Climatology

April rains ‘not nearly enough’ to overcome Northwest drought, wildfire risk, experts say

Spring showers have helped alleviate drought and wildfire risks in Western Washington but large swaths of the Pacific Northwest remain dry, if not drier than usual.

Last month was the state’s 10th-wettest April in 128 years, according to the US Drought Monitor. And yet, more than half of Washington state is abnormally dry or experiencing moderate drought, nearly 25% is in the midst of severe drought and 3.9% is facing extreme drought.

As summer approaches, the accumulating impacts of consecutive dry seasons are impacting snowpack, streamflow and water resources across the region.

“To be clear, it’s been cool and wet in Washington,” Washington State Climatologist Nick Bond said Wednesday during a briefing on drought conditions in the Pacific Northwest. Bond said the chances of a statewide heat wave similar in magnitude to what the region saw last year are remote.

“All that being said,” he added. “Mother nature has shown us what’s possible.”

In the Columbia Basin, the last two years were some of the driest in state history. Extreme drought conditions continue through the lower basin and into Grant County and moderate drought persists across the upper basin and into northeastern parts of the state. The northern Cascades saw rejuvenating rains last month – which boosted snowpack and helped delay seasonal melting – but the same cannot be said of Eastern Washington and North Idaho, both of which saw below-normal precipitation.

While Western Washington and Oregon are generally faring better than the eastern regions of the Cascades, summer droughts and wildfires are becoming more frequent and intense due to climate change.

About 68% of the Northwest is experiencing drought while 20% is experiencing extreme or exceptional drought, according to Britt Parker from the National Oceanic and Atmospheric Administration’s National Integrated Drought Information System and the University of Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences.

“This wet and cool April is not nearly enough, though, to overcome long-term precipitation deficits and low snowpack,” Parker said Wednesday. “While April precipitation did aid in streamflow recovery and reservoir storage in some areas, it is important to note that we still expect drought to impact much of the region including southern Oregon, portions of Eastern Washington and southern Idaho.”

Despite unusually high precipitation in April, drought conditions of varying severity persist in central Washington, central Oregon and big stretches of Idaho.

In parts of Oregon, last year’s spring was the state’s driest on record. Just last month, Idaho state officials issued an emergency drought declaration for all 34 counties south of the Salmon River.

Dry conditions, high temperatures and stretched water supplies can blaze a pathway for wildfires. And in the Pacific Northwest they’re becoming a growing threat.

Drought conditions reflect fire risks, Eric Wise from the Northwest Area Coordination Center said during the briefing Wednesday.

The risk of significant fires in the Northwest is low through May, according to nationwide projections published earlier this month, but that risk is elevated in central Oregon through June and could expand into southwest Oregon and central Washington in July.

In southern California, residents were preparing for an intense wildfire season when a coastal blaze emerged in Laguna Niguel. The fire – which sparked on May 11 and rapidly expanded to an area of ​​200 acres and destroyed 20 homes – was completely contained, Orange County officials announced Tuesday.

In recent years, Western Washington residents have been smoked out during the summer wildfire season by blazes on all sides in British Columbia, Eastern Washington, Oregon and California.

The US Southwest faces above normal wildfire risk through May and June but that could spread in southern and western Colorado before recovering in July. Above normal fire risk is likely to expand by July to southwest Oregon and central Washington, and possibly most of the Northwest in August.

More rain helped the region’s snowpack which had been declining through the first quarter of the year. Snow-water equivalent was reported to have risen to or surpassed the average for Washington, central and northeastern Oregon by the end of April. Snowpack improved in the southern parts of Oregon but they remain well behind normal for this time of year.

Heat waves and wildfires are compounded by drought – and vice versa – in a violent cycle that continues to threaten water resources across the country.

“As we move forward with the changing climate,” said Oregon State Climatologist Larry O’Neill, “we do expect these sort of heat events to happen a little bit more frequently than they have in the past.”

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