A Triplicate Facebook post from Brian Thibault shows what appears to be a small funnel cloud on Sunday near the Del Norte County Regional Airport on Dale Rupert Road in Crescent City.
National Weather Service Meteorologist Matthew Kidwell could not confirm that there was an actual funnel cloud in the area.
"It could be a weak, cold air funnel," Kidwell said.
Science Office Mel Nordquist, at the Eureka National Weather Service Office, said the cold air funnel clouds are formed through interaction of gusting winds.
"The gusting winds cause small areas of rotation and that rotation can be stretched up into the vertical and that forms into a cold air funnel cloud," Nordquist said. "These normally occur behind fronts, with cold air behind the front is unstable rising and falling."
Nordquist said typically, the cold air funnel clouds won't reach the ground.
"And if they do reach the ground, they normally don't do any damage at all," he said.
The National Weather Service has issued a Hazardous Weather Outlook for Coastal Del Norte-Del Norte Interior, Northern Humboldt Coast, Southwestern Humboldt, Northern Humboldt Interior, Southern Humboldt Interior, Northern Trinity, Southern Trinity, Mendocino Coast, Northwestern Mendocino Interior- Northeastern Mendocino Interior, Southwestern Mendocino Interior, and Southeastern Mendocino Interior counties in effect Wednesday through Monday.
A storm system will yield periods of heavy rain and strong winds Thursday night into Friday. Snow levels will generally remain above 5,000 feet, which will preclude significant winter weather impacts, with the possible exception of Scott Mountain Summit on Highway 3.
Follow this developing weather issue here online at thetriplicate.com.