Southeast's sweltering summer heat wave brought air quality concerns
Unusually early and unusually warm summer weather in Inner Southeast gave way to a genuine heat wave in early August, and although the worst of the heat broke after a light overnight rainfall on August 13, THE BEE learned from a professional weather forecaster that it could remain warm into September.
NOAA National Weather Service Portland Bureau Science and Operations Officer Bill Schneider explained the unseasonably hot spell for us.
The science behind hot summers, Schneider said, is that high pressure systems in the atmosphere compress the air, causing it to heat up, and forcing it outward.
The hot air scours out clouds that can shield us from the hot sun's rays. "And, we have more of an 'offshore' flow, so the winds are coming from the east and going to the west, and blocking the cold, moist marine air which often influences weather here – keeping away this kind of a natural 'air-conditioning' we often enjoy," explained Schneider.
It's not totally unprecedented weather, he said -- it has been comparable to the heat wave of August of 2009, when high temperature records were set.
Surprising many, Portland Parks & Recreation closed outdoor swimming pools on August 3rd and 4rd, "due to the metro area's Air Quality Alert and current Unhealthy Air Quality Index rating," said Portland Parks Bureau spokesman Mark Ross.
As the first week of August progressed, unusually high temperatures were accompanied by unusual smoke and haze, caused by wildfires burning in British Columbia 300 or more miles away. That caused the Oregon Department of Environmental Quality to issue an "Air Quality Alert" which stayed in effect for nearly two weeks. However, the worst of the smoke had cleared in Inner Southeast by Sunday, August 6.
Asked to look into his crystal ball and forecast this fall's weather, Schneider said, "It's a little bit early to tell what is going to be. We look at large-scale weather patterns to give us an indication how conditions might be in the future. Right now, we're in a 'neutral phase', as far as El Niño and La Niña weather patterns are concerned; so I expect we'll have fairly close to 'normal' conditions.
"But, there are many things are going in the atmosphere that can influence that," Schneider hedged.