SPOKANE, Wash. — The west coast is expecting heavy rain for the next week with some areas expecting as much as 5 or 6 inches of rain!
All this moisture is arriving via what's known as an atmospheric river in the Pacific Ocean.
Atmospheric Rivers are columns of humid air that is transported with a low level jet stream typically from the tropics to the Pacific Ocean, near Hawaii, to the western U.S. The location and strength of the atmospheric river can vary. Strong atmospheric rivers can be devastating with flooding and debris flows. But weaker atmospheric rivers often are beneficial, especially to drought stricken areas.
Most of the western U.S. is suffering from a bad drought, with 46% of California, 27% of Oregon, and 25% of Washington currently under an exceptional drought, the most severe category of drought conditions. So the rain will be mostly seen as a very welcomed sight.
There are three separate events that will set up. The first being on Wednesday, the second being on Friday, and the third arriving on Sunday.
For Spokane - eastern Washington, being on the east side of the Cascades will see far less rainfall than the western side of the state. Estimates are the the 7-day rainfall totals will be around 1.5 inches. Compare that to the 2-3 inches expected for Seattle and the Puget Sound.
The Wednesday event will be just light scattered showers for the Inland Northwest. Starting largely after 7-9 a.m. and ending by 3 p.m., rain will be sporadic and accumulations around one-tenth of an inch.
The bigger rainfall will occur during the evening hours Friday with the second event, and between Sunday and Monday with the third event. This is where the 1 to 1.5 inches of rain is more likely to accumulate with washout-like rainfall.
Atmospheric rivers tend to be fairly mild weather pattern, so this will easily remain a purely rainfall event for eastern Washington and North Idaho. Snow levels likely stay above 5,000-6,000 feet and may dip closer to 4,500 feet over the weekend.
