A funnel cloud or (rarely) a small, relatively weak tornado that can develop from a small shower or thunderstorm when the air aloft is unusually cold (hence the name). They are much less violent than other types of tornadoes.
COLD-AIR FUNNEL
Meaning of COLD-AIR FUNNEL in English
A comprehensive English glossary of weather. Полный английский глоссарий погоды. 2012