A dense blob of ‘radiation fog’ has moved in over the Southeast, causing dangerous travel conditions for up to five million people.
The National Weather Service (NWS) issued a dense fog advisory across 78 counties in Georgia, South Carolina and Florida on Friday morning, warning of extremely low visibility on roads.
While this kind of fog is unrelated to nuclear radiation and generally should not endanger human health, officials have previously warned that dense, low-level fog can also impact air quality by trapping local pollutants close to the ground.
The hazardous warnings specifically impact drivers throughout the region, as Americans won’t be able to see beyond a quarter-mile in front of them during the morning hours.
Meteorologists noted that central, eastern and southeastern Georgia, central and southeastern South Carolina and parts of the northern Florida Panhandle are largely covered with fog.
Large portions of these three states could see more than five inches of rain fall by Saturday.
Most of the dense fog advisories on land will stay in effect until at least 10am ET this morning, meaning the thick fog should start lifting as the sun rises and warms the ground.
A few coastal and marine areas have longer alerts that last until 1pm Friday, including the waters off the Georgia and South Carolina coasts, Charleston Harbor, and some Florida Panhandle bays.
A large fog belt has formed over the US Southeast, causing travel disruptions Friday morning
Major cities dealing with this thick fog include Augusta and Macon in Georgia, and Columbia and Charleston in South Carolina.
Satellite images from the National Oceanic and Atmospheric Administration (NOAA) revealed the dense fog forming over the entire Southeast early Friday morning, including over parts of Alabama, Mississippi, North Carolina, and Tennessee.
NWS has not issued any alerts for radiation fog in these states, but did signal flood watches in Alabama, Mississippi, and Tennessee due to a ‘moist airmass with a slow-moving surface boundary’ moving through the region.
Dense fog like this often forms overnight and lingers into the morning due to a combination of weather factors.
In this case, recent rain or high humidity in the Southeast has left excess moisture in the air. Overnight, under clear skies and light winds, the ground cools rapidly after sunset, releasing heat back into the air and creating dense, low-lying fog.
Before this thick fog burns off throughout the day, toxic particles from factories and car exhaust can hover over populated cities for hours, forcing anyone in the fog to breathe in plumes of dust and chemicals that can exacerbate respiratory problems like asthma.
Some Georgia residents have claimed on social media that dense fog belts this week have smelled like chemicals and other hazardous substances while walking or driving through the clouds.
‘We have had foggy mornings for the last week in NE Georgia. And it’s not normal fog, it smells like burning plastic and leaves a residue on our car windows,’ another person claimed Thursday.
The National Weather Service has issued dense fog advisories in three states, and also issued flood watches for nearby areas due to excess moisture in the region
That X user also pleaded with Health Secretary Robert F Kennedy Jr to investigate the suspicious particles in Georgia’s fog.
Radiation fog is quite common in the southeastern US, as it forms when the ground cools quickly overnight under clear skies and calm winds, turning moisture in the humid air into thick fog close to the surface.
Radiation fog is most often seen during the fall and winter months, when longer nights allow for more cooling, cooler temperatures, which help the air saturate faster, and loads of moisture from seasonal storms.
‘If driving, slow down, use your headlights, and leave plenty of distance ahead of you,’ NWS officials wrote in their warning.
