Pennsylvania under a code red air quality alert as smoke continues to spread south from Canada

All of Pennsylvania is again under a code red air quality alert Thursday as smoke from the Canadian wildfires spreads across the state.

The average Air Quality Index readings for the entire day will likely be in the Code Red range, however local conditions could be Code Purple throughout the day. Residents are encouraged to check www.airnow.gov for their local conditions.

Concentrations of smoke will likely be high throughout the day in western Pennsylvania and increasing throughout the day in eastern Pennsylvania.

Smoke from the wildfires is expected to impact Pennsylvania air quality throughout Thursday and Friday, with some possible relief on Saturday. DEP will continue to update the forecast.

Conditions will likely be worse in the morning as a natural weather phenomenon called an atmospheric inversion will keep smoke filled air closer to the surface and prevent air from higher elevations to mix with air closer to the ground. Residents are encouraged to check www.airnow.gov for current conditions in their area.

On a Code Red Air Quality Action Day, young children, the elderly, and those with respiratory problems, such as asthma, emphysema, and bronchitis, are especially vulnerable to the effects of air pollution and should avoid outdoor activities, and everyone else should reduce prolonged or heavy exertion.

In Code Purple conditions, young children, the elderly, and those with respiratory problems should avoid all physical activity outdoors. Everyone else should avoid prolonged or heavy exertion.

While it’s not expected to be quite as bad for southeastern Pennsylvania as the round earlier this month that drove air quality levels to “hazardous” levels, it will still be enough to make the air “unhealthy” for all groups.

Western parts of the state were expected to get hit hardest, prompting the state Department of Environmental Protection to issue the code red alert for that region first, but the smoke progressed further east overnight than projected, according to the forecast from AirNow.gov. Around 10 a.m., the DEP expanded the code red to the entire state.

“Air quality conditions degraded overnight as more smoke from the wildfires pushed into Pennsylvania from the Great Lakes region,” according to the forecast.

Fine particulate concentrations from the smoke will increase over southeastern Pennsylvania by midday, with the highest levels expected later in the day “as the smoke continues to advance south and eastward,” according to the forecast.

When a code red alert is issued, everyone should reduced prolonged outdoor activity or heavy exertion. Sensitive groups, including the elderly, young children and those with breathing difficulties, should avoid all outdoor activities, according to the DEP.

Smoke from the wildfires is expected to linger over Pennsylvania through Friday, according to the DEP.