Hydrologists say recent rains haven't ended Oregon drought yet
While many Oregonians in the Northwest region likely heaved a sigh of relief when rain returned last week, Scott Oviatt of the Oregon Snow Survey warns not to celebrate too quickly.
"The common perception is: 'Well, it rained, so now the drought is over,'" Oviatt said. "Unfortunately, it doesn't work that way."
Even with the heavy snow events that dampened much of the Hood, Sandy and Lower Deschutes region this February, Oviatt said that since March 1, there has been very little precipitation, so it's going to take more than a few good showers this fall to prevent a repeat of dry conditions next year.
"The conditions are still pretty dry," Oviatt said, pointing out that while the Northwest portion of the state has seen steady seasonal showers in recent weeks, just over the mountain in Hood River and farther in Wasco County, the land is still fairly parched.
Part of why the recent rains are a good sign, but not enough, is because there is a substantially lower reserve than usual.
"After the dry time we've had, all SNOTEL sites are at all-time lows," Oviatt said, including the Mount Hood SNOTEL site at Timberline Lodge. "We haven't seen a low like this in 20-40 years of records."
What reserved moisture is in the Hood, Sandy and Lower Deschutes basin, Oviatt added, is mostly left over from the beginning of the year's heavy snow and still only at 92% of average. Last year the precipitation level on Sept. 30 was very similar, sitting at 89% of average.
"Before these past two weeks, all of our streams were at 70% of average," Oviatt said, adding that while the dry period for most of 2021 doesn't bode well, he's hopeful that these "typical fall patterns" of showers are "promising."
"We want those good flows going into winter," Oviatt said of the streams in the basin, which have received some help from recent rains. "Predictions show above normal precipitation (in this upcoming water year, which starts Oct. 1). If that comes true, we're headed in the right direction. We just need to keep getting these systems coming in. November through January are crucial; we get our majority of rainfall and snowpack accumulation then."
Otherwise, Oviatt said, "if we are below normal precipitation again this winter, we'll be back where we were this summer next year.
"We should be guarded at this point because of how dry it's been the past few years," Oviatt said. "We need to keep that moisture coming in through winter."
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