Tornadoes are rapidly rotating winds blowing around a small area of extreme low pressure that develops within a severe thunderstorm. Often visible as a funnel-shaped cloud, tornadoes can develop with little or no warning. Doppler radar and other advanced technology now give advance warning of many tornadoes. This weak tornado occurred in southeast Colorado. Across the dry High Plains just east of the Rocky Mountains, a tornado's funnel cloud may appear translucent or hollow in spots, although the winds may still be quite strong. Tornadoes in this region can gather large amounts of dust, and they may be more clearly visible than the rain-wrapped tornadoes that often occur farther to the east.
