Drought Information Statement for Eastern OR & South Central WA Valid August 12, 2024 Issued By: NWS Pendleton Contact Information: pdt.operations@noaa.gov This product will be updated if drought conditions change significantly. Please see all currently available products at https://drought.gov/drought-information-statements. Please visit https://www.weather.gov/pdt/DroughtInformationStatement for previous statements Please visit https://www.drought.gov/drought-status-updates/ for regional drought status updates. Severe Drought is affecting portions of the Kittitas Valley Moderate drought is affecting portions of the central WA Cascades, Kittitas, Yakima, Central OR, and portions of northeast OR Abnormally dry conditions continue over most of the area with mainly well below normal precipitation seen area-wide the last 30 days Above normal significant fire potential is forecast through September for the entire area becoming normal significant fire potential for October and November (Northwest Coordination Center) 1 Link to the latest U.S. Drought Monitor Drought intensity and Extent D2 (Severe Drought): Eastern portions of the Kittitas Valley D1 (Moderate Drought): Portions of the central Washington Cascades, Kittitas and Yakima counties, central and north central Oregon, the Ochoco-John Day Highlands, Blue Mountains, and Wallowa County D0: (Abnormally Dry): All other areas except portions of the OR and WA Columbia Basin and Simcoe Highlands U.S. Drought Monitor Link to the latest 4-week change map for the Pacific Northwest National Weather Service Pendleton, OR One-Week Drought Monitor Class Change Drought Worsened (1 Class Degradation): A thin swath of the Blue Mountains and north central Oregon Four-Week Drought Monitor Class Change Drought Worsened (1 Class Degradation): Portions of the OR Cascades, north central OR, Ochoco-John Day Highlands, Blue Mountains, the Grande Ronde Valley, and southeast WA Image Captions: Right - 4 Week Drought Class Change Left - 1 Week Drought Class Change Data Courtesy U.S. Drought Monitor and Drought.gov Data over the past 7 and 28 days ending August 6, 2024 Recent Change in Drought Intensity Mainly well below normal precipitation areawide (less than 50 percent of normal) Pockets of near to above normal precipitation (100-200 percent of normal) across central OR, the Blue Mountains, Grande Ronde Valley, and Wallowa county Highest precipitation amounts were 1 to 2 inches along portions of the Wallowa Mountains Image Captions: Right - Precipitation Amount for Pacific NW Left - Percent of Normal Precipitation for Pacific NW Data Courtesy NWS Water Prediction Service Data over the past 30 days ending August 11, 2024 Precipitation - Last 30 Days Image Captions: Right - Precipitation Amount for Pacific NW Left - Percent of Normal Precipitation for Pacific NW Data Courtesy High Plains Regional Climate Center Data for the current water year ending August 12, 2024 Below normal precipitation (50-100%) continues for the current water year over much of the area The exception: areas of near to above normal precipitation (100-120%) seen across parts of the OR Cascades and from the Ochoco-John Day Highlands north north into the southern Blue Mountains, and OR Blue Mountain Foothills into the western WA Columbia Basin This could largely be attributable to precipitation in December 2023, January 2024, and May 2024 Precipitation - Current Water Year Well above normal high temperatures the last 30 days with temperatures 3-8 degrees above normal except for a small area of 1-3 degrees above in the eastern Simcoe Highlands Image Captions: Right - Temperature for Pacific NW Left - Percent of Normal Precipitation for Pacific NW Data Courtesy High Plains Regional Climate Center Data for the last 30 days ending August 8, 2024 Temperature - Last 30 Days Hydrologic Impacts Much below normal streamflow (<10th percentile) across the Upper Columbia-Entiat basin, below normal streamflow (10th-25th percentile) across the Naches, Upper and Lower Yakima, Lower Snake, Lower Snake-Tucannon, Lower Snake-Asotin, Umatilla, North and Middle Forks John Day River, Upper and Lower Grande Ronde and Imnaha basins, and above normal (76th-90th percentile) for the Walla Walla basin, elsewhere near normal streamflows (25th-75th percentile). Reservoir levels are near to slightly below normal (45-80% full) with a few outliers below to well below normal (15-35%) - this may affect fish and other aquatic species as well as recreation activities through the summer, especially in the Columbia Basin. Snowpack Impacts All snow telemetry (SNOTEL) monitoring sites show snow has melted/no remaining snow. There are no known impacts at this time. Agricultural Impacts There are no known impacts at this time Fire Hazard Impacts There are no known impacts at this time Other Impacts Washington Drought Emergency declared for all counties east of the Cascades Jefferson County Oregon Drought Emergency Declared Mitigation actions Please refer to your municipality and/or water provider for mitigation information See/submit Condition Monitoring Observer Reports (CMOR) and view the Drought Impacts Reporter Summary of Impacts Image Captions: Right - USGS 7-day average streamflow station map valid August 11, 2024 Left - USGS 7-day average streamflow HUC map valid August 11, 2024 Data Courtesy USGS Water Watch Main Takeaways The Upper Columbia-Entiat basin has well below normal streamflow (<10 percent of normal) The Naches, Upper and Lower Yakima, Lower Snake, Lower Snake-Tucannon and Lower Snake-Asotin basins have below normal streamflow (10th-24th percentile) The Walla Walla basin has above normal flow (76th-90th percentile) Other river, stream, and creek flows are near normal (25th-75th percentile) Impacts No known impacts at this time Reduced streamflow may be detrimental to aquatic species and recreational activities. Hydrologic Conditions and Impacts - Washington Image Captions: Right - USGS 7-day average streamflow station map valid August 11, 2024 Left - USGS 7-day average streamflow HUC map valid August 11, 2024 Data Courtesy USGS Water Watch Hydrologic Conditions and Impacts - Oregon Main Takeaways Below normal (10th-24th percentile) for the Umatilla, North and Middle Forks John Day River, Upper and Lower Grande Ronde and Imnaha basins Above normal (76th-90th percentile) for the Walla Walla basin Other river, stream, and creek flows are near normal (25th-75th percentile) Impacts No known impacts at this time Reduced streamflow may be detrimental to aquatic species and recreational activities. Main Takeaways The mountain snowpack is gone at all locations in the mountains of Northeast Oregon and Southeast Washington Impacts No known impacts at this time Snow water equivalent is related to the amount of water stored in snowpack. The lack of snow can affect the amount of available water for spring and summer snow melt. This can have impacts on water storage, irrigation, fisheries, vegetation, municipal water supplies, and wildfire. Image Captions: Oregon and Washington SNOTEL Current Snow Water Equivalent % of Normal Data Courtesy USDA Natural Resources Conservation Service Daily Value as of July 11, 2024 Snowpack Conditions and Impacts ay l 4% 8% Main Takeaways Below to much below normal water supply (52-83% of the 1991-2020 normal) is forecast for the April-September 2024 period across much of south central and southeast WA into northeast Oregon Below-normal water supply (75-90%) is forecast across much of Wallowa county, and parts of the eastern slopes of the WA Cascades and Simcoe Highlands Near-normal water supply (83-103%) is forecast across central OR east into the southern Blue mountains and the Ochoco-John Day Highlands Impacts No known impacts at this time Low reservoir levels would be expected to affect agriculture production, fish, and other aquatic species. Image Caption: Ensemble Streamflow Prediction Natural Forecast Data Courtesy NOAA NWS Northwest River Forecast Center Issued August 11, 2024 Forecast (% of Normal) Link to the latest Northwest River Forecast Center Water Supply Forecast. Water Supply Forecast - April - September 2024 Forecast (% of normal) Main Takeaways Above normal wildland fire potential for all areas for August and September 2024 Near normal wildland fire potential (i.e., very low risk) for all areas for October and November 2024 Significant wildland fires are expected at typical times and intervals during normal significant wildland fire potential conditions Image Caption: Left - August 2024 Right - September 2024 Data Courtesy National Interagency Coordination Center Issued August 1, 2024 Link to Wildfire Potential Outlooks from the National Interagency Coordination Center. Fire Hazard Impacts - August through November A persistent trough over the Pacific Northwest will give the area a chance of light rain and mountain thunderstorms for the next week, especially Thursday into next weekend Most lower elevation areas will get a tenth of an inch or less while the mountains will get a tenth to a half of an inch Visit weather.gov/Pendleton for the latest weather forecast Image Caption: Weather Prediction Center 7-day precipitation forecast Seven Day Precipitation Forecast Main Takeaways Leaning towards below normal temperatures area-wide (33-60%) Leaning towards above normal precipitation area-wide (33-50%) Image Captions: Left - Climate Prediction Center 6-10 Day Temperature Outlook. Right - Climate Prediction Center 6-10 Day Precipitation Outlook. Valid August 17-21, 2024 Link to the latest Climate Prediction Center 6 to 10 day Temperature Outlook and Precipitation Outlook. 6-10 Day Outlook Main Takeaways Below normal temperatures (33-40% chance) in WA and OR, except equal chance of above, near, or below normal temperatures in the eastern portions of the area Above normal precipitation (33-50% chance) in WA and OR Image Captions: Left - Climate Prediction Center 8-14 Day Temperature Outlook. Right - Climate Prediction Center 8-14 Day Precipitation Outlook. Valid August 19 - 25, 2024 Link to the latest Climate Prediction Center 8 to 14 day Temperature Outlook and Precipitation Outlook. 8-14 Day Outlook Image Captions: Left - Climate Prediction Center Seasonal Temperature Outlook. Right - Climate Prediction Center Seasonal Precipitation Outlook. Valid August 2024 Main Takeaways for August Odds favor above normal temperatures area wide (40-70%) Odds favor below normal precipitation area wide (33-50%) Link to the latest Climate Prediction Center Monthly Outlook. Monthly Climate Outlook Image Captions: Left - Climate Prediction Center Seasonal Temperature Outlook. Right - Climate Prediction Center Seasonal Precipitation Outlook. Valid August, September and October 2024 Main Takeaways for August-September-October Odds leaning towards equal chances of above, near and below normal temperatures, except leaning towards above normal temperatures (33-40%) for the eastern and southern portions of the area Odds leaning towards equal chances of above, near and below normal precipitation area-wide Link to the latest Climate Prediction Center Seasonal Outlook. Seasonal Climate Outlook Main Takeaways Drought is expected to persist over Kittitas and eastern Yakima counties, the northern Blue Mountains, Wallowa county and central OR into the western Ochoco-John Day Highlands Drought is expected to develop over the rest of southeast WA and northeast OR These areas are vulnerable due to below normal precipitation and the warm seasonal outlook Possible Impact Reduced streamflows and reservoir levels, possible reduction in agricultural yield, crop loss, and poor pasture conditions where irrigation water is not available. Image Captions: Right - Climate Prediction Center Monthly Drought Outlook Released July 31, 2024 Left - Climate Prediction Center Seasonal Drought Outlook Released July 31, 2024 The latest drought outlooks can be found on the CPC homepage. Drought Outlook