Canadian Wildfire Smoke Spreading Across North America

Smoke from Canadian wildfires is causing unhealthy air quality in parts of the Northern Plains and Midwest in the US, with air quality alerts in effect for eastern Iowa. Smoke suspended at higher altitudes is widespread from Quebec and Ontario through the Midwest and Great Lakes to the Mid-Atlantic and Northeast coasts. The smoke is being circulated by a slow-moving low-pressure system spinning between the Great Lakes and the Canadian Maritimes. A high-pressure "heat dome" building in over eastern Canada next week is expected to increase the fire threat there and could lead to more smoke pollution in the US.