Saharan dust layer is still a couple of days away; it's progress has been held up by a trough plus Franklin hanging around just off of the east coast.

Track it using the UWisconsin Saharan air layer tracking product: http://cimss.ssec.wisc.edu/tropic/real-time/wavetrak/winds/m8g10split.html. Note that not everything in red is Saharan dust; just that travelling across the Atlantic. The rest is very dry air that the algorithm they use is picking up, such as that off of the west coast of the US.

Most of what you are seeing today is just haze, created by the stagnant air flow in association with the upper-level area of high pressure. With sinking motion and light winds throughout the atmosphere (nor any rain to help things), there's not a whole lot to move out various particulate matter in the air.