Weekend Rainfall Will Help, But Not End, Inland Northwest Drought

Sep 17, 2021

Predicted rainfall totals from September 17 through the morning of September 19.
Credit National Weather Service, Spokane

Much-needed rain is a welcome sight on forecast maps this weekend. It will help quench wildfires and pare back a region-wide drought. But the National Weather Service says it is unlikely a rainfall deficit will be closed by year’s end.

As of September 16, Spokane had received 5.28 inches of rain – only about half what is considered average for rainfall by mid-September. Forecast rainfall amounts this weekend range from a quarter of an inch in the Moses Lake area to possibly two inches on the eastern slopes of the Cascades.

The rain won’t put an immediate end to wildfire season, says Steven Van Horn, a meteorologist with the National Weather Service office in Spokane. But it will definitely help.

“Over the entire region, this system is going to be quite wet. And it’s going to put a big dent into our fire season,” Van Horn told Spokane Public Radio on Friday.

The rainfall forecast for this weekend will also help reduce the intensity of an exceptional drought in the Inland Northwest. The drought began in March, according to the National Integrated Drought Information System. The situation was worsened by two record heat waves in the summer.

But closing the region’s rainfall deficit by the end of the year is unlikely. Van Horn said that shortfall got an early boost from an unusually dry spring.

“This is a very unusual stretch…usually we get some decent rainfall amounts in April, May and June, but those were few and far between during that period,” Van Horn said.

Seasonal climate outlooks offer a glimmer of hope: Van Horn says the latest outlook for October, November and December leans toward above-average rainfall in the area. Some relief will also come in the frozen form as snowfall begins later this year. But because the area is so far behind in precipitation, the drought is expected to last into early 2022.

This weekend’s rain, Van Horn said, “is good, but the deficit we’re talking about now…it’s unlikely that we would make [that] up.”