It looks like a funnel cloud in the photo Chicago photographer Nick Ulivieri snapped at 10:23 p.m. Sunday looking south from his balcony in University Village: a long, thin wisp curved toward Lake Michigan.
Ulivieri watched it for about three minutes, he said, describing it as “quite calm, and not particularly menacing.”
“What in the world is this cloud formation — A #Snownado?” he tweeted, along with his photo.
It’s possible it was a rare winter waterspout, the National Weather Service in Romeoville said Monday. Other possibilities Ulivieri has gotten in response to his tweet include a cold-air funnel or a phenomenon called a “steam devil,” he said.
The National Weather Service hasn’t had a lot of time to investigate the photo since it first became aware of it last night, meteorologist Matt Friedlein admitted.
It may have been steam rising from the lake, Friedlein said. The meteorologist has seen a lot of photos of steam rising through cracks in the ice just off the lakeshore, he said.
Or it may have been a winter waterspout, he said.
“It’s not very common in January at all” to see a waterspout, he said, both because there are fewer people on the water to spot them and because of the meteorology.
But, Friedlein said, “Last evening, there were some elements in place that could have helped a brief circulation to develop. It’s tough to say for sure.”
Waterspouts are most common on Lake Michigan in September and October, when the water still is very warm and the air, cooling, according to the meteorologist. That can create “instability,” he said, causing funnels or actual waterspouts to form.
The differences in temperature between the water and air generally are not as “sharp” in winter, he said. But the cold front that moved into the Chicago area this weekend “is very substantial,” he added.
The Canada-based International Centre For Waterspout Research, which picked up Ulivieri’s photo on Facebook, has still another explanation. It’s sure what the photographer saw was not a waterspout, but a “steam devil.”
According to the ICWR Facebook page:
Steam devils form under similar conditions as winter waterspouts, however, winter waterspouts are attached to convective cloud. Steam devils have no parent cloud. Steam devils frequenty appear to be attached to cloud over the lake, however, the poor contrast over the water in the winter time makes winter waterspout confirmation difficult.