Precipitation lags across Oregon as drought lingers

By GEORGE PLAVEN
Oregon Capital Bureau

PORTLAND — A new water year is off to a slow start in Oregon, where much of the state remains mired in a multi-year drought. 

Warm and dry weather persisted through mid-October, digging an early deficit for precipitation in most basins — particularly those in central and southern Oregon, where drought conditions are the worst.

However, climate experts say there is still plenty of time to catch up and La Nina could bring ample rain and mountain snow this winter to the Pacific Northwest. 

Every drop is needed to reverse what has been a painfully long drought dating back to November 2019, said Larry O’Neill, Oregon state climatologist. 

“We need at least an average amount of precipitation, and average temperatures,” O’Neill said. “Precipitation is the key. We (also) desperately need the snowpack to be above-average, and we need that snowpack to stick around past April 1. That will set us up pretty well for recovering.”

While overall precipitation since Oct. 1 has been “slightly discouraging,” O’Neill said the peak wet season doesn’t typically begin until later in the winter and early spring. 

According to the U.S. Drought Monitor, about 95% of Oregon is in some stage of drought, ranging from “abnormally dry” to “exceptional,” the highest possible category. 

The only exceptions to drought are in northeast Oregon, including parts of Umatilla, Morrow, Union and Wallowa counties, as well as a sliver of Curry County along the southwest coast. 

Data from the USDA Natural Resources Conservation Service shows the Umatilla, Walla Walla and Willow basins in northeast Oregon have received 126% of their average water year precipitation as of Nov. 28. That’s good news for the region’s dryland wheat farmers, O’Neill said. 

Other basins have not been as fortunate. Those hardest hit by drought in Central and Southern Oregon have only received about 75% of average precipitation, including the Upper Deschutes, Crooked, Klamath, Rogue and Umpqua basins. 

“We haven’t really recovered in regions where we really need to see improvement,” O’Neill said. 

The typically rainy Willamette Basin is also just 80% of average for precipitation since the water year began on Oct. 1. Through Oct. 20, there was no recorded precipitation in Portland, Salem and Eugene, which hadn’t happened since 1987. However, it has rained since then.

Not only was it dry, but it was also the second-warmest October on record for Oregon, said Matt Warbritton, hydrologist for the NRCS in Portland.

Warbritton said more precipitation is sorely needed to boost low soil moisture in drought-stricken basins. If the ground is too dry, he said it can absorb snowmelt before it reaches streams, rivers and reservoirs that farmers depend on during the irrigation season.

But there are reasons for encouragement.

Snowpack is largely near- or above-normal statewide, and La Nina has the potential to bring cooler, wetter weather that would allow snow to remain high in the mountains for longer into the year and melt gradually when it is needed most by farms and fish.  

“All we can really do is hope for an above-normal snowpack season,” Warbritton said. “We’re still very much in a dry phase. It may not seem like it, because we had some early season snowpack. But that precipitation, we just need more of it.”