Wildfire Smoke Impacts Delmarva

On Tuesday, smoke from wildfires in eastern Canada created grey and hazy skies across Delmarva; scenes usually associated with high humidity days in the middle of the summer. It’s not unusual for the Mid-Atlantic region to see wildfire smoke in the summer, but this typically occurs from fires in the western U.S. and Canada with smoke spreading eastward in the higher levels of the atmosphere. This week’s event comes from much closer to home, with raging wildfires in Quebec, Canada. And because of closer proximity, much of the Mid-Atlantic and Northeast was locked in thick smoke close to the surface, creating dangerously low air quality levels. Smoke levels at the surface were thick enough to prompt an Air Quality Warning for most of the Delmarva peninsula on Tuesday.

Sunrise on Delmarva Tuesday morning, from Beth Sparaco

The fires in eastern Canada have been unprecedented both in size and for this early in the warm season. The cause has been the work of a “heat dome” – a large area of high pressure with sinking air to limit the development of clouds and rain while also promoting warmer than average temperatures, creating an extremely dry environment and increasing the chance for wildfires.

In the past few days, strong high pressure near the Great Lakes has buffered up against an area of low pressure off of the New England coast, and as the fires have burned in-between the steering currents aloft between the two pressure systems have been guiding the plumes of smoke directly south into the U.S.

With a more westerly flow developing on Wednesday, some of the thicker smoke will be nudged out to sea. However, smoky skies and times of lower air quality may persist in the coming days as fires continue to burn in parts of eastern Canada, with steering currents at times guiding more smoke southward.