Many times I have noticed that particles in the atmosphere tend to increase rapidly on July 4th...with a reduction of air quality. I took a look this morning...and it was there again..above is the trace at Puyallup and Queen Ann Hill from the excellent web site of the Puget Sound Clean Air Agency (http://www.pscleanair.org/airq/aqi.aspx). As you might suspect, fireworks probably has something to do with this (the pale of smoke is often profound after all the official and unofficial fireworks). According to Mike Gilroy, the chief meteorologist for the agency, July 4 brings the worst air quality of the year.
Today is the last warm day west of the Cascades. A look outside or the latest high-resolution image shows an obvious change...more clouds--both at low levels and aloft (see image). I plotted the temperatures the last few days (see plot)...temps have been 10-15F above normal. Last night had very high minimum temps--in the 60s in several locations.
The ridge of high pressure over us is in the process of shifting east and the clouds are associated with an approaching offshore trough (see upper level maps for situation this morning and tomorrow). This trough will initiate an onshore push tonight and marine air will fill the western lowlands. So boaters should be prepared for the influx of marine flow from the SW tonight! Today will not be cool...the temperatures aloft are just as warm as yesterday and the clouds will thin...getting back into the 80s. But tomorrow will be very different...highs near 70F. Lots of clouds and a few scattered light showers...particularly on the western slopes of the Cascades. The trough should stay in place the entire week...so expect temps a little below normal.
