Canadian smoke is filling Philly’s skies and is expected to linger through Wednesday

Dense, acrid smoke from the Canadian wildfires that shrouded much of the Northeast like a fog bank and filled the skies over the Philadelphia region Tuesday evening, and was expected to linger through Wednesday.

The smell was so evident that Montgomery County reported that it had received “a significant influx of 911 calls” reporting “a burning odor.”

The smoky haze, which reduced visibility to two miles at Philadelphia International Airport late Tuesday night, was due to persist through at least Wednesday, and officials in both Pennsylvania and New Jersey have issued air-quality alerts, advising people with respiratory or heart conditions to exercise caution.

The worst of it was forecast for Wednesday afternoon into the evening, the National Weather Service said.

The entire Philadelphia region and most of New Jersey had been under “red flag” alerts for “critical fire weather conditions” Tuesday as a dry spell that already has set a record in Philly persisted.

The smoke from the Quebec fires was riding winds from the north behind a cold front that touched off at least a few random showers that wet the ground and pelted some places with hailstones Tuesday, but certainly nothing that would have an impact on the deepening deficits. Officially, all of 0.02 inches was measured in Philly.

One measure of how moisture-starved the region has become lately is the fact that the government’s Storm Prediction Center had warned of possible “rare dry thunderstorms” — as in sound and lightning without water.

The air was dry enough to evaporate raindrops before they hit the parched dirt, said Mike Lee, a meteorologist with the National Weather Service in Mount Holly.

» READ MORE: Philly had its driest May on record

Last month was the driest May on record in Philly, and in the last 37 days, officially Philadelphia has received 0.26 inches of rain, which comes to about a drop a day. Rain deficits have been deepening throughout the region, and Bucks County residents are being asked to conserve water.

Humidities dropped below 30% Tuesday afternoon.

“That’s pretty dry for this time of year,” said Lee. Under normal conditions, water would be evaporating into the atmosphere from the lush foliage, which is now unusually dry.

But even the fire danger was high, it was the smoke from the Canadian wildfires the people around here were seeing and sensing Tuesday evening.

The NOAA forecast called for the smoke to linger through Wednesday.

» READ MORE: Major wildfires also are a threat in the Philly region and the East

As for rain, Lee said the next shot at significant precipitation would be perhaps Sunday night into Monday.

“We’re keeping an eye on it,” he said. “A whole lot of people are wishing for rain.”