GRAND RAPIDS, Mich. (WOOD) — Humidity hovering over the surface of Lake Michigan helped to form a spectacularly skinny roll cloud Monday afternoon over Ottawa County.
Roll clouds are rare, usually forming off the outflow from a thunderstorm or downpour. A gust of cooler wind can sometimes be felt as the skinny, tube-like feature rolls through.
According to the National Oceanic and Atmospheric Administration National Weather Service glossary, a roll cloud is “a low, horizontal tube-shaped arcus cloud associated with a thunderstorm gust front.” A gust front caused the one that formed just offshore from Ottawa County Monday.
The animation below shows the roll cloud began just south of Muskegon around 2:45 p.m. before tracking southeast into Ottawa County. At its peak length, it measured 16 miles long and only about a mile wide…