Freezing fog creates near-zero visibility and slick roads early Thursday

Drivers in Calgary woke up to a thick layer of freezing fog.

Freezing fog can occur when saturated air (fog) forms in temperatures below freezing and, similar to freezing drizzle, deposits a layer of rime or glaze (ice) on surfaces that are also below freezing.

This scenario can be especially dangerous for drivers as it produces icy surfaces in conditions of low visibility.

The winds in and around Calgary were minimal early Thursday and, without any mixing of the air closer to the surface, the freezing fog is likely to linger throughout the morning commute.

Later in the day Thursday, temperatures will remain cooler across the region with a persistent weather pattern continuing to funnel Arctic air from the northwest to southeast corners of the western Prairies.

Relief is expected at the end of the weekend with a shift in this weather pattern.

Strong winds will likely be the first indication of this change as westerly flow sets up across the Rockies.

Monday will be the warmest day (and the first day above freezing) in over two weeks.

The daytime high on Monday is forecast to reach at least 0 C, or 10 degrees warmer than Sunday’s high.