Snow squalls and low visibility could bring "near-zero" visibility to much of southern Ontario this weekend.

Environment and Climate Change Canada has issued snow squall warnings and special weather advisories for almost all of southern Ontario.

The snow squall warnings have been issued for the areas in and around Barrie, Owen Sound, Tobermory and Point Clark, Ont.

“Scattered snow squalls this afternoon will intensify and become more widespread this evening and continue through Sunday morning,” the federal agency said. “Strong gusty winds will also lead to widespread blowing snow.”

Much of the rest of southern Ontario – from London to Ottawa to North Bay, Ont. – are under special weather advisories.

“Scattered bands of heavy snow have developed across the area late this morning,” the advisory issued for the Toronto-area reads. “Snow combined with strong gusty winds will lead to visibilities suddenly reduced to near zero at times.”

In all areas, the agency is advising against non-essential travel.

“Travel may be hazardous due to sudden changes in the weather,” ECCC said.

“Visibility will be suddenly reduced to near zero at times in heavy snow and blowing snow.’