A supercell thunderstorm that crossed eastern Colorado on the evening of 6 June 1990 produced several tornadoes, one of which devastated the town of Limon. This image shows the pre-tornadic phase of the Limon storm at 1902 Mountain Daylight Time. 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. (Full sequence: DI00523-DI00553)
