Residents in downtown Toronto and the Greater Toronto Area awoke to a dense fog on Sunday morning, prompting many to share the sight on social media. Not only downtown residents, but those on the Toronto Islands also noted the “city disappearing.”
The thick fog was also experienced by a cyclist on the Leslie Spit.
While some were confused whether they were “low-lying clouds,” “fire” or fog, Now Toronto reached out to Environment Canada and got the answer!
The national weather agency issued a fog advisory on May 26, and Geoff Coulson, a warning preparedness meteorologist with Environment Canada, confirmed that it was a “typical occurrence of radiation fog,” and “not poor air quality.”
While the name for the fog may sound scary, it actually has a cool science behind it that is not so frightening..
Coulson explained that it tends to form a day or two after rainfall when there is still moisture near the surface, with the essential ingredients being recent rainfall, clear skies overnight, and light winds.
This type of fog typically develops overnight when the skies are clear and the wind is light, with some moisture near the ground. As temperatures drop, if the air near the ground is moist enough, it can reach saturation, leading to fog formation. The period of lowest visibility for radiation fog typically occurs between 4 a.m. and 9 a.m.
However, many residents shared that the fog in downtown lasted past 1 p.m. When asked the reason for that, the meteorologist shared that, “closer to the lake, the fog can persist as moisture levels stay higher. The further inland you go, the quicker the fog tends to improve.”
“As the sun rises, it warms the ground, causing the fog to lift and dissipate as the moist air mixes with drier air above,” he added.
Share your fog pictures and videos from this weekend on our social media, and let us know what you thought it was!
