Scorching heat and Canada wildfires could be tied to ‘wavy, blocky’ jet stream

Scientists say a closely watched atmospheric pattern — the jet stream — is behind both the Canadian wildfires and the scorching heat in Texas.

Scientists say a closely watched atmospheric pattern — the jet stream — is behind both the Canadian wildfires and the scorching heat in Texas, raising questions about how it shapes extreme weather events and whether climate change is disrupting its flow.   

The jet stream, a ribbon of air that encircles the Northern Hemisphere at high altitudes, drives pressure changes that determine weather across North America. The jet stream’s wavy pattern creates areas of high and low pressure. 

In recent months, the jet stream’s patterns trapped and stalled a ridge of high pressure over northern Canada, which caused a heat wave and primed the landscape for the wildfires that later sent smoke pouring into the Midwest and the eastern U.S. Earlier this month, another ridge of high pressure centered over Texas, sending temperatures soaring.

More than 100 million people in the U.S. faced either blistering heat or unhealthy air quality Wednesday.

In recent weeks, the jet stream has appeared unusual and disjointed, scientists say. Some researchers think climate change is disrupting its flow and causing it to bake regions in heat longer. They are concerned that changes in the patterns could cause extremes to increase more rapidly than climate models have projected as the world warms.