Sunday, January 6, 2013

Frightful Conditions

PM2.5 conditions and trends continue to be frightful.  Data from the Utah Division of Air Quality shows that Utah county is now officially in the "unhealthy" category, which means 24-h PM2.5 concentrations are above 55.4 ug/m3, up from "unhealthy for sensitive groups."  Salt Lake and Cache Counties are also approaching that "unhealthy" category.


Unfortunately, the models have flopped back to a solution that splits the system moving into the western US early this week.  This gives us little hope for a full mix out in the near future.  There's just a slight increase in flow and cooling at mountaintop level, with some high clouds and perhaps a spot or two of snow.  I'm not hopeful for anything more than perhaps a slight drop in air pollution levels.

Our best hope for a more major mix out is later in the week when a strong front moves into the state.

Right now, the models suggest that front should at least partially if not fully mix out the inversion, but it is dangerously close to a splitting system.  We will have to watch and see how things look during the week.

As PM2.5 levels continue to climb, it would be interesting to hear how this event compares to others during the past decade.  Based on the PM concentrations above, it seems this is an event for Utah and Salt Lake Counties that is getting up there amongst the worst events over the past decade (perhaps not so for Cache County).  Anyone out there have hard numbers?  

1 comment:

  1. They took away my CHPC account so the graphs aren't there (I have them here on my hard drive), but back when PCAPS was starting up I grabbed some historical data from some stations in the valley and threw them up at
    It's just daily/semi-weekly mean PM2.5 data, but there have been a few days in the past where the mean was > 80 ug/m3. It's bad, but I'm guessing there have been a few worse.