The media is going on about lazy atmospheric rivers as a non-threatening term for precipitable water ocean plumes caused by major convection.
But these are full-fledged storms, created by a storm factory.
This is the one in the Pacific. The Siberian Arctic spill creates a storm in one day, and then the Bering Str. spill makes it bigger, and it hits California. The 'atmospheric river' is just a naked benign plume that hits the mountains to make it rain. These are monsters.
Now, in surprising news, the exact same thing is setting up for Europe. They will soon be the new California.
Since the benign warm air is always there, the 'Godzilla' factory will continue until the headpond of cold air drains out. Probably in a month, like last time. Then everybody can dance and sing while it fills up again.
ps. Interesting that this is an entirely different mechanism from standard belt typhoons and hurricanes. Should be studied more .... Ha!