In a tragic incident north of New Orleans, Louisiana, a dangerously thick and rare phenomenon known as "superfog" contributed to a devastating 158-vehicle pileup on Monday. According to local officials, the superfog was exacerbated by wildfires burning in the vicinity, resulting in seven fatalities and more than two dozen injuries along a stretch of Interstate 55.

The series of accidents occurred on both the northbound and southbound lanes, leaving behind a trail of crumpled and charred vehicles. The primary cause of these collisions was an unusually dense layer of fog, referred to as superfog, which occurs when moisture in the air combines with smoke from wildfires that burn brush, leaves, and trees in the swampy marshlands of Louisiana.

Under these low-visibility conditions, the superfog reduced visibility to less than 10 feet, and in severe instances, approached near-zero visibility, as reported by the National Weather Service. The agency explained that in calm wind conditions, superfog tends to move through low-lying areas such as creek beds or drainage ditches before settling over highways. This dense fog presents a significant danger to motorists.

Although the thickest superfog occurred early on Monday, dissipating through the afternoon, fog advisories for a small portion of the state remained in effect until Tuesday. Instances of superfog are uncommon but periodically occur in the South, particularly in areas where marsh fires, minimal wind, and humidity combine to create thick veils of fog.

The New Orleans branch of the weather service noted multiple ongoing marsh fires in the region, suggesting a potential link between these fires and the development of superfog conditions. Local officials emphasized that the dense fog heavily impacted sections of the interstate and advised individuals to exercise caution or avoid the area altogether.

In the face of near-zero visibility, the weather service in New Orleans urged drivers not to stop on the road, as it would significantly increase the risk of accidents. Instead, motorists were advised to pull off to the shoulder or seek the nearest exit to surface streets if uncomfortable driving in such dense fog conditions.

It is crucial to note that while superfog reduces visibility, it differs from smog, which arises from the interaction between fog and air pollution, contributing to hazy conditions and potential health hazards.

Louisiana, grappling with extreme drought conditions, has experienced an increase in marsh fires, making the emergence of superfog more likely. As such, it is essential for individuals in affected areas to exercise caution and stay informed about hazardous weather conditions to help prevent tragic accidents like the one witnessed on Interstate 55.