Cold Air Funnel
(Section 3.2.1.5.4)Definition: Cold-air funnel: 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.
Cold-air funnels typically do not reach the ground (funnel cloud), but when they do reach the ground as tornadoes, they are much less violent than the other types.