds above cause tornadoes when the two air currents begin to swirl around each other and reorient toward the ground. The moist updraft is always of a type that forms large storm clouds as it ascends and the water vapor in it condenses.Know More
The interaction between the two air currents must be extremely energetic to form a tornado. It requires the winds the warm updrafts interact with to be moving 150 miles per hour or more. Initially, the swirling air from the interaction of the two air currents is known as a mesocyclone and is oriented horizontally rather than vertically. The column of air formed by this phenomenon grows narrower as the wind speed inside it increases. If the wind shear causes the air column to reorient to a vertical position, it can stretch out to meet the land and form a tornado.
Tornadoes always begin in powerful thunderstorms. The most likely type of storm to produce a tornado is the most powerful type, known as a supercell. The cumulus clouds that form these storms are usually created by air that is at least 75 degrees Fahrenheit in temperature. Warm air is lighter than cool air, so the air is inherently unstable when there is cold air above and warm air below.Learn more about Storms
Tornadoes are narrow, circulating columns of air that originate from a supercell thunderstorm, from the cloud to the ground, and constantly become darker as they pick up dirt and debris from the ground. Tornadoes move at an average speed of 35 mph and have an average span of about 5 miles.Full Answer >
According to the National Oceanographic and Atmospheric Administration, tornadoes form when warm air creates a rotating updraft in a powerful thunderstorm. When winds blow in sharply different directions or at different speeds in these storms, they can set up a rotation that feeds on itself, creating a condition called a mesocyclone. When this construct rotates and touches the ground, it becomes a tornado.Full Answer >
Tornadoes form when unstable air in a thunderstorm creates a horizontal rotation in the clouds and strong downdrafts draw that vortex down to the ground. Overlapping fronts can trigger the wind shear necessary to initiate a tornado's rotation, which is why meteorologists issue watches whenever severe thunderstorms threaten. Tornadoes can form with very little notice and are particularly unpredictable and dangerous weather events.Full Answer >
Tornadoes have wind gusts of 65 miles per hour to over 200 miles per hour. Tornadoes are classified by strength and estimated wind speed, according to the Enhanced Fujita Scale, which assigns a rating of between EF0 and EF5.Full Answer >