Near-zero visibility around Calgary early Friday with increasing avalanche risk in the Rockies

Dense fog blanketed the Calgary area early Friday, creating near-zero visibility and prompting a yellow-level fog advisory to be issued by Environment and Climate Change Canada (ECCC).

Persistent moisture continues to funnel into the B.C. coast and track toward the Rockies as an atmospheric river remains the main weather maker for that region.

Yellow and orange rainfall warnings have been issued for southwestern B.C., with ECCC explaining “periods of heavy rain will begin to taper off this afternoon” coinciding with a cold front expected to sweep in behind.

The combination of days of heavy rain creating rapid mountain snowmelt is increasing the likelihood of negative impacts associated with so much moisture falling over such a short period of time.

“Localized flooding is likely. Some roads may become impassable. Travel delays and/or cancellations are likely. Damage to some critical infrastructure is possible. Landslides may occur in vulnerable areas such as steep slopes, deforested areas or recent burn scars.”

On Thursday, a number of major highways in B.C. were closed as crews worked to manage and mitigate an elevated avalanche risk. According to Drive BC, many of those closures continued Friday morning and are expected to last into the weekend.

On Friday, areas west of Calgary—including portions of Banff National Park—were rated by Avalanche Canada as having an extreme avalanche risk (the most dangerous rating possible).

As of 9 a.m. Friday, Drive BC cameras showed wet road conditions where rain was falling and water was pooling from recent snowmelt.

In southeastern B.C., rainfall warnings and special weather statements were issued by the national weather agency.

“An atmospheric river continues to impact southern B.C., delivering 30 to 50 mm of rainfall to the region through the evening. This is in addition to what has already fallen in the area this week.”

Snowfall warnings were issued in Alberta near the Columbia Icefields and around the capital region, with up to 15 centimetres of snow expected.

Wind warnings were issued again for southwestern Alberta with wind gusts forecast to reach 100 km/h on Friday.

In Calgary fog is expected to dissipate throughout the afternoon, with a high of 16 C expected by the afternoon.

Cooler air will descend from the north on Saturday, and temperatures will drop significantly across Alberta. Calgary’s high on Saturday will be 2 C, 14 degrees colder than on Friday.

Scattered flurries are possible around central and southern Alberta on Saturday; however, warmer surface temperatures should help with melting on surfaces like roadways and sidewalks.