Forecast Issued: Nov. 16, 2018 Forecaster: James Miller, USDA Forest Service Overall, air quality across Oregon has either improved slightly or remained unchanged compared to yesterday morning. Locations in the Portland to Eugene corridor have experienced slight improvement, but still remain in the moderate air quality category. The most improvement has been within the Portland metro area, where several locations experienced unhealthy for sensitive groups air quality yesterday morning whereas good to moderate conditions were in place this morning. Figure 1. The Air Quality Index at 8 a.m. on Friday, November 16, 2018. For the rest of today, favorable low-level winds and upper-level atmospheric conditions from a passing weak-weather disturbance should lead to continued air quality improvement in the Willamette Valley, with good to moderate air quality expected in more locations by tomorrow. Improved atmospheric mixing will also likely produc...