Up to 15 inches of rain fell in parts of western Washington in the last seven days pushing rivers over their banks and producing significant flooding.
Homes, roads and streets have been submerged and some people even had to be rescued over the weekend
Ahead of the storm 16 states from California to Iowa are under snow, ice and wind alerts.
This morning, the complex storm system is moving over the Rockies and a Winter Storm Warning has been posted for Salt Lake City where more than a foot of snow is forecast.
A Winter Weather Advisory has also been issued for Denver where three to seven inches of snow is forecast today with up to two feet in the mountains just west of the city.
By Tuesday, a storm system moves into the central U.S. with severe storms expected in the South, including damaging winds and even a few tornadoes.
To the north, snow will fall from Colorado to Iowa with several inches expected there.
By Wednesday, the storm system will stretch from the Plains into the Gulf Coast with damaging winds and a threat for tornadoes in the Gulf Coast and heavy snow possible from western Texas into Oklahoma and into parts of Missouri.
By Thursday, the strongest part of the storm system will reach the East Coast with thunderstorms that could produce damaging winds in the Carolinas and Florida and heavy rain and some snow and ice in the Northeast for what could be a messy end to the week.