Visibilities in the region have been reduced since early Monday, almost as though the entire region has been in a haze.
Various reports have attributed at least some of that to smoke from the horrific California wildfires. The air has at times around here had a rather acrid odor; however, it is uncertain just how much the California fires have to do with it.
An "experimental" forecast map, posted Monday morning by NOAA's Earth System Research Lab, in Colorado, showed a plume of California smoke passing through the Philadelphia region Monday afternoon.
Gary Szatkowski, former chief meteorologist of the National Weather Service Office in Mount Holly, tweeted it out and it drew plenty of attention.
Joe Minott, longtime chief of the Clean Air Council, says it's quite possible the smoke made it here – "It makes perfect sense," he said — and that given Earth's rising temperatures, the nation could expect more wildfires and migrating smoke.
However, he said he couldn't be absolutely certain the region was inhaling it.
The Pennsylvania Department of Environmental Protection's air quality discussion on Monday mentioned "stagnant and foggy conditions;" nothing about smoke.
If it was smoke from the West, it wouldn't be the first time that plumes had traveled thousands of miles to the East Coast, noted Dave Dombek, a meteorologist with AccuWeather. One of the classic examples was the incredible fallout from the 1980 Mount St. Helens eruption in Washington State.
But whether a California plume actually made all the way to Philadelphia this week would be impossible to verify, according to John Leslie, spokesman for NOAA's satellite division. The problem? Satellites can't see through clouds.
Alex Staarmann, a meteorologist at the Mount Holly weather service office, said the locally reduced visibilities have been the result of fog and haze. Smoke plumes likely would have passed overhead at jet-stream level, he said.
In any event, Monday would have been a bad air-quality day even without the smoke, the experts say. Air at the surface was capped under an "inversion," which inhibited the dispersal of pollutants, said Dombek.
Warm air rises over cold air, except when it bumps into a warmer layer. On Monday the air about a mile up was 2 to 4 degrees warmer than the layer below, said Staarmann. Plus, winds at ground level were nearly dead calm.
"There was no mixing whatsoever," said Dombek.
The atmosphere evidently is about to restart the mixer. Winds Tuesday afternoon were expected to gust to 20 mph, and closer to 30 on Wednesday.