Air Quality In Calgary Off-The-Charts Bad From Forest Fires - Between 500 and 600

[hatrack]

https://www.washingtonpost.com/wp-apps/imrs.php?src=&w=691

On Tuesday, smoke from wildfires raging in Alberta descended over Calgary, the province’s largest city. Air pollution climbed to double the level considered hazardous, while the thick haze gave off an acrid smell, glowed orange and reduced visibility to half a mile. The smoke was so thick in the region that its air quality was among the worst in the world, and it is expected to remain similarly poor Wednesday and perhaps longer as the Alberta fires continue.

As many as 150 active fires are burning across Alberta and British Columbia. In Calgary, about 300 miles from some of the largest blazes, the smoke settled near the ground. Now, the high-altitude winds of the jet stream are carrying this smoke into the Lower 48 states. Scenes in Calgary were reminiscent of Seattle last summer and San Francisco in 2020 as wind currents blew smothering wildfire smoke into those population centers, compromising air quality.

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A provincial state of emergency remains in effect for Alberta as a result of wildfires concentrated in the northern half of the province. Mandatory evacuations were ordered Tuesday for the town of Swan Hills, about 100 miles northwest of Edmonton, Alberta, the latest population center to be threatened by flames that have already burned twice the normal annual acreage across the region. Wildfires that have been burning for weeks in western Canada were initially set off by lightning storms in early May. Although firefighters gained a brief upper hand last week, the latest round of record heat and abnormally dry conditions intensified the blazes while also fueling new ones.

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As a cold front passed Calgary on Tuesday morning, it opened the gates for a torrent of smoke to surge southward. The air-quality index vaulted from 46 (good) at 5 a.m. to over 500 (very hazardous) by 10 a.m. “At this range the breathing and health of all individuals is impacted,” meteorologist Jayson Prentice wrote on Twitter. Some air-quality readings in the area at times surpassed 600, essentially off the charts. Areas of thick smoke and poor air quality remained entrenched across British Columbia, Alberta and Saskatchewan on Wednesday morning.

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https://www.washingtonpost.com/weather/2023/05/17/calgary-wildfire-smoke-alberta-united-states/