What are some signs that a tornado is developing?

Question

What are some signs that a tornado is developing?

Answer 1

Wall cloud, funnel, spiral updraft.. low pressure system.

a cow spinning high above you??

Answer 2

*   Strong, persistent rotation in the cloud base

    * Whirling dust or debris on the ground under a cloud base—this may indicate a tornado funnel that is still inside the cloud

    * Hail or heavy rain followed by either dead calm or a fast, intense wind shift. Many tornadoes are wrapped in heavy precipitation and can’t be seen

    * Loud, continuous roar or rumble, which doesn’t fade in a few seconds like thunder. A tornado also may sound like a waterfall, trains, and jets

    * Night- Small, bright, blue-green to white flashes at ground level near a thunderstorm, opposed to lightning flashes or strikes. These mean power lines are being snapped by very strong wind, which may be a tornado

    * The sky may be a greenish black color.

    * Clouds moving by very rapidly, which indicates strong winds

    * Debris falling from the sky

    * A funnel cloud that hasn’t touched the ground yet is a huge sign of a tornado.

Answer 3

The old clichés apply... green sky, dust or debris cloud and maybe a deep, low sound that some might describe as a freight train.

Actually, look for a low or "rotating" cloud... if there's a set cloud beneath the base of the storm, it's a "wall" cloud, and if there is no "wall" cloud, but an actual funnel, then that's a big sign that a tornado could be coming.