ARkstorm flooding
© Unknown
A map of the flood area of the hypothetical ARkStorm event
Scientists are now warning Californians that the long-awaited 'big one' earthquake could be the least of their environmental concerns.

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.

The U.S. Geological Survey has now begun planning for the return of the ARkStorm, so named after the boat Noah used to escape the flood in the Bible. The capped-up 'A' and 'R' stand for 'atmospheric river'.

They have recruited 17 researchers and a string of agencies to work with local emergency crews and government officials across California to ensure that should it arrive, they would be best prepared for it.

The team says that a storm on the scale of that which struck in 1861 is 'inevitable' and it was widely considered the worst and longest on record.

USGS chief ARkStorm scientist Lucy Jones said the weather system will start in the Tropics due to atmospheric rivers of moisture forming, grow larger and gain speed as it travels to the West coast of America where it would become roughly the same strength as a hurricane.

It would take some weeks to form, which would hopefully give them time to better prepare when it arrived.

Comment: Well, it doesn't look like they were able to imagine the impact of the full force of such an event. Nature rarely works according to models, so from being in drought one moment, then California finds itself totally soaked with no end in sight. And AGW is not to blame as this is not a new phenomenon as the article details.

© KeystoneUSA-ZUMA/Rex Features
A California golf course is flooded during the December 2010 storms. Scientists predict that up to nine million homes could be flooded in the ARkStorm.
'We think this event happens once every 100 or 200 years or so, which puts it in the same category as our big San Andreas earthquakes,' she said.

'Floods are as much a part of our lives in California as earthquakes are. We are probably not going to be able to handle the biggest ones.'

Californians have a long history of coping with natural disasters, not least earthquakes as the state sits atop the San Andreas fault.

The most destructive earthquake to hit California was 7.9 on the Richter Scale in 1906, when more than 3,000 people died.

The 6.9 quake of 1989, also known as the World Series Earthquake, left 63 dead and nearly 4,000 injured but many more had their homes destroyed.