Lowering Lid

The changes are subtle, but over the past three days, the inversion has gradually lowered and strengthened, reducing the depth of the valley cold pool through in which pollution is trapped.

A quick look at the air quality data shows we have exceeded the National Ambient Air Quality Standard for 24-hour average PM2.5 in several counties including Utah, Salt Lake, Davis, Weber, Cache, and Tooele.  This is a regional scale event with a large fraction of Utah's population impacted.

In Salt Lake, our 24-hour average PM2.5 presently sits at about 60 ug/m3.  Despite a drop in hourly PM2.5 overnight, there seems to be little reason not to expect the longer term upward trend to continue.

Source: Utah DAQ

Our first opportunity for a bit of stirring will be mid week.  The models still lack consensus, however, concerning how much of a mixout we may get.  Keep your fingers crossed.