Another more deadly threat awaits the West coast of America - in the form of a biblical 'ARkStorm', which could bring death and destruction on a scale never before seen.
Walls of water 10ft high, rain falling in feet instead of inches, and nine million people's homes flooded during a hurricane-like megastorm that could last more than month.
The every-other-century event last happened in 1861 and left the central valley of California impassable.
The cost was impossible to quantify - but should a similar event happen today the damage could total more than $300billion.
Comment: Feb 16, 2017: It does not have to be a hurricane as continuous stormsystems loaded with water aka Atmospheric Rivers would be enough to create the scenario outlined here. Something that California is experiencing now in the beginning of 2017.