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whereas winds higher up at 5,000 feet altitude might be blowing east at 25 mph (40 kph). This creates a shear that begins to create an invisible tube of air that begins to rotate horizontally. The updraft carries the warm air upward, which promotes the formation of a strong thunderstorm. Once the updraft is rotating and warm, moist air is flowing up into the tube, a tornado can form. The updraft becomes more intense, and as it strengthens, a rotating column of air called a mesocyclone forms when wind shear causes the updraft to horizontally rotate. The rising air within the storm tilts the rotating air from horizontal to vertical. At this point, the storm continues to develop and cool air descends downward from the core of the storm. This is called a downdraft, and it wraps around the mesocyclone, strengthening the rotating air. The downdraft helps give the tornado more structure. A specific type of downdraft called a rear flank downdraft (RFD) forms on the back side of the storm and also wraps around the mesocyclone. The updraft and mesocyclone become strong enough and the atmospheric conditions help form what is known as a wall cloud beneath the storm. A wall cloud is a very low, flat base of the storm that forms before a tornado develops. The tornado funnel will then develop within the wall cloud. The air within the funnel continues to rotate, and a drop in air pressure occurs. Moisture (water droplets) inside the funnel results in condensation and as a result, a visible funnel appears. The funnel extends downward from the base wall cloud. If you see dust and debris beneath the condensation funnel, that indicates the presence of a tornado. When the funnel comes into contact with the ground, a tornado is born.

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What Makes a Tornado