Tornadoes start as a funnel cloud, becoming a tornado when they reach the ground.
A tornado that does not touch the ground is a funnel cloud.
No particular sky color necessarily indicates tornado activity. It is commonly state that a greenish sky indicates a tornado, but it doesn't need to be gray for a tornado to occur, nor does a green sky necessarily mean there is a tornado, just a severe thunderstorm. In a tornadic storm the clouds may appear green, gray, yellow, or black.
The Tuscaloosa-Birmingham tornado of 2011 was on the ground for about 90 minutes.
Tornadoes form in the sky within severe thunderstorms. They develop when warm, moist air rises rapidly and interacts with cooler, drier air at higher altitudes, creating a rotating column of air. Once this rotating column descends and touches the ground, it becomes a tornado.
Before a tornado hits the ground, a rotating column of air forms in the storm cloud known as a funnel cloud. This funnel cloud extends towards the ground, and once it makes contact, the tornado is then officially considered to have touched down.
The "fire tornado" forms from the fire; it doesn't really matter how the fire starts. Also, a "fire tornado" is more properly called a fire whirl as it technically isn't a tornado.
Tornadoes start as a funnel cloud, becoming a tornado when they reach the ground.
A tornado that does not touch the ground is a funnel cloud.
The National Weather Service issues a tornado warning when a tornado has been spotted on the ground or indicated by weather radar in your area. This is to alert residents to take immediate shelter and protect themselves from the approaching tornado.
A tornado that doesn't touch the ground isn't a tornado; it is a funnel cloud. However if the funnel is pulling debris off the ground or making some other type of contact with the ground it is a tornado.
A funnel cloud that touches the ground is commonly known as a tornado.
No particular sky color necessarily indicates tornado activity. It is commonly state that a greenish sky indicates a tornado, but it doesn't need to be gray for a tornado to occur, nor does a green sky necessarily mean there is a tornado, just a severe thunderstorm. In a tornadic storm the clouds may appear green, gray, yellow, or black.
A tornado often appears dark were it is touching the ground be cause the powerful winds of the tornado lift dirt from the ground.
tornado
The intensity of a tornado is rated based on damage done on the ground.
The Tuscaloosa-Birmingham tornado of 2011 was on the ground for about 90 minutes.