Here is an example of the view on an ordinary foggy night, June 17, 2016 at 1:16 (I have other screenshots from this day that show fog encroaching on reactors).
Below are some samples from today's screenshots:
The view today caught my attention because of the light's intensity and asymmetry.
One explanation is the plant lights were simply reflecting oddly in encroaching fog.
Another is that atmospheric radiation in that area burns off fog so as to amplify the light (although that doesn't explain the light moving north).
Another explanation is something in the harbor is the source of the light and the strange fog that came in so suddenly today.
Here are more screenshots: https://www.dropbox.com/s/ua91y77r7r5we62/July%201%202016%20Event%20final.pdf?dl=0