I really wish I had the coastal radar right now, it would have been a huge help to determine exactly what is going on and what will happen over the next few hours. September we will have it.
It looks like the rush hour will NOT be seriously impacted by snow. At 4 PM, it is snowing at Quillayute and Astoria, with only very light snow flurries over some locations in western Washington interior. The snow falling out of the cloud deck is light and most of it is sublimating before it reaches the surface. Strong easterly flow is really evaporating the moisture over Seattle and eastern suburbs (see radar). This will provide considerable protection from accumulating snow.
The radar is still in clear air mode and the intensities are very light. It is not even snowing at Hoquiam....a key upwind station from Seattle. It has started to snow at Westport, so it is starting to move in slowly. No snow reports over western Washington away from the coast except for northern Orcas Is.
Bottom line: you don't have to rush anywhere if you are living in western Washington outside of the far northern sections. No imminent significant snow for next two hours in the central interior (ie Puget Sound). The satellite suggests a more intense band offshore that would come in during the evening...but can't be sure. At the same time it is warming aloft as we speak. Stay at work. Enjoy happy hour. WSDOT doesn't need to be concerned about a rush-hour mess. At this point the high-res models seem to be doing well here.
This nowcast can be interactive....if you experience significant snow, leave a brief comment.