Capital Weather Gang readers queried on Twitter reported smelling smoke all over the region.
In a forecast Tuesday, the National Weather Service predicted that the jet stream, the fast-moving current of upper level winds, would carry smoke across the country but had expected it to remain “above the surface.”
However, some of it has found its way down toward the ground.
Joel Dreessen, an air quality forecaster for Maryland’s Department of Environment, confirmed the smoke is affecting the air we breathe. He said the smoke had wafted over the air above us for “many” days but had “made its way to the surface in noticeable fashion” as of Thursday. He noted that several constituents of smoke were detected in elevated quantities including fine particulate matter, carbon monoxide and black carbon.
A Code Orange alert, signifying unhealthy air for sensitive groups, was issued for Baltimore and northeast Maryland on Thursday. The smoke pollution is adding to the effects of noxious ground-level ozone, which is elevated because of the hot, stagnant air in place.
“Dirty air, comprised of some wildfire smoke and residual pollution from Wednesday will be concentrated beneath a nocturnal inversion Thursday morning,” said the air quality discussion from Maryland’s Department of Environment on Thursday. “This should cause ozone concentrations to quickly increase after sunrise.”
In the Washington region, the air quality index was not expected to reach unhealthy levels but to instead hover in the moderate range. Ryan M. Stauffer, an air quality expert at NASA, noted concentrations of fine particulates, probably from smoke, were elevated at a monitoring station in the District but “not exceptionally high.” A cold front moving through the Mid-Atlantic on Saturday should clear any smoke in the air by Sunday and early next week.
In the mean time, the smoke could make the sky a little more hazy and cast an orange tint on sunrises and sunsets.
The subtle haze of smoke in the Mid-Atlantic is rather mild, compared with the thick plume that has consumed many parts of the West. On Wednesday, the air quality in Seattle tanked to its worst level on record.
The National Weather Service’s smoke report Wednesday said the fires in both the western United States and western Canada were producing “tremendous amounts of smoke with an enormous area of varying density” over much of Canada and the Lower 48, except for parts of the South.
Yet the smoke was not contained to North America. Satellite imagery showed the smoke becoming entrained into the circulation of Subtropical Storm Ernesto in the northern Atlantic Ocean.
Model simulations even showed smoke reaching Ireland and Britain.
It is not terribly unusual for smoke in the West to reach the eastern United States. In 2015, smoke from wildfires in western Canada reached the D.C. area.