FGUS76 KPQR 102131 ESFPQR Oregon Peak Flow Forecast National Weather Service Portland OR 1215 PM PST Tuesday Mar 10 2026 OREGON WATER SUPPLY SUMMARY AS OF March 10TH, 2026 The water supply forecast for the spring and summer of 2026 is below average for most of the Oregon watersheds, ranging from near normal along the Columbia River to below 40% of normal water supply in Southeast Oregon. It is forecasted that overall river peaks in Oregon are likely to be lower than the 30 year normal depending on elevation, temperature, and snow accumulation, with a low likelihood of exceeding flood stage. Note that conditions and water supply forecasts may evolve through the rest of winter and spring. Precipitation so far this water year (Oct 2025 to Feb 2026) is near to below average for most of the center of the state, with the central northern and southern border near to above average. Temperatures for the water year are overall above average statewide with even higher deviations above average (1991 -2020) present east of the cascades. As of March 3rd, over 20% of Oregon is in drought. Refer to the sections below and links provided for additional details and updates through the summer regarding precipitation, seasonal climate outlooks, reservoirs, streamflow, and water supply forecasts. More information can be found : www.weather.gov/media/pqr/WaterSupplyOutlook.pdf Peak Stream Flow Forecast Peak stream flow will be determined by when the snow starts to rapidly melt off. It is forecasted that overall river peaks in Oregon are likely to be lower than the 30 year normal depending on elevation, temperature, and snow accumulation, with a low likelihood of exceeding flood stage. As of March 11th, there are 4 basins in Oregon with a 10% probability of peak flow exceeding threshold: Grand Ronde at Troy, Wilson River near Tillamook, Pudding River at Aurora, and Imnaha River at Imnaha. The majority of the basins in the state are more likely to have their river flow peak in March and April. Higher elevation watersheds have a low potential to peak in June. These dates and timings can be significantly altered with differences in future precipitation, temperature, and flow regulation. More details per site can be seen on the NWRFC website on peakflow. Snow water Equivalent amounts, outlooks, and previous peaks can help forecast these values and timing. Most of Oregon's snow water equivalent amounts are lower than normal peak amounts. It is forecasted that river peaks will overall be lower than the 30 year normal with timing near or earlier than normal depending on elevation, temperature, and snow density. NWRFC has extensive forecast that can be seen at https://www.nwrfc.noaa.gov/ws/index.html?version=20190313v1. CBRFC has forecasted southern Oregon Peak flows in late April and May. More information at cnrfc.noaa.gov/water_resources_update.php PRECIPITATION AND TEMPERATURES ACROSS OREGON In February, precipitation ranged from below average around the Deschutes basin and above 190% at The Dalles . Due to the overall statewide 120% increase in February, the overall precipitation values are closer to normal from the start of the water year. Precipitation for the 2026 water year thus far (Oct 2025 – Feb 2026) ranges from below average in the center of the state near the Deschutes basin to above average amounts in the Harney Basin, around The Dalles, and north west of the coastal range . Southwest Oregon is below normal with the Coquille River basin reaching 58% of normal precipitation. Temperatures across the state have been above average for the 2026 water year (October 2025 – February 2026), with an average anomaly of 4.3 degrees above normal. Higher elevations, including the Cascades and parts of the Coast Range, saw temperatures 1 to 3 degrees above average. Eastern Oregon experienced even warmer conditions, averaging 2.5 to 5 degrees above normal for the water year. Details on precipitation and temperatures: * NOAA National Weather Service - Northwest River Forecast Center www.nwrfc.noaa.gov/water_supply/wy_summary/wy_summary.php * NOAA NWS - California-Nevada River Forecast Center (Klamath basin) www.cnrfc.noaa.gov/water_resources_update.php * Westside Drought Tracker Precipitation & Temperature graphics Climate Mapper SNOWPACK ACROSS OREGON As of March 5, 2026, mountain snowpack is significantly below average statewide, in terms of the water content of the snowpack. In terms of percent of median, basin values range from 22% to 85%. More snow accumulation is possible through April although given the low snowpack as of early March, it is unlikely to bounce back to average levels. Additional snowpack information: * NOAA National Weather Service - Northwest River Forecast Center www.nwrfc.noaa.gov/snow/ * USDA Natural Resources Conservation Service nwcc- apps.sc.egov.usda.gov/imap/ PRECIPITATION AND TEMPERATURE OUTLOOK The Climate Prediction Center issues monthly and seasonal outlooks that weigh the likelihood of near-normal, above-normal, or below-normal temperatures and precipitation. The temperature outlook does not show a strong trend for spring. However, above- normal temperatures are predicted for the summer months. Similarly, while the overall precipitation outlook lacks a strong signal, below-normal precipitation is favored in the early summer months, shown lower right. Visit www.cpc.ncep.noaa.gov for more about seasonal outlooks. ENSO conditions transition from La Niña advisory this month to ENSO- neutral, with ENSO-neutral likely persisting through the Northern Hemisphere summer ( June-August 2026). Beginning February 1st, the official ENSO index is the Relative Oceanic Niño index (RONI), which is the traditional ONI with the tropical mean (20S-20N) sea surface temperature anomalies subtracted out. For more information on RONI, please examine this 2-page flyer: https://www.weather.gov/media/climateservices/RONI.pdf RESERVOIRS Reservoir data is provided by the Natural Resources Conservation Service, the Bureau of Reclamation, and the US Army Corps of Engineers. Irrigation reservoirs range in their storage based on the available water inflowing into their system and their release schedule. The Umatilla River basin Reservoirs are about a third full, Southeastern Oregon reservoir is about halfway full, and the Deschutes and Rogue Reservoir systems are about two third full. Owyhee, located in southeast Oregon, is the largest irrigation reservoir in the state. It has observed storage of about 446,000 acre-feet, which is 62 percent of capacity and 130 percent of average for this time of year. Reservoir storage for reservoirs across the western portion of the state is generally below average ranging from 4 to 42% of the expected elevation. The main exceptions are reservoirs in the western headwaters of the Willamette, where reservoir storage ranges 7-22% above the rules curve. Flood control reservoirs in western Oregon will gradually refill through the late winter and spring. Additional reservoir information: * www.nwd-wc.usace.army.mil/nwp/teacup/willamette/ * www.usbr.gov/pn/hydromet/select.html * www.wcc.nrcs.usda.gov/basin.html OBSERVED STREAMFLOW Observed runoff so far this water year has been below normal conditions for most watersheds statewide, particularly so for watersheds in south and east Oregon. The only areas with near-average runoff are northwest Oregon, near the Coast Range. Since last month, Eastern Oregon Runoff near Owyhee Dam, Umatilla, and Grand Ronde have departed from normal by more than 10%. Visit waterwatch.usgs.gov for details on observed streamflow. Runoff data is available at www.nwrfc.noaa.gov/natural/index.html at water year and monthly time scales for several locations in Oregon. WATER SUPPLY SEASONAL FORECASTS Water supply forecasts for April-September runoff volume are below normal for most Oregon watersheds, with the exception being near the coastal range in northwest Oregon and near The Dalles where it is near normal conditions. Central Eastern Oregon’s water supply is near or below 50% of water supply normals. The forecast for the Columbia River at The Dalles, which is a good index of conditions across the Columbia Basin, is 94 percent of average for April-September. Details on basin-scale water supply forecasts: * NOAA NWS - Northwest River Forecast Center www.nwrfc.noaa.gov/ws/ * NOAA NWS - California-Nevada RFC (Klamath basin) www.cnrfc.noaa.gov/water_resources_update.php * USDA Natural Resources Conservation Service www.wcc.nrcs.usda.gov/wsf/ lap