Ign did an article about what Cersei may be planning, and I wanted to see what y'all thought.
Originally I thought she would burn the Tower of the Hand. But then I thought it made more sense for her to destroy the Sept, but in Bran's vision in a very brief flash we see the tunnel where the Wildfyre is stored exploding.
The Mad King wasn't able to ignite the Wildfyre so that moment must be a future event. What if Cersei's plan isn't to burn just the Sept, but is instead planning to ignite all the Wildfyre under King's Landing and burns down a huge chunk of King's Landing?
Which leads me to another pic. A moment from Dany's vision in season 2.
That may not be snow on the ground. Maybe it's ash. Maybe it's falling because Cersei burned down King's Landing.