Impact of downslope easterly wind event on air quality: 13 December

 Strong downslope winds developed overnight on 13 December 2023. Hig winds extended westerward across the Valley. Note the turning of the wind to the north and south in the western portions of the Valley.

Mobile PM2.5 observations help to illustrate the clean air resulting from the easterly winds relative to higher PM2.5 concentrations in other areas to the north and south.