Locally dense fog is affecting parts of southeast Iowa and western Illinois early Thursday morning, with some areas seeing visibility drop to a quarter-mile or less.
The fog is expected to be most common in river valleys, low-lying areas and locations that received rainfall Wednesday. Motorists traveling during the morning commute should be prepared for sudden changes in visibility, particularly when moving through low-lying areas.
The affected Iowa counties include Jackson, Clinton, Muscatine, Scott, Keokuk, Washington, Louisa, Jefferson, Henry, Des Moines, Van Buren and Lee counties.
In Illinois, the affected counties include Jo Daviess, Stephenson, Carroll, Whiteside, Rock Island, Henry, Bureau, Putnam, Mercer, Henderson, Warren, Hancock, McDonough, Scotland and Clark counties.
Cities included in the affected area are Maquoketa, Clinton, Muscatine, Davenport, Bettendorf, Sigourney, Washington, Wapello, Fairfield, Mount Pleasant, Burlington, Keosauqua, Fort Madison, Galena, Freeport, Mount Carroll, Sterling, Moline, Rock Island, Geneseo, Princeton, Hennepin, Aledo, Oquawka, Monmouth, Carthage, Macomb, Memphis and Kahoka.
Drivers who encounter dense fog are encouraged to slow down, leave extra distance between vehicles and use low-beam headlights. Visibility can change quickly over short distances.
The National Weather Service says conditions should gradually improve after 8 a.m. Thursday.
Source: National Weather Service, Des Moines office.
