In detail , the volcanic mountain erupted due to underneath pressure in the magma ,
This hot magma are forced out through the vertical vents under the pressure leading to the top most part of the mountain to be blown off for magma to flow and solidifies mostly on sides of the mountain .
The whitish ash which is hot composed with calcium carbonate strikes with atmospheric elements like Oxygen, Hydrogen , carbon dioxide, and other luminous element that are either positive and strikes with positive resulting into THUNDER and LIGHTENING on clouds , thank you for the post