Following a very wet pattern last week, AccuWeather forecasters warn that additional rain is on the way for the Northwest this week that will heighten the risk for widespread flooding.

Atmospheric rivers caused flooding in the Pacific Northwest this month.

By David Ryder and Steve Gorman SNOHOMISH, Washington, Dec 11 (Reuters) - Heavy rains drenching the Pacific Northwest triggered flooding on Thursday across much of the region from Oregon north through Washington state and into British Columbia,

The Pacific Northwest is expected to see up to seven inches of rain this week, as the eastern United States braces for arctic cold.

Now that hurricane season is over, the Hurricane Hunters at Keesler Air Force Base are tracking another kind of atmospheric phenomenon. These are pictures of the two Keesler-based WC-130J Super Hercules Aircraft patrolling the skies over the Pacific Northwest to monitor an atmospheric river.

Meteorologists caution that the Pacific Northwest may face weeks of winter storms capable of triggering flooding, mudslides, and avalanche dangers.

The National Oceanic and Atmospheric Administration is sending its famed reconnaissance aircraft into a powerful storm system that threatens widespread flooding and damaging winds for Western Washington from Monday through Wednesday.

An arctic air blast swept south from Canada, spreading into the northern United States. Meanwhile residents of the Pacific Northwest braced for possible mudslides and levee failures as floodwaters slowly recede.