This morning's sounding shows a deep inversion over the Salt Lake Valley. At the time of launch, the surface temperature at the Salt Lake City airport was -7ºC (19ºF), whereas temperatures from about 800 to 700 mb were above freezing.
Meanwhile, the valley remains mired in pollution. Yesterday, PM2.5 concentrations measured by the DAQ sensor at Hawthorne Elementary along 700 East peaked at 71 ug/m3, which qualifies as unhealthy. Although PM2.5 levels have lowered some, they remain just below the unhealthy for sensitive groups threshold. I suspect we will see another push to higher values today.
At the University of Utah, one can see how the pollution tends to push in during the afternoons, but then lower at night.
There is a weak front coming through tonight, but I don't think it's going to crack the inversion. We are probably stuck with it through the weekend.