Drought Status Update for the Pacific Northwest

Current Conditions for the Pacific Northwest

For an in-depth recap of current conditions, please see this week’s Pacific Northwest Drought & Climate Outlook Webinar.

• Drought conditions for most of the region continued to deteriorate throughout the summer or remain the same (Figure 1). 
• Mid-August storms and cooler weather brought a brief reprieve to drought and wildfire conditions for some areas of the Pacific Northwest, but did not end either.
• Much-above-normal temperatures and evaporative demand continue to define the summer and are anticipated to continue over the next several weeks. 
• Streamflow averages across the Pacific Northwest continue to be well below normal since mid-June. 
• Over the last 7 days, most of the region was extremely dry, with small amounts of precipitation falling only in northwest Washington and southwest Oregon. However, over the same time period, temperatures were below normal across most of the region.

Figure 1: 5-Week U.S. Drought Monitor Change Map (Since July 23, 2024)

Key Takeaway: Drought intensified across central Washington, central Idaho, and southeastern Oregon, with one- to two-class degradations. Drought conditions across other parts of the region did not change from mid-July into late August. 

Pacific Northwest Drought Impacts 

• Low humidity, lack of precipitation, and extreme winds dried out vegetation and further increased wildfire risks across the region. These conditions led native grasses to cure (the process in which plants dry out and enter dormancy after the summer growing season) early, which exacerbated wildfire risk and decreased forage quality. 
• Pasture and range conditions are poor because of lack of precipitation, wildfires, grasshopper outbreaks, extreme heat, and low soil moisture. The poor range conditions triggered supplemental feeding of livestock, some cattle sell-offs, and trucking water to livestock. 
• Low streamflows in the Methow River, Yakima River Basin, Wood River, and the Blackfoot River prompted significant concerns about aquatic life. Additional fishing restrictions were implemented across several basins as a result.   
• Streamflows across all states continue to be well below normal, with some extremely low conditions. Persistent below-normal precipitation and above-normal temperatures throughout the water year contributed to these low base flows (Figure 2).
• In Washington, low flows in the Methow River resulted in junior water right holders throughout the basin being unable to access their full water allotments. Additionally, the Rimrock Retreat Fire compromised Yakima Tieton Irrigation District’s infrastructure, reducing its ability to supply water to users. 
• In northern Idaho, spring wheat shows signs of damage, and in Montana, ranchers began destocking herds and backstocking hay. 
• Air quality deteriorated across large parts of the region due to smoke from large wildfires, such as the Paddock Fire in Idaho, Durkee and Cow Valley Fires in Oregon, and Pioneer Fire in Washington. 

Report your local drought impacts through a Condition Monitoring Observer Report:

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Figure 2: Duration Hydrograph of 7-Day Average runoff in the Pacific Northwest (August 27, 2024)

Key Takeaway: Averaged across the Pacific Northwest, streamflow was below normal (10th–24th percentile) to much below normal (5th percentile) since mid-June of this year.

Figure 3: Major U.S. Bureau of Reclamation Storage Reservoirs in the Yakima Basin

Key Takeaway: Much-above-normal temperatures and much-below-average precipitation across the Yakima Basin in Washington resulted in water levels below the capacity of some reservoirs. Water levels in three of five reservoirs were well below 50% of capacity, with Cle Elum reservoir at 8% of capacity.

Figure 4: Mudslides Caused by Heavy Precipitation on Burn Scar

Key Takeaway: Burned vegetation in Washington’s Easy Fire exposed soil that could not absorb the heavy rainfall, leading to mudslides that closed State Route 20.

Figure 5: Drought Impacts in the Oregon Range

Key Takeaway: Below-normal precipitation, above-average temperatures, and high evaporative demand contributed to drying soil moisture and deteriorating conditions throughout shrublands in central and eastern Oregon. 

Outlooks and Potential Impacts for the Pacific Northwest

For an in-depth overview of seasonal conditions and climate outlooks, please see this week’s Pacific Northwest Drought & Climate Outlook Webinar. 

• The National Weather Service Climate Prediction Center’s outlooks for September predict above-normal temperatures across the region, except in Washington, where near-normal temperatures are expected. Precipitation is predicted to be near-normal for most of the region, with above-average precipitation expected for western Washington (Figure 6). 
• The U.S. Seasonal Drought Outlook (Figure 7) indicates drought is expected to improve or end in regions east of the Cascade Range in Washington and Oregon. Drought is expected to persist across southeastern Oregon, northern Idaho, and western Montana. Given these seasonal predictions, adverse effects on water supply, human health, and agricultural production in parts of the region are likely to continue. 
• The risk of wildfire is expected to remain high into the end of summer and early fall; the National Fire Preparedness Level is 4. The National Significant Wildland Fire Potential Outlook, released on August 1, 2024, indicates that fire potential will remain above-normal across most of the Pacific Northwest through September (Figure 8). 
• The El Niño–Southern Oscillation (ENSO) is expected to remain in ENSO-neutral status for the next several months, with La Niña favored to emerge during September to November. La Niña tends to bring cooler, wetter winters in the Pacific Northwest. 

Figure 6: 1-Month Precipitation and Temperature Outlook for September 2024 

Key Takeaway: According to the National Weather Service Climate Prediction Center, temperatures are likely to be above normal for the Pacific Northwest, except in Washington. Most of the region has equal chances for above-, near-, or below-normal precipitation. Northwestern Washington is likely to receive above-normal precipitation during September 2024.

Figure 7: U.S. Seasonal (3-month) Drought Outlook

Key Takeaway: The National Weather Service Climate Prediction Center’s U.S. Seasonal Drought Outlook (valid August 15–November 30, 2024) indicates that drought severity and extent will improve or end in regions east of the Cascade Range in Washington and Oregon. Drought persistence is likely across southeastern Oregon, northern Idaho, and western Montana. 

Figure 8: Significant Wildland Fire Potential Outlook for September 2024

Key Takeaway: Nearly all of the Pacific Northwest has significant (above-normal) wildland fire potential for September 2024. Western Oregon and far northern Idaho are at normal risk. 

Resources

• Farm and Ranch Stress Assistance Network
• Register for the next Pacific Northwest Drought Early Warning System Webinar on Monday, October 28 at 11 a.m. PT.
• View more maps and data on Drought.gov's state pages:
  • Idaho
  • Montana
  • Oregon
  • Washington
• More local information is available from the following resources:
  • Your state climatologist
  • Your local National Weather Service office

Prepared By

Jason Gerlich
Cooperative Institute for Research in Environmental Science (CIRES), NOAA’s National Integrated Drought Information System

Guillaume Mauger
Office of the Washington State Climatologist, University of Washington

Larry O’Neill
Oregon Climate Service, Oregon State University

Erica Fleishman
Oregon Climate Change Research Institute, Oregon State University

Caroline Mellor
Washington State Department of Ecology