Hazy skies and a 'campfire' smell have seemed to be a weekly event this spring across the Northeast, and we're not even in peak fire season yet! While seeing smoke from wildfires in the region isn't anything new, the sheer distance that the smoke has traveled is certainly impressive. The main questions here are: why are the fires in Canada already so severe, and what's been causing the smoke to extend for almost 2,000 miles?
Over the last several weeks or so, we've seen an unusually strong and persistent area of ridging take shape over western Canada. This has allowed temperatures to soar to record levels, with many locations having their warmest spring in over 80 years! Additionally, this pattern has kept the region remarkably dry. In fact, portions of northern Alberta saw only around 10 - 25% of their normal monthly precipitation for May. To make matters worse, this abnormally dry pattern has shifted into eastern Canada too, closer to the northeast quarter of the U.S.
(Image Credit: Brian Brettschneider)
The combination of the record temperatures and lack of rain has allowed conditions to become very conducive for explosive wildfire development, which has overwhelmed firefighting efforts until recently. The fires continue to rage on, becoming some of the most severe in the modern era. More than four million hectares in Canada have been scorched in what has been a record-setting spring and an unprecedented start to the wildfire season. Officials have responded to 520 fires so far this year, overwhelming control measures. The previous high for the spring season alone was 615,000 hectares burned in 2019. The most recent fires in Quebec most likely sparked from lightning, and have quickly expanded, providing the source of all of the horrible smoke and air quality on the East Coast.
(Image Credit: CBA)
So why all the smoke? Over the last several weeks, we've seen a very "blocky" pattern develop across the Northern Hemisphere that would typically be quite favorable for snow lovers across the East Coast. Instead of cold air being funneled down from Canada, we've seen copious amounts of smoke spill into the region and remain trapped for days due to "troughiness" over the Northeast. While much of the smoke over the last few weeks from the Alberta fires has remained above the surface, the smoke from the out-of-control burns over Quebec has been able to reach the surface, which has prompted "health emergencies" across several cities in the Northeast. Many cities have seen some of the worst air quality on Earth over the last week and some surpassing records. For example, Washington, DC, is on pace to break their previous "worst" air quality day, which was set back on July 4th, 2000, from firework celebrations!
(Map showing strong ridging (in red) & steering winds over North America for May)
The good news is that a bit of a shift in the pattern may try to take shape over the next week, which will bring at least some rainfall to the hardest-hit locations in Canada. However, we still have to keep in mind that we're still very early in the fire season, which typically doesn't end until late October. Starting off dry in the season isn't a great place to be when you have several months remaining, and the developing El Nino may complicate things even further as it tends to favor reduced precipitation and warmer temperatures. While this doesn't guarantee another outbreak of this magnitude, we'll have to keep a close eye on how things develop throughout the summer months!
