Stagnant, chilly air breeds dense, freezing fog in southeast Michigan

Detroit — Stagnant air over southeast Michigan had led to patchy dense fog in the region, that has visibility ranging from a quarter-mile to two miles as morning rush hour begins Tuesday.

In a special weather statement, the National Weather Service urged motorists to "use caution" when driving this morning. As the statement says: "With temperatures below freezing, moisture may tend to freeze on some area roadways. Bridges and overpasses will be most susceptible to slick spots through the morning commute."

Visibility is at two miles at Detroit Metro Airport in Romulus, and 1.5 miles in Ann Arbor, said Sara Pampreen, a National Weather Service meteorologist. In Howell and Jackson, visibility is down to a quarter-mile.

But in White Lake, where the weather service's Detroit office is located, there's little fog to speak of. Two miles of visibility is well below the six or so "statute miles" it takes for the fog to make weather reports, Pampreen said, and the fog Tuesday morning is considered "dense."

Once the sun emerges, the fog will dissipate.

Highs Tuesday are expected to reach the low-40s.