Special Release: Mid-March Snowpack & Water Supply Outlook Update
Significant snow drought persists as irrigation season is underway in Oregon
Widespread and severe snow drought persists across much of Oregon as of March 16. Although an atmospheric river brought some snow accumulation to primarily northwestern and northeastern Oregon, abnormally warm temperatures during portions of the storm cycle limited how much precipitation fell as snow at higher elevations in the mountains. The snow that did accumulate was far from enough to make up for the substantial snowpack deficits already in place.
Snowpack deficits at SNOTEL stations across much of the Cascade Range are currently among the greatest in the entire western U.S., with many stations reporting at or near record low snowpack. Conditions are similarly poor in the Blue Mountains and on Steens Mountain, where several stations are also at or near historic lows.
Oregon’s typical peak snowpack period, March 11 through March 30, is approaching or has already passed for most major basins. Without significant additional snow accumulation, many areas have already reached an early and exceptionally low peak, while others have melted out. Examples include:
- Ochoco Meadows SNOTEL (Crooked River Basin): Peak snowpack reached only 17% of normal, and snow melted out 46 days earlier than normal.
- Klamath Basin: Peak snowpack occurred on February 24, 19 days earlier than normal.
- Umatilla and John Day Basins: Four SNOTEL stations reported snow meltout 34 to 70 days earlier than normal.
These conditions highlight how widespread and exceptional this year’s snow drought has become in several basins across the state.
In addition to low snowpack, several major basins are also experiencing below normal precipitation for the water year. Some areas, including Hood River and Lower Deschutes Basin, Harney Basin, and parts of northeastern Oregon, have received near normal precipitation. However, even normal precipitation is not enough to offset the significant deficits in snowpack, which serves a critical role in sustaining spring and summer streamflows, especially in Oregon’s arid basins.
What This Means for Spring and Summer Water Supply
The outlook for spring and summer water supply is poor across much of the state, particularly east of the Cascades where communities depend heavily on snowmelt for reliable runoff. Even with additional storms this spring, existing deficits are likely too large to overcome. Rainfall may temporarily boost streamflow, but without a robust snowpack to melt gradually through late spring and early summer, rivers and reservoirs will have little replenishment when water demand is highest.
Implications for Drought, Ecosystems, Agriculture, and Wildfire
Low snowpack and early meltout have far-reaching consequences:
- Drought: Low snowpack in snow-dependent basins is a strong indicator of water shortages heading into the summer. Below-normal water-year precipitation can compound these shortages, increasing the likelihood of worsening drought conditions.
- Ecological Impacts: Gradual snowmelt helps moderate stream temperature and sustain cool-water habitat for fish and wildlife. Snow cover also protects soils after fall rains, preserving moisture that supports vegetation in the spring and summer.
- Agriculture: Producers depend on both the timing and volume of snowmelt to supply irrigation water throughout the growing season. Snow drought and early meltout reduce water availability when crops need it most.
- Wildfire Risk: While summer weather and human activity ultimately shape wildfire season, warm and low-snow winters can set the stage for drier fuels earlier in the year, increasing the potential for a longer and more active fire season.
Looking Ahead
The combination of a historically warm winter and widespread snow drought points to significant water-supply challenges for Oregon in the months ahead. With much of the state entering spring already facing significant moisture deficits, the stage is set for elevated drought risk and associated impacts across ecosystems, agriculture, and communities. Monitoring conditions and preparing for potential shortages will be essential as the summer season approaches.
Links to Current Conditions, Water Supply Forecasts, and the Water Supply Outlook Report
Snow Water Equivalent (current) – Percent of Normal
Water Year-to-Date Precipitation – Percent of Normal
Month-to-Date Precipitation
Weekly Water Supply Guidance Forecasts (select forecast points only)
March 1 Water Supply Outlook Report