TITLE: tornado: Funnel clouds
SECTION: Funnel clouds
A tornado is often made visible by a distinctive funnel-shaped cloud. Commonly called the condensation funnel, the funnel cloud is a tapered column of water droplets that extends downward from the base of the parent cloud. It is commonly mixed with and perhaps enveloped by dust and debris lifted from the surface. The funnel cloud may be present but not visible due to heavy rain. Over a...
TITLE: tornado: The tornado core and the condensation funnel
SECTION: The tornado core and the condensation funnel
With air pressure in the vortex core thus reduced in comparison to the pressure outside the core at the same elevation, a condensation funnel forms. This occurs because, at lower atmospheric pressure, air flowing upward in the core cools more quickly with increasing height than air rising at higher pressure just outside the core. Assuming that inflowing air has the same amount of moisture...