...after the hurricane-force winds, there would be vertical updraft. A large mushroom cloud would rise, containing dust and smoke, and firestorms would begin. The day would darken to night as the atmosphere was obscured... late global fallout located in the stratosphere, lasts for years. It produces nuclear winter with no sunlight, no rainfall, and a drop in temperature. Nuclear winter would blacken the atmosphere and obscure the sun, moon and stars...
"The Coming Holocaust" By Rance Taylor & "The Fate of the Earth" By Jonathan Schell
Here's a photo I took in Pellinge near Porvoo.
Experimenting with textures.