Smoke from the fires has been festering over California for days, but recently it was picked up by upper-level winds heading east. A band of haze stretches across more than a dozen states from Southern California to Massachusetts.
On Monday, the smoke was pooling over the Washington region.
“All indications seem to point to there being some smoke in the area from the California wildfires yesterday,” said James Boyle, a meteorologist for the Maryland Department of Environment. Fine particulate concentrations were high on Monday, and black carbon, which Boyle said is a good tracer for smoke, was also high during the morning and early afternoon.
On top of that, high pressure over the region is forcing some of the smoke particles toward the ground, which is leading to higher pollution levels. The air quality index is moderate over parts of Northern Virginia and Maryland on Tuesday.
The smoke is also enhancing sunrises and sunsets. Smoke is made up of tiny particles from wildfires, which can provide more points for light to bounce off and scatter. This leads to the enhancement of the red and orange hues you see. A deck of clouds near the horizon also has this effect, allowing the sun’s rays to reflect off the clouds and to our eyes.
The smoke will probably linger in the area until Wednesday night, when a strong cold front comes through. This is the second time this year smoke from California fires has significantly affected the Washington region.