Smoke to increase in Calgary Wednesday, thunderstorms likely in southern Alberta

Wednesday started off hazy across much of Alberta, including in the city of Calgary.

As of 7:30 a.m., the Air Quality Health Index (AQHI) was at 3 (low risk) in Calgary, but forecast to reach 5 (moderate risk) later in the day.

The AQHI ranges from 1 to 10+.

Most of the smoke in Calgary and southern Alberta is coming in from wildfires in British Columbia, but the low-pressure system moving from northwest to southeast from northern Alberta is also drawing some smoke from the Alberta wildfires.

Instability will remain a concern for Wednesday.

Thunderstorms are expected to form along the foothills before tracking west to east in the late afternoon.

Calgary could see scattered showers and thunderstorms move through at a decent pace, so the greatest threats on impacted communities will be isolated pockets of heavy rain and small hail.

More rain is likely at the end of the week, coinciding with a brief dip in temperatures.

Calgary is forecast to see 10-12 mm of rain Friday, with the highest rainfall accumulations in central Alberta (west of the QEII Highway) and in southwestern Alberta.

Daytime highs by the end of the weekend will return to seasonal thresholds.