"The average atmospheric river carries an amount of water vapor roughly equivalent to the average flow of water at the mouth of the Mississippi," NOAA states.

The first bomb cyclone hit earlier in the week, and was blamed for two deaths in Washington. Photos of the damage showed cars and homes smashed by fallen trees. Meanwhile, the eastern part of the country was getting its first real taste of winter weather with a storm that promised to dump rain and even a foot of snow at higher elevations in parts of Pennsylvania,