A cold air funnel occurs when the air at the surface is warm but the air aloft is especially cold.
A cold air funnel forms well above the earth’s surface. They often have weak circulation and rarely touch the ground but on the off chance they do they can become an EF-0 tornado.
They form when the wind from the surface to the middle of the troposphere flow in different directions. This may lead to some weak circulation. If there is enough condensation rising from the warm moist surface, a condensation funnel may form at the base of the cloud.