Fog
I woke up and just saw white outside. Then I got up and saw that the fog was relatively light - meaning that I could see buildings in New Jersey. The thin line of fog was pretty and atmospheric, and made me think of a noir movie or book or something by Paul Auster.

I think it was advection fog.

Taken at 6:30AM, from the Upper West Side looking out over the Hudson River to Edgewater, NJ.